Windows Phone 7学习笔记（一）--BitmapImage转化为WriteableBitmap

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南倭瓜 2014-04-15 16:49:21 博主文章分类：Winphone

　今天写代码的时候，遇到需要将BitmapImage转化为WriteableBitmap,自己果断写下如下代码。结果调试的时候每次都报错。

BitmapImage bitmapImage = new BitmapImage(new Uri("/p_w_picpaths/test.png",UriKind.Relative));WriteableBitmap writeableBitmap = new WriteableBitmap(bitmapImage);

　　自己尝试设置图片的属性，无论是resource还是content也都不行，地址也是绝对相对都换过，还是不行。

　　最后google到发现bitmapImage原来是异步加载图片，也就说我创建writeablebitmap的时候bitmapp_w_picpath还没有加载完成，所以报错。

　　于是就有了

///do something...
            Uri url = new Uri("/Img/1.png", UriKind.Relative);            BitmapImage bitmapImage = new BitmapImage();            bitmapImage.CreateOptions = BitmapCreateOptions.None;            bitmapImage.ImageOpened += bitmapImage_ImageOpened;            bitmapImage.UriSource = url;            bitmapImage.ImageFailed += bitmapImage_ImageFailed;} void bitmapImage_ImageOpened(object sender, RoutedEventArgs e)        {            WriteableBitmap wb = new WriteableBitmap(sender as BitmapImage);            ///do something...
        }

　　当然也可以这么写：

Uri url = new Uri("/Img/1.png", UriKind.Relative);BitmapImage bitmapImage = new BitmapImage();bitmapImage.CreateOptions = BitmapCreateOptions.None;bitmapImage.ImageOpened +=(o,args)=>
    {
        WriteableBitmap wb = new WriteableBitmap(o as BitmapImage);
///do something ...
    }; 
bitmapImage.UriSource = url;