[英]Get image dataUrl before file upload in Angularjs | ng-file-upload
我正在調整圖像的大小,然后使用HTML5 Canvas將其上傳到服務器。
我也使用Angular的模塊ng-file-upload 。
堆棧上獲取調整大小后的圖像的dataUrl。 控制台返回data:,
這可能是什么問題?
的HTML
<input type="file" ngf-select ng-model="files">
<img ngf-src="files[0]">
JS
$scope.upload = function (files) {
if (files && files.length==1) {
var file = files[0];
var img = document.createElement("img");
var canvas = document.createElement("canvas");
var reader = new FileReader();
reader.onload = function(e) {img.src = e.target.result};
reader.readAsDataURL(file);
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
var MAX_WIDTH = 200;
var MAX_HEIGHT = 150;
var width = img.width;
var height = img.height;
if (width > height) {
if (width > MAX_WIDTH) {
height *= MAX_WIDTH / width;
width = MAX_WIDTH;
}
} else {
if (height > MAX_HEIGHT) {
width *= MAX_HEIGHT / height;
height = MAX_HEIGHT;
}
}
canvas.width = width;
canvas.height = height;
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0, width, height);
var dataurl = canvas.toDataURL("image/png");
console.log( dataurl );
...
他有同樣的問題,並通過以下方法解決:
$scope.upload = function (files) { if (files && files.length==1) { var file = files[0]; var URL = window.URL || window.webkitURL; var srcTmp = URL.createObjectURL(file); var img = new Image(); img.onload = function() { alert(this.width + 'x' + this.height); } img.src = srcTmp;
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