javascript_FileLoad

<html>
<head>
<meta charset="utf-8">
<title>FileLoad</title>
</head>
<body>


<form name="display">
<input type="file" id="selfile"><br>
<textarea name="txt" rows="45" cols="150" readonly></textarea>
</form>

<script>
let obj1 = document.getElementById("selfile");

obj1.addEventListener("change",function(evt){

let file=evt.target.files;

//FileReaderの作成
let reader=new FileReader();
reader.readAsText(file[0]);

reader.onload = function(ev){
document.display.txt.value = reader.result;
}
},false);
</script>


</body>
</html>