js獲取上傳圖片寬高
阿新 • • 發佈:2019-01-31
直接程式碼
<!DOCTYPE html>
<html>
<head>
<title>獲取上傳圖片的寬高</title>
</head>
<body>
<form>
<input type="file" name="img_upload" id="img_upload" onchange="imgUpload();" />
</form>
</body>
<script type="text/javascript">
function imgUpload() {
var file = document.getElementById('img_upload');
createReader(file.files[0], function (w, h) { alert(w + ' '+ h)});
}
createReader = function(file, whenReady) {
var reader = new FileReader;
reader.onload = function (evt) {
var image = new Image();
image.onload = function () {
var width = this.width;
var height = this.height;
if (whenReady) whenReady(width, height);
};
image.src = evt.target.result;
};
reader.readAsDataURL(file);
}
</script>
</html>
執行結果: