Android动画Drawable Error with BitmapDrawable

Question

我现在正在编写一个程序，使用android应用程序中的AnimationDraawable来播放图像列表。图像列表从服务器下载。但是我在我的程序中遇到了错误，无法将该drawable添加到AnimationDrawable中。谁能帮我？

这里是我的logcat捕获：

04-26 00:45:07.260: E/AndroidRuntime(17422): FATAL EXCEPTION: AsyncTask #2 
04-26 00:45:07.260: E/AndroidRuntime(17422): java.lang.RuntimeException: An error occured while executing doInBackground() 
04-26 00:45:07.260: E/AndroidRuntime(17422): at android.os.AsyncTask$3.done(AsyncTask.java:299) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.FutureTask.setException(FutureTask.java:124) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.FutureTask.run(FutureTask.java:137) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.lang.Thread.run(Thread.java:856) 
04-26 00:45:07.260: E/AndroidRuntime(17422): Caused by: java.lang.ClassCastException: android.graphics.drawable.BitmapDrawable cannot be cast to android.graphics.drawable.AnimationDrawable 
04-26 00:45:07.260: E/AndroidRuntime(17422): at com.tlab.shopping.Itemview$itemanimation.doInBackground(Itemview.java:1036) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at com.tlab.shopping.Itemview$itemanimation.doInBackground(Itemview.java:1) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at android.os.AsyncTask$2.call(AsyncTask.java:287) 
04-26 00:45:07.260: E/AndroidRuntime(17422): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 
04-26 00:45:07.260: E/AndroidRuntime(17422): ... 5 more 

这里是我的一段代码：

public static class itemanimation extends AsyncTask<String, Void, AnimationDrawable>{ 
    public Itemview myActivity; 
    public itemanimation(Itemview a) 
    { 
     myActivity = a; 
    } 

protected void onPreExecute(){ 
//text.setText("load"); 
} 

protected AnimationDrawable doInBackground(String... x){ 
Bitmap bmImg = null; 
URL myFileUrl =null; 
String code = x[0]; 
String cur_url = null; 
ImageView im = (ImageView) myActivity.findViewById(R.id.imageView1); 

AnimationDrawable anim = null;   
Object ob = im.getBackground();   
anim = (AnimationDrawable) ob; 

for (int frameIndex = 0; frameIndex < 4; frameIndex++) { 

    cur_url = "http://137.189.97.18/image/" + code + frameIndex +".jpg"; 
    try { 
    myFileUrl= new URL(cur_url); 
    } catch (MalformedURLException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
    } 
    try { 
    HttpURLConnection conn= (HttpURLConnection)myFileUrl.openConnection(); 
    conn.setDoInput(true); 
    conn.connect(); 
    int length = conn.getContentLength(); 
    int[] bitmapData =new int[length]; 
    byte[] bitmapData2 =new byte[length]; 
    InputStream is = conn.getInputStream(); 

    bmImg = BitmapFactory.decodeStream(is); 
    Bitmap bmp = Bitmap.createScaledBitmap(bmImg, 150, 150,true); 

    Drawable bmpImgDrawable = Drawable.createFromStream(is, code + frameIndex + ".jpg"); 
    anim.addFrame(bmpImgDrawable, 250); 

    } catch (IOException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
    } 

} 
anim.setOneShot(false); 
return anim; 

} 

protected void onProgressUpdate(){ 

} 

protected void onPostExecute(AnimationDrawable z){ 
ImageView image = (ImageView) myActivity.findViewById(R.id.imageView1); 

image.setBackgroundColor(00000000); 
//image.setImageBitmap(bmp); 
image.setBackgroundDrawable(z); 
z.stop();   
z.start(); 
} 
} 

Answer 1

因为它不是一个AnimationDrawable。它只是一个图像，所以它是一个BitmapDrawable。