將圖象到listarray從資產文件夾

Question

我希望把位圖圖像的ListView，

我用這個方法：

public Drawable getAssetImage(Context context, String filename) throws IOException { 
    AssetManager assets = getAssets(); 
    InputStream buffer = new BufferedInputStream((assets.open("flags/" + filename + ".png"))); 
    Bitmap bitmap = BitmapFactory.decodeStream(buffer); 
    return new BitmapDrawable(bitmap); 
} 

，然後，我投入的HashMap：

temp.put("Icon", getAssetImage(this, "Cyprus")); 

我有我的資產/標誌圖標

這裏我們有錯誤日誌：

06-13 12:39:12.236: ERROR/AndroidRuntime(10934): FATAL EXCEPTION: main 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934): java.lang.NullPointerException 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.content.ContextWrapper.getResources(ContextWrapper.java:80) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at com.project.castroll.DataBaseHelper.getAssetImage(DataBaseHelper.java:111) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at com.project.castroll.DataBaseHelper.selectAll(DataBaseHelper.java:96) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at com.project.castroll.CastrollApp.showKwalifikacja(CastrollApp.java:282) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at com.project.castroll.CastrollApp$2.onClick(CastrollApp.java:255) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.view.View.performClick(View.java:2485) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.view.View$PerformClick.run(View.java:9080) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.os.Handler.handleCallback(Handler.java:587) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.os.Handler.dispatchMessage(Handler.java:92) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.os.Looper.loop(Looper.java:123) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at android.app.ActivityThread.main(ActivityThread.java:3683) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at java.lang.reflect.Method.invoke(Method.java:507) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
06-13 12:39:12.236: ERROR/AndroidRuntime(10934):  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

不存儲可繪製在HashMap中使用你自己的實現SimpleAdapter像這樣 （如 「圖標」，在HashMap中只放文件名）

public class MySimpleAdapter extends SimpleAdapter{ 

     Context localcontext = null; 

     public MySimpleAdapter(Context context, 
       List<? extends Map<String, ?>> data, int resource, 
       String[] from, int[] to) { 
      super(context, data, resource, from, to); 
      localcontext = context; 
     } 

     @Override 
     public void setViewImage(ImageView v, String value){ 
      try { 
       v.setImageDrawable(Drawable.createFromStream(localcontext.getAssets().open("flags/" + value + ".png"), null)); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
     } 

//EDIT ... he ask how to add odd/even row with diff colours 

     private int[] colors = new int[] { 0xe0e0e0ff, 0x404040ff }; 

     @Override 
     public View getView(int position, View convertView, ViewGroup parent) { 
      View view = super.getView(position, convertView, parent); 
      int colorPos = position % colors.length; 
      view.setBackgroundColor(colors[colorPos]); 
      return view; 
     } 
    } 

和使用，而不是SimpleAdapter