Chrome FileReader [英] Chrome FileReader
本文介绍了Chrome FileReader的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
它似乎正在返回 undefined
<!doctype html>
< html>
< script>
函数handle_files(files){
console.log(files)
reader = new FileReader()
ret = []
for(i = 0; i< ; files.length; i ++){
file = files [i]
console.log(file)
text = reader.readAsText(file)// readAsdataURL
console.log (text)// undefined
ret.push(text)
}
console.log(ret)// [undefined]
}
< ; /脚本>
< body>
FileReader Test
< input type =fileonchange =handle_files(this.files)>
< / body>
< / html>
解决方案
我的问题是我认为FileReader是同步的。
这是正确的做法。
如果您使用的是chrome,则此代码必须在服务器上运行(本地主机或站点上)。它不会与本地文件一起工作。
<!doctype html>
< html>
< script>
函数handle_files(files){
for(i = 0; i< files.length; i ++){
file = files [i]
console.log(file)
var reader = new FileReader()
ret = []
reader.onload = function(e){
console.log(e.target.result)
}
reader.onerror = function(stuff){
console.log(error,stuff)
console.log(stuff.getMessage())
}
reader.readAsText(file)// readAsdataURL
}
}
< / script>
< body>
FileReader可以工作!
< input type =filemultiple onchange =handle_files(this.files)>
< / body>
< / html>
Can someone give me an example of using the FileReader API go get contents of a file in chrome?
It seems to be returning undefined
for me.
<!doctype html>
<html>
<script>
function handle_files(files) {
console.log(files)
reader = new FileReader()
ret = []
for (i = 0; i < files.length; i++) {
file = files[i]
console.log(file)
text = reader.readAsText(file) //readAsdataURL
console.log(text) //undefined
ret.push(text)
}
console.log(ret) // [undefined]
}
</script>
<body>
FileReader Test
<input type="file" onchange="handle_files(this.files)">
</body>
</html>
解决方案
My problem was that I assumed FileReader was sychronous. Here is the right way to do it. If you are on chrome, this code has to be running on a server (localhost or on a site). It won't work with a local file.
<!doctype html>
<html>
<script>
function handle_files(files) {
for (i = 0; i < files.length; i++) {
file = files[i]
console.log(file)
var reader = new FileReader()
ret = []
reader.onload = function(e) {
console.log(e.target.result)
}
reader.onerror = function(stuff) {
console.log("error", stuff)
console.log (stuff.getMessage())
}
reader.readAsText(file) //readAsdataURL
}
}
</script>
<body>
FileReader that works!
<input type="file" multiple onchange="handle_files(this.files)">
</body>
</html>
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