將Drawable設置為imageView

Question

我目前正在嘗試檢索程序包的圖標，並使用此代碼將其設置為imageView。 ai是一個Drawable。

final PackageManager pm = getPackageManager();

try {
        ai = pm.getApplicationIcon(packageName);
    } catch (NameNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    Bitmap bitmap = ((BitmapDrawable)ai).getBitmap();

    Log.i("Icons Drawable", ai.toString());
    Log.i("Icons Bitmap", bitmap.toString());

imageView.setImageBitmap(bitmap);

Logcat輸出：

    11-06 11:10:22.785: I/Icons Drawable(20017): android.graphics.drawable.BitmapDrawable@416184f0
    11-06 11:10:22.785: I/Icons Bitmap(20017): android.graphics.Bitmap@41618488

11-06 11:10:22.790: E/AndroidRuntime(20017): FATAL EXCEPTION: main
11-06 11:10:22.790: E/AndroidRuntime(20017): java.lang.RuntimeException: Unable to start activity : java.lang.NullPointerException
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1973)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1999)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1159)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.os.Looper.loop(Looper.java:137)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.ActivityThread.main(ActivityThread.java:4513)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at java.lang.reflect.Method.invokeNative(Native Method)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at java.lang.reflect.Method.invoke(Method.java:511)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:974)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:741)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at dalvik.system.NativeStart.main(Native Method)
11-06 11:10:22.790: E/AndroidRuntime(20017): Caused by: java.lang.NullPointerException
11-06 11:10:22.790: E/AndroidRuntime(20017):    at com.analyze.project.MalwareAlertDialog.onCreate(MalwareAlertDialog.java:98)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.Activity.performCreate(Activity.java:4465)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
11-06 11:10:22.790: E/AndroidRuntime(20017):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1932)
11-06 11:10:22.790: E/AndroidRuntime(20017):    ... 11 more

即使我嘗試將Drawable直接設置為imageView也不起作用

imageView.setImageDrawable(ai);

Answer 1

嘗試這個

PackageManager pm = getPackageManager();
ApplicationInfo info=pm.getApplicationInfo(packageName,PackageManager.GET_META_DATA);
imageView.setImageDrawable(info.loadIcon(pm));

Answer 2

我建議您使用輸入流，這是一個示例

InputStream floorIs = context.getResources().openRawResource(R.drawable.floor_texture);

InputStream wallIs =context.getResources().openRawResource(R.drawable.wall_mayu_texture);

InputStream wallIs2 = context.getResources().openRawResource(R.drawable.wall_buzoo_texture);

InputStream wallIs3 = context.getResources().openRawResource(R.drawable.wall_niko_texture);

InputStream wallWindowIs =context.getResources().openRawResource(R.drawable.wall_window_texture);

InputStream ceilingIs = context.getResources().openRawResource(R.drawable.ceiling_texture);

Bitmap bitmaps[] = new Bitmap[6];
bitmaps[0] = null;
bitmaps[1] = null;
bitmaps[2] = null;
bitmaps[3] = null;
bitmaps[4] = null;
bitmaps[5] = null;
            try{
                bitmaps[0] = BitmapFactory.decodeStream(floorIs);
                bitmaps[1] = BitmapFactory.decodeStream(wallIs);
                bitmaps[2] = BitmapFactory.decodeStream(wallWindowIs);
                bitmaps[3] = BitmapFactory.decodeStream(ceilingIs);
                bitmaps[4] = BitmapFactory.decodeStream(wallIs2);
                bitmaps[5] = BitmapFactory.decodeStream(wallIs3);
            }
            finally{
                try{
                    floorIs.close();
                    floorIs = null;
                    wallIs.close();
                    wallIs = null;
                    wallIs2.close();
                    wallIs2 = null;
                    wallIs3.close();
                    wallIs3 = null;
                    wallWindowIs.close();
                    wallWindowIs = null;
                    ceilingIs.close();
                    ceilingIs = null;
                }
                catch(IOException e){}
            }

之后，嘗試將位圖加載到您在使用之前定義的imageview

imageView.setImageBitmap(bitmap[0]);

Answer 3

這可能是一個幼稚的問題，但是由於這是在您的onCreate（）回調中發生的，並且您為該ImageView獲取了空指針異常，您是否忘記了調用setContentView來膨脹您的布局？ 您的布局有可能從未創建過，這意味着您嘗試繪制的View也不存在。