前段时间做微信公众号Vue项目的时候，要用到图片裁剪功能，但是上网找的好几个vue插件在ios端都会出现问题, 但是这个完美兼容ios与安卓，可以放心使用。
是由 https://www.jianshu.com/p/82dbf309f9b1?from=groupmessage 这个修改而来的，已经修改成了在单独的组件可以用了，详情请看前面的链接。
修改后的组件完整代码如下：
<template>
<div class="vue-box">
<img :src="imgUrl" alt="" id="img">
<input type="file" class="file" accept="image/png,image/jpg,image/jpeg" @change="change($event)">
</div>
</template>
<script>
import Cropper from 'cropperjs'
import Exif from 'exif-js'
export default {
props: {
// 定义的宽高比
widthRate: {
type: Number,
default: 1,
},
// 定义的宽高比
heightRate: {
type: Number,
default: 1
},
//图片
type: String,
default: function() {
return ''
}
}
},
data() {
return {
}
},
methods: {
change(event) {
let image = document.getElementById('img'); //预览对象
this.clip(event, {
resultObj: image,
aspectWithRatio: Number(this.widthRate),
aspectHeightRatio: Number(this.heightRate)
})
},
//初始化方法
initilize(opt) {
let self = this;
this.options = opt;
//创建dom
this.createElement();
this.resultObj = opt.resultObj;
//初始化裁剪对象
this.cropper = new Cropper(this.preview, {
aspectRatio: opt.aspectWithRatio / opt.aspectHeightRatio,
// aspectRatio: 1/1,
autoCropArea: opt.autoCropArea || 0.8,
viewMode: 2,
guides: true,
cropBoxResizable: true, //是否通过拖动来调整剪裁框的大小
cropBoxMovable: true, //是否通过拖拽来移动剪裁框。
dragCrop: false,
dragMode: "move",//‘crop’: 可以产生一个新的裁剪框3 ‘move’: 只可以移动3 ‘none’: 什么也不处理
center: true,
zoomable: true, //是否允许放大图像。
zoomOnTouch: true,//是否可以通过拖动触摸来放大图像。
scalable: true,
// minCropBoxHeight: 750,
// minCropBoxWidth: 750,
background: false,
checkOrientation: true,
checkCrossOrigin: true,
zoomable: false,
zoomOnWheel: false,
center: false,
toggleDragModeOnDblclick: false,
ready: function() {
// console.log(self.cropper.rotate(90))
if (opt.aspectRatio == 'Free') {
let cropBox = self.cropper.cropBox;
cropBox.querySelector('span.cropper-view-box').style.outline = 'none';
self.cropper.disable();
}
}
});
},
//创建一些必要的DOM，用于图片裁剪
createElement() {
//初始化图片为空对象
this.preview = null;
// <img src="../../assets/app/loading.gif">
let str = '<div><img id="clip_image" src="originUrl"></div><button type="button" id="cancel_clip">取消</button><button type="button" id="clip_button">确定</button>';
str += '<div class="crop_loading"><div class="crop_content"><div class="crop_text">图片修剪中...</div></div></div>';
str += '<div class="crop_success"><div class="crop_success_text">上传成功</div></div></div>';
let body = document.getElementsByTagName('body')[0];
this.reagion = document.createElement('div');
this.reagion.id = 'clip_container';
this.reagion.className = 'container';
this.reagion.innerHTML = str;
//添加创建好的DOM元素
body.appendChild(this.reagion);
this.preview = document.getElementById('clip_image');
//绑定一些方法
this.initFunction();
},
//初始化一些函数绑定
initFunction() {
let self = this;
this.clickBtn = document.getElementById('clip_button');
this.cancelBtn = document.getElementById('cancel_clip');
//确定事件
this.addEvent(this.clickBtn, 'click', function() {
self.crop();
})
//取消事件
this.addEvent(this.cancelBtn, 'click', function() {
self.destoried();
})
//清空input的值
this.addEvent(this.fileObj, 'click', function() {
this.value = '';
})
},
//外部接口，用于input['file']对象change时的调用
clip(e, opt) {
let self = this;
this.fileObj = e.srcElement;
let files = e.target.files || e.dataTransfer.files;
if (!files.length) return false; //不是图片直接返回
//调用初始化方法
this.initilize(opt);
//获取图片文件资源
this.picValue = files[0];
//去获取拍照时的信息，解决拍出来的照片旋转问题
// Exif.getData( files[0] , function(){
// self.Orientation = Exif.getTag( files[0], 'Orientation');
// console.log(self.Orientation)
// });
//调用方法转成url格式
this.originUrl = this.getObjectURL(this.picValue);
//每次替换图片要重新得到新的url
if (this.cropper) {
this.cropper.replace(this.originUrl);
}
},
//图片转码方法
getObjectURL(file) {
let url = null;
if (window.createObjectURL != undefined) { // basic
url = window.createObjectURL(file);
} else if (window.URL != undefined) { // mozilla(firefox)
url = window.URL.createObjectURL(file);
} else if (window.webkitURL != undefined) { // webkit or chrome
url = window.webkitURL.createObjectURL(file);
}
return url;
},
//点击确定进行裁剪
crop() {
let self = this;
let image = new Image();
let croppedCanvas;
let roundedCanvas;
// Crop
document.querySelector('.crop_loading').style.display = 'block';
setTimeout(function() {
croppedCanvas = self.cropper.getCroppedCanvas();
// Round
roundedCanvas = self.getRoundedCanvas(croppedCanvas);
let imgData = roundedCanvas.toDataURL();
image.src = imgData;
//判断图片是否大于100k,不大于直接上传，反之压缩
if (imgData.length < (100 * 1024)) {
self.resultObj.src = imgData;
//图片上传
self.postImg(imgData);
} else {
image.onload = function() {
//压缩处理
let data = self.compress(image, self.Orientation);
self.resultObj.src = data;
//图片上传
self.postImg(data);
}
}
}, 20)
},
//获取裁剪图片资源
getRoundedCanvas(sourceCanvas) {
let canvas = document.createElement('canvas');
let context = canvas.getContext('2d');
let width = sourceCanvas.width;
let height = sourceCanvas.height;
canvas.width = width;
canvas.height = height;
context.imageSmoothingEnabled = true;
context.drawImage(sourceCanvas, 0, 0, width, height);
context.globalCompositeOperation = 'destination-in';
context.beginPath();
context.rect(0, 0, width, height);
context.fill();
return canvas;
},
//销毁原来的对象
destoried() {
let self = this;
//移除事件
this.removeEvent(this.clickBtn, 'click', null);
this.removeEvent(this.cancelBtn, 'click', null);
this.removeEvent(this.fileObj, 'click', null);
//移除裁剪框
this.reagion.parentNode.removeChild(this.reagion);
//销毁裁剪对象
this.cropper.destroy();
this.cropper = null;
},
//图片上传
postImg(imageData) {
// console.log(imageData)
this.$emit('callback', imageData)
//这边写图片的上传
let self = this;
self.destoried();
// window.setTimeout( function () {
// document.querySelector('.crop_loading').style.display = 'none';
// document.querySelector('.crop_success').style.display = 'block';
// //裁剪完后摧毁对象
// self.destoried();
// },3000)
},
//图片旋转
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;
}
},
//图片压缩
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) {
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);
let ndata = canvas.toDataURL('image/png', 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;
},
//添加事件
addEvent(obj, type, fn) {
if (obj.addEventListener) {
obj.addEventListener(type, fn, false);
} else {
obj.attachEvent('on' + type, fn);
}
},
//移除事件
removeEvent(obj, type, fn) {
if (obj.removeEventListener) {
obj.removeEventListener(type, fn, false);
} else {
obj.detachEvent('on' + type, fn);
}
},
}
}
</script>
<style scoped>
.vue-box {
position: relative;
width: 100%;
height: 100%;
min-height: 0.4rem;
}
.vue-box .file {
position: absolute;
width: 100%;
height: 100%;
opacity: 0;
top: 0;
left: 0;
z-index: 99;
cursor: pointer;
}
img {
display: none;
width: 100%;
height: 100%;
}
h3 {
text-align: center;
}
h1,
h2 {
font-weight: normal;
}
ul {
list-style-type: none;
padding: 0;
}
li {
display: inline-block;
margin: 0 10px;
}
a {
color: #42b983;
}
</style>
<style>
#app {
font-family: 'Avenir', Helvetica, Arial, sans-serif;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
text-align: center;
color: #2c3e50;
margin-top: 60px;
}
* {
margin: 0;
padding: 0;
}
#app {
font-family: 'Avenir', Helvetica, Arial, sans-serif;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
box-sizing: border-box;
}
img {
/*display: block;*/
/*margin: 0 auto;*/
}
input[type='file'] {
outline: none;
/*margin-top: 20px;*/
}
* {
margin: 0;
padding: 0;
}
#clip_button {
position: absolute;
right: 10%;
bottom: 20px;
width: 80px;
height: 40px;
border: none;
border-radius: 2px;
background: #1AAD19;
color: #fff;
}
#cancel_clip {
position: absolute;
left: 10%;
bottom: 20px;
width: 80px;
height: 40px;
border: none;
border-radius: 2px;
color: #fff;
background: #E64340;
}
#clip_container.container {
z-index: 99999;
position: fixed;
padding-top: 60px;
left: 0;
top: 0;
right: 0;
bottom: 0;
background: rgba(0, 0, 0, 1);
}
#clip_container.container>div {
position: absolute;
width: 100%;
height: 100%;
top: 50%;
left: 50%;
-webkit-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
#clip_image {
max-width: 100%;
}
.cropper-container {
font-size: 0;
line-height: 0;
position: relative;
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
direction: ltr;
-ms-touch-action: none;
touch-action: none
}
.crop_loading,
.crop_success {
display: none;
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
z-index: 9;
}
.crop_loading .crop_content {
position: absolute;
top: 50%;
left: 50%;
text-align: center;
background: #000;
opacity: 0.9;
height: 66px;
width: 140px;
vertical-align: middle;
color: #fff;
padding-top: 20px;
font-size: 16px;
-webkit-border-radius: 3px;
border-radius: 3px;
-webkit-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.crop_loading .crop_content img {
margin-top: 15px;
margin-bottom: 10px;
}
.crop_success .crop_success_text {
position: absolute;
top: 50%;
left: 50%;
text-align: center;
background: #000;
opacity: 0.9;
width: 120px;
height: 30px;
color: #fff;
line-height: 30px;
font-size: 16px;
-webkit-border-radius: 3px;
border-radius: 3px;
-webkit-transform: translate(-50%, -50%);
transform: translate(-50%, -50%);
}
.cropper-container img {
/* Avoid margin top issue (Occur only when margin-top <= -height) */
display: block;
min-width: 0 !important;
max-width: none !important;
min-height: 0 !important;
max-height: none !important;
width: 100%;
height: 100%;
image-orientation: 0deg
}
.cropper-wrap-box,
.cropper-canvas,
.cropper-drag-box,
.cropper-crop-box,
.cropper-modal {
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
}
.cropper-wrap-box {
overflow: hidden;
}
.cropper-drag-box {
opacity: 0;
background-color: #fff;
}
.cropper-modal {
opacity: .5;
background-color: #000;
}
.cropper-view-box {
display: block;
overflow: hidden;
width: 100%;
height: 100%;
outline: 1px solid #39f;
outline-color: rgba(51, 153, 255, 0.75);
}
.cropper-dashed {
position: absolute;
display: block;
opacity: .5;
border: 0 dashed #eee
}
.cropper-dashed.dashed-h {
top: 33.33333%;
left: 0;
width: 100%;
height: 33.33333%;
border-top-width: 1px;
border-bottom-width: 1px
}
.cropper-dashed.dashed-v {
top: 0;
left: 33.33333%;
width: 33.33333%;
height: 100%;
border-right-width: 1px;
border-left-width: 1px
}
.cropper-center {
position: absolute;
top: 50%;
left: 50%;
display: block;
width: 0;
height: 0;
opacity: .75
}
.cropper-center:before,
.cropper-center:after {
position: absolute;
display: block;
content: ' ';
background-color: #eee
}
.cropper-center:before {
top: 0;
left: -3px;
width: 7px;
height: 1px
}
.cropper-center:after {
top: -3px;
left: 0;
width: 1px;
height: 7px
}
.cropper-face,
.cropper-line,
.cropper-point {
position: absolute;
display: block;
width: 100%;
height: 100%;
opacity: .1;
}
.cropper-face {
top: 0;
left: 0;
background-color: #fff;
}
.cropper-line {
background-color: #39f
}
.cropper-line.line-e {
top: 0;
right: -3px;
width: 5px;
cursor: e-resize
}
.cropper-line.line-n {
top: -3px;
left: 0;
height: 5px;
cursor: n-resize
}
.cropper-line.line-w {
top: 0;
left: -3px;
width: 5px;
cursor: w-resize
}
.cropper-line.line-s {
bottom: -3px;
left: 0;
height: 5px;
cursor: s-resize
}
.cropper-point {
width: 5px;
height: 5px;
opacity: .75;
background-color: #39f
}
.cropper-point.point-e {
top: 50%;
right: -3px;
margin-top: -3px;
cursor: e-resize
}
.cropper-point.point-n {
top: -3px;
left: 50%;
margin-left: -3px;
cursor: n-resize
}
.cropper-point.point-w {
top: 50%;
left: -3px;
margin-top: -3px;
cursor: w-resize
}
.cropper-point.point-s {
bottom: -3px;
left: 50%;
margin-left: -3px;
cursor: s-resize
}
.cropper-point.point-ne {
top: -3px;
right: -3px;
cursor: ne-resize
}
.cropper-point.point-nw {
top: -3px;
left: -3px;
cursor: nw-resize
}
.cropper-point.point-sw {
bottom: -3px;
left: -3px;
cursor: sw-resize
}
.cropper-point.point-se {
right: -3px;
bottom: -3px;
width: 20px;
height: 20px;
cursor: se-resize;
opacity: 1
}
@media (min-width: 768px) {
.cropper-point.point-se {
width: 15px;
height: 15px
}
}
@media (min-width: 992px) {
.cropper-point.point-se {
width: 10px;
height: 10px
}
}
@media (min-width: 1200px) {
.cropper-point.point-se {
width: 5px;
height: 5px;
opacity: .75
}
}
.cropper-point.point-se:before {
position: absolute;
right: -50%;
bottom: -50%;
display: block;
width: 200%;
height: 200%;
content: ' ';
opacity: 0;
background-color: #39f
}
.cropper-invisible {
opacity: 0;
}
.cropper-bg {
background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0iAAAAA3NCSVQICAjb4U/gAAAABlBMVEXMzMz////TjRV2AAAACXBIWXMAAArrAAAK6wGCiw1aAAAAHHRFWHRTb2Z0d2FyZQBBZG9iZSBGaXJld29ya3MgQ1M26LyyjAAAABFJREFUCJlj+M/AgBVhF/0PAH6/D/HkDxOGAAAAAElFTkSuQmCC');
}
.cropper-hide {
position: absolute;
display: block;
width: 0;
height: 0;
}
.cropper-hidden {
display: none !important;
}
.cropper-move {
cursor: move;
}
.cropper-crop {
cursor: crosshair;
}
.cropper-disabled .cropper-drag-box,
.cropper-disabled .cropper-face,
.cropper-disabled .cropper-line,
.cropper-disabled .cropper-point {
cursor: not-allowed;
}
</style>
<!-- Add "scoped" attribute to limit CSS to this component only -->