1.这种压缩方法是获取到图片,然后截取之后进行压缩的
`
<template>
<div class="cropper-page">
<slot>
<button @click="upload">上传图片</button>
</slot>
<div id="demo">
<!-- 遮罩层 -->
<div class="container" v-show="panel">
<div class="cropper-box">
<img id="image" :src="url" alt="Picture">
</div>
<div class="bottom-btn-box">
<button type="button" class="del-btn" @click="stopCrop">取消</button>
<button type="button" class="sure-btn" @click="crop">确定</button>
</div>
</div>
<div class="cropper-warpper">
<input type="file" id="change" ref="file" :value="filevalue" class="cropper-hidden" accept="image" @change="change">
<label class="cropper-label" for="change">
<slot></slot>
</label>
</div>
</div>
</div>
</template>
<script>
import Cropper from "cropperjs";
export default {
props: {
quality: Number,
default: 1
},
components: {},
data () {
return {
headerImage: "",
picValue: "",
cropper: "",
croppable: false,
panel: false,
url: "",
filevalue: ""
};
},
mounted () {
//初始化这个裁剪框
var self = this;
var image = document.getElementById("image");
this.cropper = new Cropper(image, {
aspectRatio: 1,
viewMode: 1,
background: false,
zoomable: false,
ready: function () {
self.croppable = true;
}
});
},
methods: {
// 点击上传按钮
upload () {
// this.$refs['file'].change()
this.$refs['file'].dispatchEvent(new MouseEvent('click'))
},
getObjectURL (file) {
var 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;
},
change (e) {
console.log(e);
let files = e.target.files || e.dataTransfer.files;
if (!files.length) return;
this.panel = true;
this.picValue = files[0];
this.url = 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.url);
// }
// this.panel = true;
//对图片压缩处理
let img_size = this.picValue.size;
this.filename = this.picValue.name;
let render = new FileReader();
render.readAsDataURL(this.picValue);
render.onload = e => {
if (img_size >= 1024 * 1024 * 0.2) {
console.log("图片过大");
//调用自定义方法来处理图片
this.compressImage(e.target.result);
} else {
this.url = 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.url);
}
this.panel = true;
}
};
// this.$vux.loading.show();
},
compressImage: function (bdata) {
//压缩图片
var _this = this;
var quality = 0.3; //压缩图片的质量
var oldimglength = bdata.length; //压缩前的大小
var compresRadio = 0; // 压缩率
var canvas = document.createElement("canvas"); //创建画布
var ctx = canvas.getContext("2d");
var img = new Image();
img.src = bdata;
img.onload = function () {
var width = img.width;
var height = img.height;
canvas.width = 100; //这里可以自定义你的图片大小
canvas.height = 100 * (img.height / img.width);
ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
var cdata = canvas.toDataURL("image/jpeg", quality); //将图片转为Base64 之后预览要用
// _this.HeadUrl = cdata; //预览你压缩后的图片
var newimglength = cdata.length;
console.log(newimglength);
console.log("img-blob:" + oldimglength); //压缩前大小
console.log("ctx-blob:" + newimglength); //压缩后大小
compresRadio =
(((oldimglength - newimglength) / oldimglength) * 100).toFixed(2) +
"%";
console.log("压缩率:" + compresRadio);
//base64转成file
let arr = cdata.split(",");
let mime = arr[0].match(/:(.*?);/)[1];
let bstr = atob(arr[1]);
let n = bstr.length;
let u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
let newFile = new File([u8arr], _this.filename, { type: mime });
// console.log(this.picValue)
_this.url = _this.getObjectURL(newFile);
//每次替换图片要重新得到新的url
if (_this.cropper) {
_this.cropper.replace(this.url);
}
_this.panel = true;
};
},
stopCrop () {
this.panel = false;
},
crop () {
console.log(this.quality);
// let quality = 0.3
// this.$vux.loading.show();
var croppedCanvas;
var roundedCanvas;
if (!this.croppable) {
return;
}
// Crop
croppedCanvas = this.cropper.getCroppedCanvas();
console.log(this.cropper);
// Round
roundedCanvas = this.getRoundedCanvas(croppedCanvas);
this.headerImage = roundedCanvas.toDataURL("image/jpeg", this.quality);
this.$emit("getUrlBase64", this.headerImage);
console.log(this.headerImage);
// this.$vux.loading.hide();
this.panel = false;
},
getRoundedCanvas (sourceCanvas) {
var canvas = document.createElement("canvas");
var context = canvas.getContext("2d");
var width = sourceCanvas.width;
var 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();
//圆形
// context.arc(
// width / 2,
// height / 2,
// Math.min(width, height) / 2,
// 0,
// 2 * Math.PI,
// true
// );
//矩形
context.rect(0, 0, width, height);
context.fill();
return canvas;
}
}
};
</script>
<style lang="scss">
.cropper-page {
* {
margin: 0;
padding: 0;
}
.cropper-warpper {
display: flex;
align-items: center;
}
.cropper-box {
width: 100%;
height: 80%;
position: absolute;
top: 50%;
transform: translateY(-50%);
}
#demo #button {
position: absolute;
right: 10px;
top: 10px;
width: 80px;
height: 40px;
border: none;
border-radius: 5px;
background: white;
}
.bottom-btn-box {
display: flex;
justify-content: space-between;
position: absolute;
width: 100%;
left: 0;
bottom: 0;
button {
outline: none;
border: none;
padding: 5px 20px;
border-radius: 2px;
font-size: 16px;
color: #fff;
background: #f05b47;
margin: 15px;
&.del-btn {
background: #aaa;
}
}
}
#demo .show {
width: 100px;
height: 100px;
overflow: hidden;
position: relative;
border-radius: 50%;
border: 1px solid #d5d5d5;
}
#demo .picture {
width: 100%;
height: 100%;
overflow: hidden;
background-position: center center;
background-repeat: no-repeat;
background-size: cover;
}
#demo .container {
z-index: 99;
position: fixed;
// padding-top: 60px;
left: 0;
top: 0;
right: 0;
bottom: 0;
background: rgba(0, 0, 0, 1);
}
#demo #image {
max-width: 100%;
}
.cropper-view-box,
.cropper-face {
// border-radius: 50%;
}
/*!
* Cropper.js v1.0.0-rc
* https://github.com/fengyuanchen/cropperjs
*
* Copyright (c) 2017 Fengyuan Chen
* Released under the MIT license
*
* Date: 2017-03-25T12:02:21.062Z
*/
.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;
}
.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: 0.5;
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: 0.5;
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: 0.75;
}
.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: 0.1;
}
.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: 0.75;
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: 0.75;
}
}
.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;
}
.camera {
width: 30px;
height: 26px;
display: block;
margin-left: 30px;
img {
width: 100%;
height: 100%;
}
}
.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>
`
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