工作用到了，就在这里记录一下
<template>
<div>
<h2 class="title-detail">图片描述</h2>
<input type="hidden" id="picIndex" value="0" />
<div id="image-list" class="row image-list">
<!-- <input id="upload_image" type="file" name="image" accept="image/*" /> -->
</div>拍照：
<input type="file" id="upload" accept="image/jpg" @change="upload" />
<ul>
<li v-for="(item,index) in imgList" :key="index">
<img
:src="item"
alt
style="width:100px;height:100px;border:1px solid #ccc;display: inline-block;"
/>
<div class="delimg el-icon-circle-close" @click="delimg(index)"></div>
</li>
</ul>
<img src="./../../assets/timg.png" id="my-img" />
</div>
</template>
<script>
import $ from "jquery";
import Exif from "exif-js";
import { stringify } from "querystring";
export default {
data() {
return {
headerImage: "",
picValue: "",
imgList: []
};
},
created() {},
mounted() {
$(document).ready(function() {
$("#my-img").click(function() {
$("#upload").click();
});
});
},
methods: {
upload(e) {
let files = e.target.files || e.dataTransfer.files;
if (!files.length) return;
this.picValue = files[0];
this.imgPreview(this.picValue);
},
imgPreview(file) {
let self = this;
let Orientation;
//去获取拍照时的信息，解决拍出来的照片旋转问题
Exif.getData(file, function() {
Orientation = Exif.getTag(this, "Orientation");
});
// 看支持不支持FileReader
if (!file || !window.FileReader) return;
if (/^image/.test(file.type)) {
// 创建一个reader
let reader = new FileReader();
// 将图片2将转成 base64 格式
reader.readAsDataURL(file);
// 读取成功后的回调
reader.onloadend = function() {
let result = this.result;
let img = new Image();
img.src = result;
//判断图片是否大于100K,是就直接上传，反之压缩图片
// if (this.result.length <= (100 * 1024)) {
// self.headerImage = this.result;
// self.postImg();
// }else {
img.onload = function() {
let data = self.compress(img, Orientation);
self.headerImage = data;
if (self.imgList.length < 9) {
self.imgList.push(self.headerImage);
console.log(self.imgList, "list");
} else {
alert("上传照片不得大于9张");
}
self.postImg(self.picValue);
};
// }
};
}
},
postImg(file) {
// 这里写接口
console.log(file,'file');
this.$apiFetch.update('web.oss.upload',{ file:file}).then((data) => {
console.log(data,'adta')
}).catch((err) => {
console.log(err)
})
},
rotateImg(img, direction, canvas) {
//最小与最大旋转方向，图片旋转4次后回到原方向
const min_step = 0;
const max_step = 3;
if (img == null) return;
//img的高度和宽度不能在img元素隐藏后获取，否则会出错
let height = img.height;
let width = img.width;
let step = 2;
if (step == null) {
step = min_step;
}
if (direction == "right") {
step++;
//旋转到原位置，即超过最大值
step > max_step && (step = min_step);
} else {
step--;
step < min_step && (step = max_step);
}
//旋转角度以弧度值为参数
let degree = (step * 90 * Math.PI) / 180;
let ctx = canvas.getContext("2d");
switch (step) {
case 0:
canvas.width = width;
canvas.height = height;
ctx.drawImage(img, 0, 0);
break;
case 1:
canvas.width = height;
canvas.height = width;
ctx.rotate(degree);
ctx.drawImage(img, 0, -height);
break;
case 2:
canvas.width = width;
canvas.height = height;
ctx.rotate(degree);
ctx.drawImage(img, -width, -height);
break;
case 3:
canvas.width = height;
canvas.height = width;
ctx.rotate(degree);
ctx.drawImage(img, -width, 0);
break;
}
},
compress(img, Orientation) {
let canvas = document.createElement("canvas");
let ctx = canvas.getContext("2d");
//瓦片canvas
let tCanvas = document.createElement("canvas");
let tctx = tCanvas.getContext("2d");
let initSize = img.src.length;
let width = img.width;
let height = img.height;
//如果图片大于四百万像素，计算压缩比并将大小压至400万以下
let ratio;
if ((ratio = (width * height) / 4000000) > 1) {
console.log("大于400万像素");
ratio = Math.sqrt(ratio);
width /= ratio;
height /= ratio;
} else {
ratio = 1;
}
canvas.width = width;
canvas.height = height;
// 铺底色
ctx.fillStyle = "#fff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
//如果图片像素大于100万则使用瓦片绘制
let count;
if ((count = (width * height) / 1000000) > 1) {
console.log("超过100W像素");
count = ~~(Math.sqrt(count) + 1); //计算要分成多少块瓦片
// 计算每块瓦片的宽和高
let nw = ~~(width / count);
let nh = ~~(height / count);
tCanvas.width = nw;
tCanvas.height = nh;
for (let i = 0; i < count; i++) {
for (let j = 0; j < count; j++) {
tctx.drawImage(
img,
i * nw * ratio,
j * nh * ratio,
nw * ratio,
nh * ratio,
0,
0,
nw,
nh
);
ctx.drawImage(tCanvas, i * nw, j * nh, nw, nh);
}
}
} else {
ctx.drawImage(img, 0, 0, width, height);
}
//修复ios上传图片的时候 被旋转的问题
if (Orientation != "" && Orientation != 1) {
switch (Orientation) {
case 6: //需要顺时针（向左）90度旋转
this.rotateImg(img, "left", canvas);
break;
case 8: //需要逆时针（向右）90度旋转
this.rotateImg(img, "right", canvas);
break;
case 3: //需要180度旋转
this.rotateImg(img, "right", canvas); //转两次
this.rotateImg(img, "right", canvas);
break;
}
}
//进行最小压缩
let ndata = canvas.toDataURL("image/jpeg", 0.1);
console.log("压缩前：" + initSize);
console.log("压缩后：" + ndata.length);
console.log(
"压缩率：" + ~~((100 * (initSize - ndata.length)) / initSize) + "%"
);
tCanvas.width = tCanvas.height = canvas.width = canvas.height = 0;
return ndata;
},
delimg(index) {
for (let i = 0; i < this.imgList.length; i++) {
if (i == index) {
this.imgList.splice(index, 1); //删除第index个元素
}
}
console.log(this.imgList, "imgList2del");
}
}
};
</script>
<style lang="less" scope>
* {
margin: 0;
padding: 0;
}
#upload {
display: none;
}
.show {
width: 100px;
height: 100px;
overflow: hidden;
position: relative;
border-radius: 50%;
border: 1px solid #d5d5d5;
}
.picture {
width: 100%;
height: 100%;
overflow: hidden;
background-position: center center;
background-repeat: no-repeat;
background-size: cover;
}
ul > li {
width: 120px;
padding: 5px;
display: inline-block;
position: relative;
.delimg {
width: 5px;
height: 5px;
position: absolute;
top: 0;
right: 10px;
}
}
#my-img {
width: 5rem;
}
</style>
