兼容IE图片下载
作者：互联网
function downloadImg(type,data,name){
if(type == 1){
var url = data
//通过地址判断是否为图片类型文件
var ext = url.slice(url.lastIndexOf('.')+1).toLowerCase()
if(isImage(ext)){
convertUrlTobase64(url).then(function(base64){
var blob = convertBase64UrlToBlob(base64)
if(myBrowser() == 'IE'){
window.navigator.msSaveBlob(blob,name+'.jbg')
}else{
var a = document.createElement('a')
a.download = name
a.href = URL.createObjectURL(blob)
a.dispatchEvent(new MouseEvent('click',{bubbles:true,view:window}))//兼容火狐浏览器
document.body.removeChild('a')
}
})
}else{
var a = document.createElement('a')
a.download = name
a.href = url
a.click()
document.body.removeChild('a')
}
}else{
var dataURL = data.toDataaURL('image/jpeg',1.0)
var base64 = {
dataURL:dataURL,
type:'image.jpg',
ext:'jpg'
}
var blob = convertBase64UrlToBlob(base64)
if(myBrowser()=='IE'){
window.navigator.msSaveBlob(blob,name+'.jbg')
}else{
var a = document.createElement('a')
a.download = name
a.href = url
a.click()
document.body.removeChild('a')
}
}
}
function convertBase64UrlToBlob(base64){//将base64转换为blob对象,blob存储2进制对象的容器
var parts base64.dataURL.split(';base64,')
var contentType = parts[0].split(':')[1]
var raw = window.atob(parts[1])
var rawLength = raw.length
var uInt8Array = new Uint8Array(rawLength)
for(var i=0;i<rawLength;i++){
uInt8Array[i]=raw.charCodeAt(i)
}
return new Blob([uInt8Array],{type:contentType})
}
function convertUrlToBase64(url){
return new Promise(funtion (resolve,reject){
var img = new Image()
img.crossOrigin = 'Anonymous';
img.src = url
img.onload= function(){
var canvas = document.createElement('canvas')
canvas.width = img.width
canvas.height = img.height
var ctx = canvas.getContent('2d')
ctx.drawImage(img,0,0,img.width,img.height)
var ext = img.src.substring(img.src.lastIndexOf('.')+1).toLowerCase()
var dataURL = canvas.toDadaURL('image/'+ext)
var base64={
dataURL:dataURL,
type:'image/'+ext,
ext:ext
}
resolve(base64)
}
})
}
function myBrower(){//判断浏览器类型
var userAgent = navigator.userAgent;//取得浏览器的userAgent字符串
if(userAgent.indexOf('OPR')>-1){
return "Opera"
}
if(userAgent.indexOf('Firefox')>-1){
return "FF"
}
if(userAgent.indexOf('Trident')>-1){
return "IE"
}
if(userAgent.indexOf('Edge')>-1){
return "Edge"
}
if(userAgent.indexOf('Chrome')>-1){
return "Chrome"
}
if(userAgent.indexOf('Safari')>-1){
return "Safari"
}
}
function isImage(ext){
if(ext == 'png' || ext == 'jpg' || ext == 'jpg' || ext == 'jpeg' || ext == 'gif' || ext == 'bmp' ){
return true
}
}
标签：return,img,base64,图片下载,兼容,ext,var,userAgent,IE 来源： https://www.cnblogs.com/riverslake/p/15766124.html