Javascript 上载图像时未触发onprocess
我试图上传一个图像,并显示正在进行的加载百分比Javascript 上载图像时未触发onprocess,javascript,html,Javascript,Html,我试图上传一个图像,并显示正在进行的加载百分比 <!DOCTYPE html> <html> <head> <title></title> <script type="text/javascript"> function myFunction(){ console.dir(event.target.files[0].name); var read
<!DOCTYPE html>
<html>
<head>
<title></title>
<script type="text/javascript">
function myFunction(){
console.dir(event.target.files[0].name);
var reader = new FileReader();
reader.onprogress = function(progressEvent) {
if(progressEvent.lengthComputable) {
var percentLoaded = Math.round( (
progressEvent.loaded * 100) / progressEvent.total );
}
console.log("total: " + progressEvent.total + ", loaded: "
+ progressEvent.loaded + "(" + percentLoaded + "%)");
}
}
</script>
</head>
<body>
<input type="file" id="myFile" accept="image/*" onchange="myFunction()">
</body>
</html>
函数myFunction(){
console.dir(event.target.files[0].name);
var reader=new FileReader();
reader.onprogress=函数(progressEvent){
if(progressEvent.LengthComputeable){
var percentLoaded=数学四舍五入((
progressEvent.loaded*100)/progressEvent.total);
}
console.log(“总计:+progressEvent.total+”,已加载:
+progressEvent.loaded+”(“+percentLoaded+”)”;
}
}
当我上传图像时,会触发“onchange”。但是reader.onprogress不会被触发。如何触发onprocess事件?
事件
在函数中未定义。因此,在change函数中传递事件
,并通过readAsDataURL
将文件插入读卡器
函数
函数myFunction(e){
console.dir(e.target.files[0].name);
var reader=new FileReader();
reader.readAsDataURL(e.target.files[0])//将文件插入读取器
reader.onprogress=函数(progressEvent){
if(progressEvent.LengthComputeable){
var percentLoaded=Math.round((
progressEvent.loaded*100)/progressEvent.total);
}
console.log(“总计:+progressEvent.total+”,已加载:+
progressEvent.loaded+”(“+percentLoaded+”)”;
}
}