最佳答案
Adobe AIR对canvas API中使用的图像强制执行相同的原点.一旦您在画布中使用了来自其他域的内容,就无法从中获取像素数据.但是,您可以使用Loader类来获取像素数据,并将其转换为画布ImageData.
例如：
function getDataURL(url,callback) {var loader = new air.Loader();loader.contentLoaderInfo.addEventListener(air.Event.COMPLETE,function(event) {var bitmapData = loader.content.bitmapData;var canvas = document.createElement('canvas');canvas.width = bitmapData.width;canvas.height = bitmapData.height;var context = canvas.getContext('2d');var imageData = context.createImageData(canvas.width,canvas.height);var dst = imageData.data;var src = bitmapData.getPixels(bitmapData.rect);src.position = 0;var i = 0;while (i < dst.length) {var alpha = src.readUnsignedByte();dst[i++] = src.readUnsignedByte();dst[i++] = src.readUnsignedByte();dst[i++] = src.readUnsignedByte();dst[i++] = alpha;}context.putImageData(imageData,0);callback(canvas.toDataURL());});loader.load(new air.URLRequest(url));}window.addEventListener('load',function() {getDataURL('http://www.google.com/images/logo.gif',function(dataURL) {air.trace(dataURL);});},false);
