<template>
<div>
<div class="user-header">
<div class="blur" :style="'backgroundImage:url('+service+img_src+')'"></div>
<div class="info-wrap">
<div class="show-img">
<div class="picture-wrap" :style="'backgroundImage:url('+service+img_src+')'"></div>
<input type="file" id="upload-btn" ref="img_file" accept="image/*" @change="upload">
</div>
</div>
</div>
</div>
</template>
解決OIS 拍照旋轉(zhuǎn)等問題肋杖，結(jié)合H5 formData的方式上傳圖片溉仑，通過axios上傳到后臺
這里解決旋轉(zhuǎn)問題需要借助一個(gè)第三方哭 exif-js
庫已經(jīng)封裝到git
順手star 一下，多謝
https://github.com/CommanderXL/imgResize
重要的部分
image.png
<script>
import Exif from 'exif-js'
export default {
data () {
return {
headerImage:'',
picValue:'',
img_src:'/Uploads/2018-01-19/5a6197e1268c4.jpg'
}
},
mounted () {
},
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;
//去獲取拍照時(shí)的信息状植，解決拍出來的照片旋轉(zhuǎn)問題
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)) {
// 創(chuàng)建一個(gè)reader
let reader = new FileReader();
// 將圖片2將轉(zhuǎn)成 base64 格式
reader.readAsDataURL(file);
// 讀取成功后的回調(diào)
reader.onloadend = function () {
let result = this.result;
let img = new Image();
img.src = result;
//判斷圖片是否大于100K,是就直接上傳浊竟，反之壓縮圖片
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;
self.postImg();
}
}
}
}
},
postImg () {
//這里寫接口
let _this=this;
let uploadFile=new FormData();
let imgData=this.$refs['img_file'].files[0];
uploadFile.append('file',imgData);
this.$axios.post('api/test',
uploadFile
).then(function (response) {
console.log(_this.img_src)
console.log(response)
console.log(response.data.data.original);
_this.img_src=response.data.data.original;
console.log(_this.img_src)
})
.catch(function (error) {
console.log(error);
console.log('0')
});
},
rotateImg (img, direction,canvas) {
//最小與最大旋轉(zhuǎn)方向，圖片旋轉(zhuǎn)4次后回到原方向
const min_step = 0;
const max_step = 3;
if (img == null)return;
//img的高度和寬度不能在img元素隱藏后獲取津畸，否則會(huì)出錯(cuò)
let height = img.height;
let width = img.width;
let step = 2;
if (step == null) {
step = min_step;
}
if (direction == 'right') {
step++;
//旋轉(zhuǎn)到原位置振定，即超過最大值
step > max_step && (step = min_step);
} else {
step--;
step < min_step && (step = max_step);
}
//旋轉(zhuǎn)角度以弧度值為參數(shù)
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;
//如果圖片大于四百萬像素，計(jì)算壓縮比并將大小壓至400萬以下
let ratio;
if ((ratio = width * height / 4000000) > 1) {
console.log("大于400萬像素");
ratio = Math.sqrt(ratio);
width /= ratio;
height /= ratio;
} else {
ratio = 1;
}
canvas.width = width;
canvas.height = height;
// 鋪底色
ctx.fillStyle = "#fff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
//如果圖片像素大于100萬則使用瓦片繪制
let count;
if ((count = width * height / 1000000) > 1) {
console.log("超過100W像素");
count = ~~(Math.sqrt(count) + 1); //計(jì)算要分成多少塊瓦片
// 計(jì)算每塊瓦片的寬和高
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);
}
//修復(fù)ios上傳圖片的時(shí)候 被旋轉(zhuǎn)的問題
if(Orientation != "" && Orientation != 1){
switch(Orientation){
case 6://需要順時(shí)針（向左）90度旋轉(zhuǎn)
this.rotateImg(img,'left',canvas);
break;
case 8://需要逆時(shí)針（向右）90度旋轉(zhuǎn)
this.rotateImg(img,'right',canvas);
break;
case 3://需要180度旋轉(zhuǎn)
this.rotateImg(img,'right',canvas);//轉(zhuǎn)兩次
this.rotateImg(img,'right',canvas);
break;
}
}
//進(jìn)行最小壓縮
let ndata = canvas.toDataURL('image/jpeg/gif', 0.5);
console.log('壓縮前：' + initSize);
console.log('壓縮后：' + ndata.length);
console.log('壓縮率：' + ~~(100 * (initSize - ndata.length) / initSize) + "%");
tCanvas.width = tCanvas.height = canvas.width = canvas.height = 0;
return ndata;
},
}
}
</script>
