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uniapp 头像合成canvas,下载图片

作者:互联网

<template>
    <view class="cloud_box">
        <view class="titels">换头像活动</view>
        <view class="box">
            <view v-for="(item,index) in modelList" :key="index" class="items" @tap="clickTab(index)">
                <view class="border" :class="currentIndex==index?'active':''">
                    <image :src="item.url" class="model_img"></image>
                </view>
            </view>
        </view>
        <view class="result">
            <view class="left border active">
                <image :src="modelList[currentIndex].url" class="model_img"></image>
                <image :src="chooseImg" class="choose_img"></image>
            </view>
            <view class="flex_flow">
                <button type="primary" @tap="uploadFile">上传图片</button>
                <button type="warn" @tap="showResult">生成头像</button>
            </view>
        </view>
        <canvas style=" width: 750rpx; height: 500rpx;opacity: 0;" canvas-id="myApp" id="myApp"> </canvas>
        <gmy-img-cropper ref="gmyImgCropper" :quality="1" cropperType="fixed" :imgSrc="imgSrc" @getImg="getImg">
        </gmy-img-cropper>
    </view>
</template>

<script>
    import gmyImgCropper from '@/components/uni-img-cropper/index.vue';
    export default {
        components: {
            gmyImgCropper
        },
        data() {
            return {
                modelList: [{
                        url: 'https://oss.light-hearted.cn/storage/061e7b3940b5b2946aa5d99ff72115923a860cf320220818135359.png'
                    },
                    {
                        url: 'https://oss.light-hearted.cn/storage/cc2b80c16c949f5a28c8a6cca013d3ea3ca810da20220818140442.png'
                    },
                    {
                        url: 'https://oss.light-hearted.cn/storage/c92fa168bf46c02384fe96f3155515f3db5ed24b20220818150820.png'
                    }
                ],
                currentIndex: 0,
                chooseImg: '',
                result_img: ''
            }
        },
        onl oad() {
            this.initCavas();
        },
        methods: {
            /* 初始化canvas */
            initCavas(){
                this.cavasCtx = uni.createCanvasContext('myApp',this)
            },
            clickTab(_index) {
                this.currentIndex = _index;
                this.createCanvas();
            },
            /* 上传头像 */
            uploadFile(e) {
                // 调用实例的chooseImg方法,拉起图片选择界面,待图片选择完毕后直接进入图片截取界面
                this.$refs.gmyImgCropper.chooseImage(e);
            },
            //裁剪图片的临时路径
            getImg(e) {
                this.chooseImg = e; 
                this.createCanvas();
            },
            /* 创建画布 */
            createCanvas(){
                let _this = this;
                uni.downloadFile({
                    url: this.chooseImg,
                    success: function (res) {
                        _this.cavasCtx.save()
                        _this.cavasCtx.beginPath()
                        // _this.cavasCtx.arc(100, 100, 100, 0, 2 * Math.PI) // 圆形
                        _this.cavasCtx.rect(0, 0, 200, 200) // 矩形
                        _this.cavasCtx.clip()
                        _this.cavasCtx.drawImage(res.tempFilePath,0,0, 200, 200)
                        _this.drapImg()
                    }
                })
            },
            /* 开始作画 */
            drapImg(){
                let _this = this;
                uni.showLoading({
                    title:'上传合成中...',
                    icon:"loading"
                });
                uni.getImageInfo({
                    src:_this.modelList[_this.currentIndex].url,
                    complete: (res) => {
                        _this.cavasCtx.drawImage(res.path, 0,0,200, 200)
                        _this.cavasCtx.draw()
                        setTimeout(()=>{
                            _this.putOut()
                        },100)
                    }
                })
            },
            /* 两张图片合成成功 */
            putOut(){
                let _this = this;
                uni.canvasToTempFilePath({
                  x: 0,
                  y: 0,
                  width: 200,
                  height: 200,
                  canvasId: 'myApp',
                  success: function(res) {
                    uni.hideLoading();
                    _this.result_img = res.tempFilePath; //    合成之后的图片
                  } 
                })
            },
            // 保存图片到本地
            showResult() {
                uni.showLoading({
                    title: '保存中...',
                    icon: 'loading'
                })
                const _this = this;
                uni.saveImageToPhotosAlbum({
                    filePath: _this.result_img,
                    success: function(res) {
                        uni.hideLoading();
                        uni.showModal({
                            title: "保存成功",
                            content: "头像已经在您的相册里啦",
                            showCancel: false
                        })
                    },
                    fail(res) {
                        uni.hideLoading();
                        if (res.errMsg.indexOf("fail")) {
                            uni.showModal({
                                title: "您需要授权相册权限",
                                content: "头像已经在您的个人中心, 您可以直接去个人中心下载",
                                success(res) {
                                    if (res.confirm) {
                                        uni.openSetting({
                                            success(res) {},
                                            fail(res) {}
                                        })
                                    }
                                },
                            })
                        }
                    },
                });
            },
        }
    }
</script>

<style>
    @import url("cloudHead.css");
</style>

效果截图

           图片裁剪页面           合成界面                   结果:  

 

 

 

 

 

 

 

插件:gmyImgCropper.vue源码(带图片裁剪功能)

<template>
    <view class="container" v-show="isShow">
        <view>
            <view class="cropper-content">
                <view v-if="isShowImg" class="uni-corpper"
                    :style="'width:' + cropperInitW + 'px;height:' + cropperInitH + 'px;background:#000'">
                    <view class="uni-corpper-content" :style="
                            'width:' +
                                cropperW +
                                'px;height:' +
                                cropperH +
                                'px;left:' +
                                cropperL +
                                'px;top:' +
                                cropperT +
                                'px'
                        ">
                        <image :src="imageSrc" :style="'width:' + cropperW + 'px;height:' + cropperH + 'px'"></image>
                        <view class="uni-corpper-crop-box" @touchstart.stop="contentStartMove"
                            @touchmove.stop="contentMoveing" @touchend.stop="contentTouchEnd" :style="
                                'left:' + cutL + 'px;top:' + cutT + 'px;right:' + cutR + 'px;bottom:' + cutB + 'px'
                            ">
                            <view class="uni-cropper-view-box">
                                <view class="uni-cropper-dashed-h"></view>
                                <view class="uni-cropper-dashed-v"></view>
 
                                <!-- 截图区域顶部 -->
                                <view class="uni-cropper-line-t" data-drag="top" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
 
                                <!-- 截图区域右侧 -->
                                <view class="uni-cropper-line-r" data-drag="right" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
 
                                <!-- 截图区域底部 -->
                                <view class="uni-cropper-line-b" data-drag="bottom" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
 
                                <!-- 截图区域左侧 -->
                                <view class="uni-cropper-line-l" data-drag="left" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
 
                                <!-- 右下角截图滑块 -->
                                <view class="uni-cropper-point point-t" data-drag="top" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
                                <view class="uni-cropper-point point-tr" data-drag="topTight"></view>
                                <view class="uni-cropper-point point-r" data-drag="right" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
                                <view class="uni-cropper-point point-rb" data-drag="rightBottom"
                                    @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
                                <view class="uni-cropper-point point-b" data-drag="bottom" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove" @touchend.stop="dragEnd"></view>
                                <view class="uni-cropper-point point-bl" data-drag="bottomLeft"></view>
                                <view class="uni-cropper-point point-l" data-drag="left" @touchstart.stop="dragStart"
                                    @touchmove.stop="dragMove"></view>
                                <view class="uni-cropper-point point-lt" data-drag="leftTop"></view>
                            </view>
                        </view>
                    </view>
                </view>
            </view>
            <view class="cropper-config">
                <view class="button-box">
                    <button type="warn" @click="chooseImage">重选</button>
                    <button type="warn" @click="previewImg">预览</button>
                    <button type="primary" @click="finish">完成</button>
                </view>
            </view>
            <canvas canvas-id="myCanvas" :style="
                    'position:absolute;border: 2px solid red; width:' +
                        imageW +
                        'px;height:' +
                        imageH +
                        'px;top:-9999px;left:-9999px;'
                "></canvas>
        </view>
    </view>
</template>
 
<script>
    let sysInfo = uni.getSystemInfoSync();
    let SCREEN_WIDTH = sysInfo.screenWidth;
    let SCREEN_HEIGHT = sysInfo.windowHeight + 40;
    let PAGE_X, // 手按下的x位置
        PAGE_Y, // 手按下y的位置
        PR = sysInfo.pixelRatio, // dpi
        T_PAGE_X, // 手移动的时候x的位置
        T_PAGE_Y, // 手移动的时候Y的位置
        CUT_L, // 初始化拖拽元素的left值
        CUT_T, // 初始化拖拽元素的top值
        CUT_R, // 初始化拖拽元素的
        CUT_B, // 初始化拖拽元素的
        CUT_W, // 初始化拖拽元素的宽度
        CUT_H, //  初始化拖拽元素的高度
        IMG_RATIO, // 图片比例
        IMG_REAL_W, // 图片实际的宽度
        IMG_REAL_H, // 图片实际的高度
        DRAFG_MOVE_RATIO = 1, //移动时候的比例,
        INIT_DRAG_POSITION = 100, // 初始化屏幕宽度和裁剪区域的宽度之差,用于设置初始化裁剪的宽度
        DRAW_IMAGE_W = sysInfo.screenWidth; // 设置生成的图片宽度
    export default {
        /**
         * 页面的初始数据
         */
        data() {
            return {
                imageSrc: "",
                isShow: false,
                isShowImg: false,
                // 初始化的宽高
                cropperInitW: SCREEN_WIDTH,
                cropperInitH: SCREEN_HEIGHT,
                // 动态的宽高
                cropperW: SCREEN_WIDTH,
                cropperH: SCREEN_HEIGHT - 100,
                // 动态的left top值
                cropperL: 0,
                cropperT: 0,
                transL: 0,
                transT: 0,
                // 图片缩放值
                scaleP: 0,
                imageW: 0,
                imageH: 0,
                // 裁剪框 宽高
                cutL: 0,
                cutT: 0,
                cutB: SCREEN_WIDTH,
                cutR: "100%",
                qualityWidth: DRAW_IMAGE_W,
                innerAspectRadio: DRAFG_MOVE_RATIO,
            };
        },
        props: {
            /* 截图质量,压缩比  */
            quality: {
                type: Number | String,
                default: 1,
            },
 
            /*
             * 传入图片路径,将跳过选择图片步骤直接进入截图界面。
             * 需要特别注意:H5端 Canvas 内绘制的图像需要支持跨域访问才能成功。
             */
            imgSrc: String,
 
            /* 输出图片类型:仅支持png格式或jpg格式  */
            fileType: {
                type: String,
                default: "png",
                validator: function(t) {
                    // 这个值必须匹配下列字符串中的一个
                    return t === "png" || t === "jpg";
                },
            },
 
            /* 截取类型,自由截取free;固定比例截取(正方形)fixed  */
            cropperType: {
                type: String,
                default: "free",
                validator: function(t) {
                    // 这个值必须匹配下列字符串中的一个
                    return t === "free" || t === "fixed" || t === "ratio";
                },
            },
            ratio: {
                type: Number,
                default: 1,
            },
        },
        created() {
            if (this.imgSrc) {
                this.imageSrc = this.imgSrc;
                this.loadImage();
                this.isShow = true;
                this.isShowImg = true;
            }
        },
    
        methods: {
            setData: function(obj) {
                let that = this;
                Object.keys(obj).forEach(function(key) {
                    that.$set(that.$data, key, obj[key]);
                });
            },
 
            /* 选择图片  */
            chooseImage: function(e) {
                var _this = this;
                uni.chooseImage({
                    count: e,
                    success: function(res) {
                        if(res.tempFiles[0].size / 1024 < 1024) {
                            _this.setData({
                                imageSrc: res.tempFilePaths[0],
                            });
                            _this.loadImage();
                            _this.isShow = true;
                        } else {
                            uni.showToast({
                                title: '图片大小不能超过1024KB,当前大小' + (res.tempFiles[0].size / 1024).toFixed(2) + 'KB',
                                icon: 'none'
                            })
                        }
                    },
                });
            },
            /* 将图片加载到画布  */
            loadImage: function() {
                var _this = this;
                uni.showLoading({
                    title: "图片加载中...",
                });
 
                /* 获取图片信息  */
                uni.getImageInfo({
                    src: _this.imageSrc,
                    success: function success(res) {
                        let imgH = res.height;
                        let imgW = res.width;
 
                        // let IMG_SCR_H_R = SCREEN_HEIGHT / imgH;
                        // let IMG_SCR_W_R = SCREEN_WIDTH / imgW;
 
                        /* 图片的宽高比  */
                        IMG_RATIO = imgW / imgH;
 
                        /**
                         * 如果图片更高一些,为确保图片能够完整在视窗内显示需如下处理
                         * 1. 缩放图片的高为 视窗高度减去底部菜单按钮高度(120)
                         * 2. 根据图片缩放后的高度,根据图片宽高比计算图片的宽度
                         * 3. 如果步骤2计算的图片宽度大于屏幕宽度,则需要再次调整图片宽度为视窗宽度-margin(10)
                         * 4. 根据步骤3的宽度,结合图片宽高比重新计算图片的高度
                         */
                        if (IMG_RATIO < 1 && (SCREEN_HEIGHT - 120) * IMG_RATIO < SCREEN_WIDTH - 10) {
                            IMG_REAL_W = (SCREEN_HEIGHT - 120) * IMG_RATIO;
                            IMG_REAL_H = SCREEN_HEIGHT - 120;
                        } else {
                            IMG_REAL_W = SCREEN_WIDTH - 10;
                            IMG_REAL_H = IMG_REAL_W / IMG_RATIO;
                        }
 
                        /* 初始化裁剪区域的位置和形状  */
                        let [cutT, cutB, cutL, cutR] = _this.initCutArea(IMG_RATIO, IMG_REAL_H,
                        IMG_REAL_W);
 
                        _this.setData({
                            /* 裁剪区域的宽高同图片尺寸  */
                            cropperW: IMG_REAL_W,
                            cropperH: IMG_REAL_H,
 
                            /* 上下左右各留一定的margin已便更好的拖动裁剪区域  */
                            cropperL: Math.ceil((SCREEN_WIDTH - IMG_REAL_W) / 2),
 
                            /* 留出底部操作按钮位置 70  */
                            cropperT: Math.ceil((SCREEN_HEIGHT - IMG_REAL_H - 90) / 2),
                            cutL: cutL,
                            cutT: cutT,
                            cutR: cutR,
                            cutB: cutB,
                            // 图片缩放值
                            imageW: IMG_REAL_W,
                            imageH: IMG_REAL_H,
                            scaleP: IMG_REAL_W / SCREEN_WIDTH,
                            qualityWidth: DRAW_IMAGE_W,
                            innerAspectRadio: IMG_RATIO,
                        });
                        _this.setData({
                            isShowImg: true,
                        });
                        uni.hideLoading();
                    },
                });
            },
 
            initCutArea(IMG_RATIO, IMG_REAL_H, IMG_REAL_W) {
                let _this = this;
                /* 自由裁剪裁剪区域默认覆盖整个图片  */
                let cutT = 0;
                let cutB = 0;
                let cutL = 0;
                let cutR = 0;
 
                /* 正方形裁剪,初始化裁剪区域为正方形并居中  */
                if (_this.cropperType == "fixed") {
                    if (IMG_RATIO < 1) {
                        /* 图片比较高  */
                        cutT = (IMG_REAL_H - IMG_REAL_W) / 2;
                        cutB = (IMG_REAL_H - IMG_REAL_W) / 2;
                    } else {
                        /* 图片比较宽  */
                        cutL = (IMG_REAL_W - IMG_REAL_H) / 2;
                        cutR = (IMG_REAL_W - IMG_REAL_H) / 2;
                    }
                }
 
                /* 固定比例裁剪,初始化裁剪区域比例和设定值相同  */
                if (_this.cropperType == "ratio") {
                    let ratio = +_this.ratio;
                    if (IMG_RATIO < 1) {
                        /* 图片比较高  */
                        if (IMG_REAL_W / ratio > IMG_REAL_H) {
                            cutT = cutB = 0;
                            cutL = cutR = (IMG_REAL_W - IMG_REAL_H * ratio) / 2;
                        } else {
                            cutR = cutL = 0;
                            cutT = cutB = (IMG_REAL_H - IMG_REAL_W / ratio) / 2;
                        }
                    } else {
                        /* 图片比较宽  */
                        if (IMG_REAL_H * ratio > IMG_REAL_W) {
                            cutL = cutR = 0;
                            cutB = cutT = (IMG_REAL_H - IMG_REAL_W / ratio) / 2;
                        } else {
                            cutT = cutB = 0;
                            cutL = cutR = (IMG_REAL_W - IMG_REAL_H * ratio) / 2;
                        }
                    }
                }
 
                return [cutT, cutB, cutL, cutR];
            },
            // 拖动时候触发的touchStart事件
            contentStartMove(e) {
                PAGE_X = e.touches[0].pageX;
                PAGE_Y = e.touches[0].pageY;
            },
            // 拖动时候触发的touchMove事件
            contentMoveing(e) {
                var _this = this;
                var dragLengthX = (PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO;
                var dragLengthY = (PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO;
                // 左移
                if (dragLengthX > 0) {
                    if (this.cutL - dragLengthX < 0) dragLengthX = this.cutL;
                } else {
                    if (this.cutR + dragLengthX < 0) dragLengthX = -this.cutR;
                }
                if (dragLengthY > 0) {
                    if (this.cutT - dragLengthY < 0) dragLengthY = this.cutT;
                } else {
                    if (this.cutB + dragLengthY < 0) dragLengthY = -this.cutB;
                }
                this.setData({
                    cutL: this.cutL - dragLengthX,
                    cutT: this.cutT - dragLengthY,
                    cutR: this.cutR + dragLengthX,
                    cutB: this.cutB + dragLengthY,
                });
                PAGE_X = e.touches[0].pageX;
                PAGE_Y = e.touches[0].pageY;
            },
            contentTouchEnd() {},
 
            // 获取图片尺寸信息
            previewImg() {
                try {
                    var _this = this;
                    uni.showLoading({
                        title: "图片生成中...",
                    });
                    // 将图片写入画布
                    const ctx = uni.createCanvasContext("myCanvas", _this);
                    ctx.drawImage(_this.imageSrc, 0, 0, IMG_REAL_W, IMG_REAL_H);
                    ctx.draw(true, () => {
                        // 获取画布要裁剪的位置和宽度   均为百分比 * 画布中图片的宽度    保证了在微信小程序中裁剪的图片模糊  位置不对的问题 canvasT = (_this.cutT / _this.cropperH) * (_this.imageH / pixelRatio)
                        var canvasW = ((_this.cropperW - _this.cutL - _this.cutR) / _this.cropperW) * IMG_REAL_W;
                        var canvasH = ((_this.cropperH - _this.cutT - _this.cutB) / _this.cropperH) * IMG_REAL_H;
                        var canvasL = (_this.cutL / _this.cropperW) * IMG_REAL_W;
                        var canvasT = (_this.cutT / _this.cropperH) * IMG_REAL_H;
                        uni.canvasToTempFilePath({
                                x: canvasL,
                                y: canvasT,
                                width: canvasW,
                                height: canvasH,
                                // destWidth: canvasW,
                                // destHeight: canvasH,
                                quality: +this.quality,
                                fileType: this.fileType,
                                canvasId: "myCanvas",
                                success: function(res) {
                                    uni.hideLoading();
                                    // 成功获得地址的地方
                                    uni.previewImage({
                                        current: "", // 当前显示图片的http链接
                                        urls: [res.tempFilePath], // 需要预览的图片http链接列表
                                    });
                                },
                                fail: function(err) {
                                    uni.hideLoading();
                                    uni.showToast({
                                        title: "图片截取失败!",
                                        icon: "none",
                                    });
                                },
                            },
                            _this
                        );
                    });
                } catch (e) {}
            },
 
            /* 完成裁剪,输出裁剪后的图片路径  */
            finish: function() {
                var _this = this;
                uni.showLoading({
                    title: "图片生成中...",
                });
                // 将图片写入画布
                const ctx = uni.createCanvasContext("myCanvas", _this);
                ctx.drawImage(_this.imageSrc, 0, 0, IMG_REAL_W, IMG_REAL_H);
                ctx.draw(true, () => {
                    // 获取画布要裁剪的位置和宽度   均为百分比 * 画布中图片的宽度    保证了在微信小程序中裁剪的图片模糊  位置不对的问题 canvasT = (_this.cutT / _this.cropperH) * (_this.imageH / pixelRatio)
                    var canvasW = ((_this.cropperW - _this.cutL - _this.cutR) / _this.cropperW) * IMG_REAL_W;
                    var canvasH = ((_this.cropperH - _this.cutT - _this.cutB) / _this.cropperH) * IMG_REAL_H;
                    var canvasL = (_this.cutL / _this.cropperW) * IMG_REAL_W;
                    var canvasT = (_this.cutT / _this.cropperH) * IMG_REAL_H;
                    uni.canvasToTempFilePath({
                            x: canvasL,
                            y: canvasT,
                            width: canvasW,
                            height: canvasH,
                            // destWidth: canvasW,
                            // destHeight: canvasH,
                            quality: +this.quality,
                            fileType: this.fileType,
                            canvasId: "myCanvas",
                            success: function(res) {
                                uni.hideLoading();
                                // 成功获得地址的地方
                                _this.$emit("getImg", res.tempFilePath);
                                _this.isShow = false;
                            },
                            fail: function(err) {
                                uni.hideLoading();
                                uni.showToast({
                                    title: "图片截取失败!",
                                    icon: "none",
                                });
                            },
                        },
                        _this
                    );
                });
            },
 
            // 设置大小的时候触发的touchStart事件
            dragStart(e) {
                T_PAGE_X = e.touches[0].pageX;
                T_PAGE_Y = e.touches[0].pageY;
                CUT_L = this.cutL;
                CUT_R = this.cutR;
                CUT_B = this.cutB;
                CUT_T = this.cutT;
            },
 
            // 设置大小的时候触发的touchMove事件
            dragMove(e) {
                // this.cropperType == "fixed" ? this.fixedScaleDrag(e) : this.freeDrag(e);
                this[this.cropperType + "Drag"](e);
            },
 
            /* 固定比例(正方形)截取 ,只有右下角裁剪滑动拖动有效*/
            fixedDrag(e) {
                var _this = this;
                var dragType = e.target.dataset.drag;
                switch (dragType) {
                    case "rightBottom":
                        var dragLengthX = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO;
                        // var dragLengthY = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO;
                        // if (CUT_B + dragLengthY < 0) dragLengthY = -CUT_B;
 
                        if (CUT_R + dragLengthX < 0) dragLengthX = -CUT_R;
 
                        /* 右侧和底部同比变化 */
                        let cutB = CUT_B + dragLengthX;
                        let cutR = CUT_R + dragLengthX;
 
                        /* 越界判断  */
                        if (_this.cutB == 0 && cutB < 0) return;
                        if (_this.cutR == 0 && cutR < 0) return;
 
                        (_this.cutB > 0 || CUT_B == 0) &&
                        this.setData({
                            cutB: cutB < 0 ? 0 : cutB,
                            cutR: cutR,
                        });
                        break;
                    default:
                        break;
                }
            },
 
            /* 等比例截图,只能通过右下角的滑块改变截图区域  */
            ratioDrag(e) {
                var _this = this;
                var dragType = e.target.dataset.drag;
                switch (dragType) {
                    case "rightBottom":
                        var dragLengthX = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO;
                        // var dragLengthY = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO;
                        // if (CUT_B + dragLengthY < 0) dragLengthY = -CUT_B;
 
                        if (CUT_R + dragLengthX < 0) dragLengthX = -CUT_R;
 
                        /* 右侧和底部同比变化 */
                        let cutB = CUT_B + dragLengthX / _this.ratio;
                        let cutR = CUT_R + dragLengthX;
 
                        /* 越界判断  */
                        if (_this.cutB == 0 && cutB < 0) return;
                        if (_this.cutR == 0 && cutR < 0) return;
 
                        (_this.cutB > 0 || CUT_B == 0) &&
                        this.setData({
                            cutB: cutB < 0 ? 0 : cutB,
                            cutR: cutR,
                        });
                        break;
                    default:
                        break;
                }
            },
 
            /* 自由截取,整个裁剪边框均能拖动  */
            freeDrag(e) {
                var _this = this;
                var dragType = e.target.dataset.drag;
                switch (dragType) {
                    case "right":
                        var dragLength = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO;
                        if (CUT_R + dragLength < 0) dragLength = -CUT_R;
                        this.setData({
                            cutR: CUT_R + dragLength,
                        });
                        break;
                    case "left":
                        var dragLength = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO;
                        if (CUT_L - dragLength < 0) dragLength = CUT_L;
                        if (CUT_L - dragLength > this.cropperW - this.cutR)
                            dragLength = CUT_L - (this.cropperW - this.cutR);
                        this.setData({
                            cutL: CUT_L - dragLength,
                        });
                        break;
                    case "top":
                        var dragLength = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO;
                        if (CUT_T - dragLength < 0) dragLength = CUT_T;
                        if (CUT_T - dragLength > this.cropperH - this.cutB)
                            dragLength = CUT_T - (this.cropperH - this.cutB);
                        this.setData({
                            cutT: CUT_T - dragLength,
                        });
                        break;
                    case "bottom":
                        var dragLength = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO;
                        if (CUT_B + dragLength < 0) dragLength = -CUT_B;
                        this.setData({
                            cutB: CUT_B + dragLength,
                        });
                        break;
                    case "rightBottom":
                        var dragLengthX = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO;
                        var dragLengthY = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO;
                        if (CUT_B + dragLengthY < 0) dragLengthY = -CUT_B;
                        if (CUT_R + dragLengthX < 0) dragLengthX = -CUT_R;
                        let cutB = CUT_B + dragLengthY;
                        let cutR = CUT_R + dragLengthX;
                        this.setData({
                            cutB: cutB,
                            cutR: cutR,
                        });
                        break;
                    default:
                        break;
                }
            },
        },
    };
</script>
 
<style>
    /* pages/uni-cropper/index.wxss */
    .container {
        background-color: #fff;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 50px;
        display: block;
        align-items: center;
        flex-direction: column;
        z-index: 998;
        height: 100vh;
    }
 
    .cropper-config {
        position: fixed;
        z-index: 999;
        bottom: 60px;
        left: 0;
        right: 0;
 
        width: 90%;
        margin: 0 auto;
        /* padding: 20upx 40upx; */
    }
 
    .button-box {
        display: flex;
        flex-direction: row;
        justify-content: space-between;
 
        width: 100%;
    }
 
    .button-box button {
        width: 25%;
        line-height: 35px;
        height: 35px;
    }
 
    .cropper-content {
        width: 100%;
        min-height: 750upx;
    }
 
    .uni-corpper {
        position: relative;
 
        overflow: hidden;
 
        box-sizing: border-box;
        margin: 0 auto;
 
        -webkit-user-select: none;
        -moz-user-select: none;
        -ms-user-select: none;
        user-select: none;
 
        -webkit-tap-highlight-color: transparent;
        -webkit-touch-callout: none;
    }
 
    .uni-corpper-content {
        position: relative;
    }
 
    .uni-corpper-content image {
        display: block;
 
        width: 100%;
        min-width: 0 !important;
        max-width: none !important;
        /* height: 100%; */
        min-height: 0 !important;
        /* max-height: none !important; */
 
        max-height: calc(100vh - 100upx);
        margin: 0 auto;
 
        image-orientation: 0deg !important;
    }
 
    /* 移动图片效果 */
    .uni-cropper-drag-box {
        position: absolute;
        z-index: 1;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
 
        cursor: move;
 
        background: rgba(0, 0, 0, 0.479);
    }
 
    /* 内部的信息 */
    .uni-corpper-crop-box {
        position: absolute;
        z-index: 2;
        max-height: calc(100vh - 100upx);
        background: rgba(56, 50, 50, 0.479);
    }
 
    .uni-corpper-crop-box .uni-cropper-view-box {
        position: relative;
 
        display: block;
        overflow: visible;
 
        width: 100%;
        height: 100%;
 
        max-height: calc(100vh - 100upx);
        outline: 5upx solid rgb(100, 97, 97);
        outline-color: rgba(255, 255 255, 1);
    }
 
    /* 横向虚线 */
    .uni-cropper-dashed-h {
        position: absolute;
        top: 33.33333333%;
        left: 0;
 
        width: 100%;
        height: 33.33333333%;
 
        border-top: 1upx dashed rgba(255, 255, 255, 0.5);
        border-bottom: 1upx dashed rgba(255, 255, 255, 0.5);
    }
 
    /* 纵向虚线 */
    .uni-cropper-dashed-v {
        position: absolute;
        top: 0;
        left: 33.33333333%;
 
        width: 33.33333333%;
        height: 100%;
 
        border-right: 1upx dashed rgba(255, 255, 255, 0.5);
        border-left: 1upx dashed rgba(255, 255, 255, 0.5);
    }
 
    /* 四个方向的线  为了之后的拖动事件*/
    .uni-cropper-line-t {
        position: absolute;
        top: 0;
        left: 0;
 
        display: block;
 
        width: 100%;
        height: 3upx;
 
        cursor: n-resize;
 
        opacity: 0.1;
        background-color: white;
    }
 
    .uni-cropper-line-t::before {
        position: absolute;
        z-index: 11;
        top: 50%;
        right: 0upx;
        bottom: 0;
 
        width: 100%;
        height: 41upx;
 
        content: "";
        -webkit-transform: translate3d(0, -50%, 0);
        transform: translate3d(0, -50%, 0);
 
        background: transparent;
    }
 
    .uni-cropper-line-r {
        position: absolute;
        top: 0;
        right: 0upx;
 
        display: block;
 
        width: 3upx;
        height: 100%;
 
        cursor: e-resize;
 
        opacity: 0.1;
        background-color: white;
    }
 
    .uni-cropper-line-r::before {
        position: absolute;
        z-index: 11;
        top: 0;
        bottom: 0;
        left: 50%;
 
        width: 41upx;
        height: 100%;
 
        content: "";
        -webkit-transform: translate3d(-50%, 0, 0);
        transform: translate3d(-50%, 0, 0);
 
        background: transparent;
    }
 
    .uni-cropper-line-b {
        position: absolute;
        bottom: 0;
        left: 0;
 
        display: block;
 
        width: 100%;
        height: 3upx;
 
        cursor: s-resize;
 
        opacity: 0.1;
        background-color: white;
    }
 
    .uni-cropper-line-b::before {
        position: absolute;
        z-index: 11;
        top: 50%;
        right: 0upx;
        bottom: 0;
 
        width: 100%;
        height: 41upx;
 
        content: "";
        -webkit-transform: translate3d(0, -50%, 0);
        transform: translate3d(0, -50%, 0);
 
        background: transparent;
    }
 
    .uni-cropper-line-l {
        position: absolute;
        top: 0;
        left: 0;
 
        display: block;
 
        width: 3upx;
        height: 100%;
 
        cursor: w-resize;
 
        opacity: 0.1;
        background-color: white;
    }
 
    .uni-cropper-line-l::before {
        position: absolute;
        z-index: 11;
        top: 0;
        bottom: 0;
        left: 50%;
 
        width: 41upx;
        height: 100%;
 
        content: "";
        -webkit-transform: translate3d(-50%, 0, 0);
        transform: translate3d(-50%, 0, 0);
 
        background: transparent;
    }
 
    .uni-cropper-point {
        position: absolute;
        z-index: 3;
 
        width: 5upx;
        height: 5upx;
 
        opacity: 0.75;
        background-color: rgb(145, 132, 132);
    }
 
    .point-t {
        top: -3upx;
        left: 50%;
 
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    .point-tr {
        top: -3upx;
        left: 100%;
 
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    .point-r {
        top: 50%;
        left: 100%;
 
        margin-top: -3upx;
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    .point-rb {
        position: absolute;
        z-index: 1112;
        top: 100%;
        left: 100%;
 
        width: 36upx;
        height: 36upx;
 
        cursor: n-resize;
        -webkit-transform: translate3d(-50%, -50%, 0);
        transform: translate3d(-50%, -50%, 0);
 
        opacity: 1;
        background-color: rgb(231, 222, 222);
    }
 
    .point-b {
        top: 100%;
        left: 50%;
 
        margin-top: -3upx;
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    .point-bl {
        top: 100%;
        left: 0;
 
        margin-top: -3upx;
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    .point-l {
        top: 50%;
        left: 0;
 
        margin-top: -3upx;
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    .point-lt {
        top: 0;
        left: 0;
 
        margin-top: -3upx;
        margin-left: -3upx;
 
        cursor: n-resize;
    }
 
    /* 裁剪框预览内容 */
    .uni-cropper-viewer {
        position: relative;
 
        overflow: hidden;
 
        width: 100%;
        height: 100%;
    }
 
    .uni-cropper-viewer image {
        position: absolute;
        z-index: 2;
    }
</style>

 

标签:REAL,uniapp,canvas,CUT,cutB,IMG,头像,cutR,uni
来源: https://www.cnblogs.com/LindaBlog/p/16612920.html