LVGL学习之路——模拟器实现简易计算器
作者：互联网
#include "../../lv_examples.h"
#include "test.h"
#include <Windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define MAX_NUM 10 // 设置文本框显示最大位数
static lv_obj_t* ta; // 文本框对象
static lv_obj_t* btnm1; // 按钮对象
static char result[MAX_NUM]; // 缓存结果
static double save_num(char* num) // 将字符串保存成浮点数
{
return atof(num);
}
static char judge_num(double num) // 比较数字尾数有没有超过指定数目
{
char n[100];
sprintf(n,"%g", num);
printf("%d",strlen(n));
if (strlen(n)<MAX_NUM)
{
return 0;
}
else
{
return 1;
}
}
static void calculate(double before, double now, char operate, char* num) // 计算浮点数
{
double result = now;
switch (operate)
{
case '+':
result = before + now;
break;
case '-':
result = before - now;
break;
case '*':
result = before * now;
break;
case '/':
result = before / now;
break;
default:
break;
}
printf("result:%llf\n",result);
sprintf(num, "%g", result);
}
static void event_handler(lv_obj_t* obj, lv_event_t event)
{
if (event == LV_EVENT_VALUE_CHANGED) {
static char error = 0;
static double before = 0;
volatile double now = 0;
static char operate = '\0';
static char num[MAX_NUM];
const char* txt = lv_btnmatrix_get_active_btn_text(obj); // 获取按键值
if (error == 0)
{
switch (txt[0])
{
case '=':
if (judge_num(before) == 0)
{
now = save_num(num);
calculate(before,now,operate,num);
operate = '\0';
before = save_num(num);
}
else
{
error = 1;
lv_textarea_set_text(ta, "EOR");
printf("error\n");
}
break;
case 'D':
num[strlen(num) - 1] = '\0';
break;
case '+':
now = save_num(num);
if (operate != '\0')
{
calculate(before, now, operate, num);
before = save_num(num);;
}
else
{
before = now;
}
operate = '+';
memset(num, 0, MAX_NUM);
break;
case '-':
now = save_num(num);
if (operate != '\0')
{
calculate(before, now, operate, num);
before = save_num(num);;
}
else
{
before = now;
}
operate = '-';
memset(num, 0, MAX_NUM);
break;
case '*':
now = save_num(num);
if (operate != '\0')
{
calculate(before, now, operate, num);
before = save_num(num);;
}
else
{
before = now;
}
memset(num, 0, MAX_NUM);
operate = '*';
break;
case '/':
now = save_num(num);
if (operate != '\0')
{
calculate(before, now, operate, num);
before = save_num(num);;
}
else
{
before = now;
}
memset(num, 0, MAX_NUM);
operate = '/';
break;
case ' ':
break;
default:
if (strlen(num) < MAX_NUM)
{
num[strlen(num)] = txt[0];
}
break;
}
}
if (txt[0] == 'C')
{
memset(num, 0, MAX_NUM);
memset(result, 0, MAX_NUM);
before = 0;
now = 0;
error = 0;
operate = '\0';
}
lv_textarea_set_text(ta, num);
printf("before:%llf,now:%llf\n", before, now);
}
}
static void ta_event_cb(lv_obj_t* ta, lv_event_t event)
{
if (event == LV_EVENT_VALUE_CHANGED) {
const char* txt = lv_textarea_get_text(ta);
}
}
static const char* btnm_map[] = { "C", "D", "/", "\n",
"1", "2", "3", "+", "\n",
"4", "5", "6", "-", "\n",
"7", "8", "9", "*", "\n",
".", "0","=", "" };
static void lv_ex_btnmatrix_1(void)
{
btnm1 = lv_btnmatrix_create(lv_scr_act(), NULL); // 生成矩阵(默认5个)按钮
lv_btnmatrix_set_map(btnm1, btnm_map); // 按照数组生成排列按钮
lv_btnmatrix_set_btn_width(btnm1, 17, 2); // 设置第11个按钮的比重为2（默认为1）这将导致矩阵按键重绘
lv_btnmatrix_set_btn_width(btnm1, 0, 3);
lv_btnmatrix_set_btn_width(btnm1, 1, 3);
lv_btnmatrix_set_btn_width(btnm1, 2, 2);
lv_btnmatrix_set_btn_ctrl(btnm1, 17, LV_BTNMATRIX_CTRL_CHECK_STATE);// 设置按钮矩阵的按钮属性（变成选中状态）
lv_obj_set_event_cb(btnm1, event_handler); // 设置按钮回调函数
lv_obj_set_size(btnm1, LV_HOR_RES, LV_VER_RES * 6 / 7); // 先调整
lv_obj_align(btnm1, NULL, LV_ALIGN_IN_BOTTOM_LEFT, 0, 0); // 再移动
}
static void lv_ex_textarea_3(void)
{
/* Create the text area */
ta = lv_textarea_create(lv_scr_act(), NULL); // 生成文本框控件
lv_obj_set_event_cb(ta, ta_event_cb); // 设置文本框回调函数
lv_textarea_set_accepted_chars(ta, "0123456789+-.*/EOR"); // 设置文本框允许被输入的数字
lv_textarea_set_max_length(ta, MAX_NUM); // 设置文本框允许最大储存的数字
lv_textarea_set_one_line(ta, true); // 设置文本框成单行
lv_textarea_set_text(ta, ""); // 设置文本框文字
lv_textarea_set_edge_flash(ta, true); // 设置溢出提示
lv_obj_set_size(ta, LV_HOR_RES, LV_VER_RES / 7); // 先调整
lv_obj_align(ta, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 0); // 再移动
static lv_style_t my_style;
lv_style_init(&my_style);
lv_style_set_text_color(&my_style, LV_STATE_DEFAULT, LV_COLOR_BLACK);
lv_style_set_text_font(&my_style, LV_STATE_DEFAULT, &lv_font_montserrat_48);
lv_obj_add_style(ta, LV_OBJ_PART_MAIN, &my_style);
}
void test(void)
{
lv_ex_btnmatrix_1();
lv_ex_textarea_3();
}
标签：now,set,模拟器,lv,operate,num,计算器,LVGL,before 来源： https://blog.csdn.net/qq_42679566/article/details/110070684