java - 使用 Fragment 强制关闭图库

Question

当我启动 Gallery Fragment 时，我遇到了强制关闭。这不是 Gallery 中的代码自 Ranghunandan向我展示了那里出了什么问题。我认为(但我不确定)它在 ImageAdapter 内。我还将发布 LogCat

这是 Java 代码

import java.lang.ref.WeakReference;
import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.support.v4.util.LruCache;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class ImageAdapter extends BaseAdapter {

  private static final String TAG = "ImageAdapter";

  private Context mContext;

  public static final Integer[] TATTOOS = {
        R.drawable.tattoo1, R.drawable.tattoo2,
        R.drawable.tattoo3, R.drawable.tattoo4,
        R.drawable.tattoo5, R.drawable.tattoo6,
        R.drawable.tattoo7, R.drawable.tattoo8,
        R.drawable.tattoo9, R.drawable.tattoo10,
       /* R.drawable.tattoo11, R.drawable.tattoo12,
        R.drawable.tattoo13, R.drawable.tattoo14,
        R.drawable.tattoo15, R.drawable.tattoo16,
        R.drawable.tattoo17, R.drawable.tattoo18,
        R.drawable.tattoo19, R.drawable.tattoo20,
        R.drawable.tattoo21, R.drawable.tattoo22,
        R.drawable.tattoo23, R.drawable.tattoo24,
        R.drawable.tattoo25, R.drawable.tattoo26,
        R.drawable.tattoo27, R.drawable.tattoo28,
        R.drawable.tattoo29, R.drawable.tattoo30,
        R.drawable.tattoo31, R.drawable.tattoo32,
        R.drawable.tattoo33, R.drawable.tattoo34,
        R.drawable.tattoo35, R.drawable.tattoo36,
        R.drawable.tattoo37, R.drawable.tattoo38,
        R.drawable.tattoo39, R.drawable.tattoo40,
        R.drawable.tattoo41, R.drawable.tattoo42,
        R.drawable.tattoo43, R.drawable.tattoo44,
        R.drawable.tattoo45, R.drawable.tattoo46,
        R.drawable.tattoo47, R.drawable.tattoo48,
        R.drawable.tattoo49, R.drawable.tattoo50,
        R.drawable.tattoo51, R.drawable.tattoo52,
        R.drawable.tattoo53, R.drawable.tattoo54,
        R.drawable.tattoo55, R.drawable.tattoo56,
        R.drawable.tattoo57, R.drawable.tattoo58,
        R.drawable.tattoo59, R.drawable.tattoo60,
        R.drawable.tattoo61, R.drawable.tattoo62,
        R.drawable.tattoo63, R.drawable.tattoo64,
        R.drawable.tattoo65, R.drawable.tattoo66,
        R.drawable.tattoo67, R.drawable.tattoo68,
        R.drawable.tattoo69, R.drawable.tattoo70,
        R.drawable.tattoo71, R.drawable.tattoo72,
        R.drawable.tattoo73, R.drawable.tattoo74,
        R.drawable.tattoo75, R.drawable.tattoo76,
        R.drawable.tattoo77, R.drawable.tattoo78,
        R.drawable.tattoo79, R.drawable.tattoo80,
        R.drawable.tattoo81, R.drawable.tattoo82*/
  };

  private Bitmap mHolder = null;
  private static final int CACHE_SIZE = 30 * 1024 * 1024; // 8 MiB cache
  /** Cache to store all decoded images */
  private LruCache<Integer, Bitmap> mBitmapsCache = new LruCache<Integer, Bitmap>(CACHE_SIZE) {

    @Override
    protected int sizeOf(final Integer key, final Bitmap value) {
        return value.getByteCount();
    }

    @Override
    protected void entryRemoved(final boolean evicted, final Integer key, final Bitmap oldValue, final Bitmap newValue) {
        if (!oldValue.equals(mHolder)) {
            oldValue.recycle();
        }
    }
  };

  // Constructor
  public ImageAdapter(Context c){
    mContext = c;
    mHolder = BitmapFactory.decodeResource(c.getResources(), R.drawable.ic_launcher, null);
  }

  @Override
  public int getCount() {
    return TATTOOS.length;
  }

  @Override
  public Object getItem(int position) {
    return TATTOOS[position];
  }

  @Override
  public long getItemId(int position) {
    return position;
  }

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    //This actually is a bad solution, because every time convertView is reused, you will still initialize new ImageView, which is wrong
    //ImageView imageView = new ImageView(this.mContext);
    //new BitmapWorkerTask(imageView).execute(Tattoos[position]);
    //return imageView;

    //Better solution
    ImageView imageView;

    if (convertView == null) {
        imageView = new ImageView(this.mContext);

        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setLayoutParams(new GridView.LayoutParams(280, 280));
    } else {
        imageView = (ImageView) convertView;
        //re-use ImageView that already exists in memory
    }

    final Bitmap itemBitmap = mBitmapsCache.get(TATTOOS[position]);

    if (itemBitmap == null || itemBitmap.isRecycled()) {
        Log.e(TAG, position + " is missed, launch decode for " + TATTOOS[position]);
        imageView.setImageBitmap(mHolder);
        mBitmapsCache.put(TATTOOS[position], mHolder);
        new BitmapWorkerTask(mBitmapsCache, mContext.getResources(), this).execute(TATTOOS[position]);
    } else {
        Log.e(TAG, position + " is here for " + TATTOOS[position]);
        imageView.setImageBitmap(itemBitmap);
    }

    return imageView;
  }

  /** AsyncTask for decoding images from resources */
  static class BitmapWorkerTask extends AsyncTask<Integer, Void, Bitmap> {
    private int data = 0;
    private final LruCache<Integer, Bitmap> mCache;
    private final Resources mRes;
    private final BaseAdapter mAdapter;

    public BitmapWorkerTask(LruCache<Integer, Bitmap> cache, Resources res, BaseAdapter adapter) {
        // nothing to do here
        mCache = cache;
        mRes = res;
        mAdapter = adapter;
    }

    // Decode image in background.
    @Override
    protected Bitmap doInBackground(Integer... params) {
        data = params[0];
        return decodeSampledBitmapFromResource(mRes, data, 300, 300);
    }

    // Once complete, see if ImageView is still around and set bitmap.
    @Override
    protected void onPostExecute(Bitmap bitmap) {
        mCache.put(data, bitmap);
        mAdapter.notifyDataSetChanged();
    }
  }

  public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
                                                     int reqWidth, int reqHeight) {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeResource(res, resId, options);

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    options.outHeight = 300;
    options.outWidth = 300;
    return BitmapFactory.decodeResource(res, resId, options);
  }

  public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        // Calculate ratios of height and width to requested height and width
        final int heightRatio = Math.round((float) height / (float) reqHeight);
        final int widthRatio = Math.round((float) width / (float) reqWidth);

        // Choose the smallest ratio as inSampleSize value, this will guarantee
        // a final image with both dimensions larger than or equal to the
        // requested height and width.
        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
    }

    return inSampleSize;
  }
}

这是 LogCat

12-25 13:55:13.722: D/AndroidRuntime(7065): Shutting down VM
12-25 13:55:13.722: W/dalvikvm(7065): threadid=1: thread exiting with uncaught exception     (group=0x419c5b90)
12-25 13:55:13.752: D/dalvikvm(7065): GC_FOR_ALLOC freed 179K, 3% free 9923K/10136K,     paused 20ms, total 20ms
12-25 13:55:13.752: E/AndroidRuntime(7065): FATAL EXCEPTION: main
12-25 13:55:13.752: E/AndroidRuntime(7065): Process: info.androidhive.slidingmenu, PID:     7065
12-25 13:55:13.752: E/AndroidRuntime(7065): android.util.SuperNotCalledException:     Fragment GalleryActivity{4238f5d8 #0 id=0x7f0a0008} did not call through to     super.onActivityCreated()
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.Fragment.performActivityCreated(Fragment.java:1710)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.FragmentManagerImpl.moveToState(FragmentManager.java:908)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.BackStackRecord.run(BackStackRecord.java:684)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1447)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.FragmentManagerImpl$1.run(FragmentManager.java:443)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at             android.os.Handler.handleCallback(Handler.java:733)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at         android.os.Handler.dispatchMessage(Handler.java:95)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at         android.os.Looper.loop(Looper.java:137)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     android.app.ActivityThread.main(ActivityThread.java:4998)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     java.lang.reflect.Method.invokeNative(Native Method)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     java.lang.reflect.Method.invoke(Method.java:515)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at     com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
12-25 13:55:13.752: E/AndroidRuntime(7065):     at         dalvik.system.NativeStart.main(Native Method)
12-25 14:00:13.902: I/Process(7065): Sending signal. PID: 7065 SIG: 9

Answer 1

logcat 告诉您，您没有调用 super onActivityCreated()； 错误不在您的适配器中。在堆栈跟踪中查看这一行:

android.util.SuperNotCalledException:Fragment GalleryActivity{4238f5d8 #0 id=0x7f0a0008} 未调用 super.onActivityCreated()

onActivityCreated 方法需要此调用，并且应如下所示:

@Override
onActivityCreated(Bundle savedInstanceState) {
  super.onActivityCreated(savedInstanceState);
  // do something here
}