layui的upload上传前压缩一下图片
编辑时间：2019-06-02
作者：金满斗
浏览量：3753
来源：原创
别人的，我转载的，废话不说，直接上代码。
html
<div>
<button type="button" class="layui-btn" id="up_pic_btn">上传图片</button>
<input type="button" id = "btnHide" class="none"> <!-- 用于模拟自动上传-->
</div>
layui.config({
version: "{:ver()}",
base: '/Public/layui/src/lay/'
}).extend({
photoZip: 'plug/photoZip',
}).use(['upload', 'photoZip'], function () {
var upload = layui.upload;
var photoZip = layui.photoZip;
var uploadInst = upload.render({
elem: '#up_pic_btn',
accept: 'file',
exts: 'jpg|jpge|gif|png',
size: 1024 * 10,
url: '//upload-z2.qiniup.com/',
uptoken_url: layfun.config.hostService + 'service/uptoken.html',
auto: false,
bindAction: "#btnHide",
multiple: true,
choose: function (obj) {
var files = this.files = obj.pushFile();
var oindex,
indexArr = [];
for (oindex in files) {
indexArr.push(oindex);
};
eindex = 0;
star = 0;
var len = indexArr.length;
obj.preview(function (index, file, result) {
try {
if (file.size > 800 * 1024) {
(star == 0) && layer.msg("照片压缩中...", {
time: false
}, star = 1);
photoZip.photoCompress(file, {
quality: 0.9,
width: 1200
}, function (base64Codes) {
delete files[index];
obj.resetFile(index, photoZip.convertBase64UrlToBlob(base64Codes), file.name);
eindex++;
console.log(eindex);
console.log(len);
if (eindex == len) {
layer.msg("全部照片已经压缩成功", function () {
layer.msg("开始上传...", {
time: false
});
$("#btnHide").trigger("click");
});
}
});
}
} catch (e) {
layer.msg("全部照片已经压缩成功", function () {
layer.msg("开始上传...", {
time: false
});
$("#btnHide").trigger("click");
});
}
})
},
before: function (obj) {
!filelist.list && (filelist.list = []);
},
allDone: function (obj) {
layfun.plupostdatatoqiniu(JSON.stringify(filelist), filekey, layfun.config.backname).then(function (res) {
pagelist.setdrarp();
layer.msg("上传成功...", {
time: 500
})
})
},
done: function (res, index, upload) {
delete this.files[index];
filelist.list.push({
id: (new Date()).getTime(),
tmbPath: layfun.config.fileHost + res.key,
key: res.key,
usetime: 0
})
}
});
});
layui.define(function (exports) {
var photoZip = {
photoCompress: function (file, w, objDiv) {
var ready = new FileReader();
/*开始读取指定的Blob对象或File对象中的内容. 当读取操作完成时,readyState属性的值会成为DONE,如果设置了onloadend事件处理程序,则调用之.同时,result属性中将包含一个data: URL格式的字符串以表示所读取文件的内容.*/
ready.readAsDataURL(file);
ready.onload = function () {
var re = this.result;
photoZip.canvasDataURL(re, w, objDiv);
}
},
canvasDataURL: function (path, obj, callback) {
var img = new Image();
img.src = path;
img.onload = function () {
var that = this;
// 默认按比例压缩
var w = that.width,
h = that.height,
scale = w / h;
w = obj.width || w;
h = obj.height || (w / scale);
var quality = 0.5; // 默认图片质量为0.7
//生成canvas
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
// 创建属性节点
var anw = document.createAttribute("width");
anw.nodeValue = w;
var anh = document.createAttribute("height");
anh.nodeValue = h;
canvas.setAttributeNode(anw);
canvas.setAttributeNode(anh);
ctx.drawImage(that, 0, 0, w, h);
// 图像质量
if (obj.quality && obj.quality <= 1 && obj.quality > 0) {
quality = obj.quality;
}
// quality值越小，所绘制出的图像越模糊
var base64 = canvas.toDataURL('image/jpeg', quality);
// 回调函数返回base64的值
callback(base64);
}
},
convertBase64UrlToBlob: function (urlData) {
var arr = urlData.split(','),
mime = arr[0].match(/:(.*?);/)[1],
bstr = atob(arr[1]),
n = bstr.length,
u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
return new Blob([u8arr], {
type: mime
});
}
};
exports('photoZip', photoZip)
})
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