CursorAdapter如何在GridView中运行android

Question

我在gridview上使用游标适配器时遇到问题,我使用光标从媒体商店加载照片.我意识到我的newView和bindView被完全调用了.我的意思是假设我有500张照片,newView也会被调用相同的次数.

我做错了什么吗？我以为它只会在屏幕上看到细胞时调用..

    public int taskA = 0;

public GalleryCursorAdapter(Context context, Cursor c) {
    super(context, c);
    // TODO Auto-generated constructor stub
}

@Override
public void bindView(View view, Context context, Cursor cursor) {
    // TODO Auto-generated method stub
    int index = cursor.getColumnIndex(MediaStore.Images.Media._ID);
    long id = cursor.getLong(index);

    Bundle idBundle = new Bundle();
    idBundle.putLong("id", id);

    Message msg = new Message();
    msg.setData(idBundle);

    ImageHandler imgHandler = new ImageHandler(context, (ImageView) view);
    imgHandler.sendMessage(msg);

    view.setTag(imgHandler);
    Log.w("task s",  " count");
}

@SuppressLint({ "NewApi", "NewApi" })
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    // TODO Auto-generated method stub
    int index = cursor.getColumnIndex(MediaStore.Images.Media._ID);
    long id = cursor.getLong(index);

    ImageView iView = new ImageView(context);

    Bundle idBundle = new Bundle();
    idBundle.putLong("id", id);

    Message msg = new Message();
    msg.setData(idBundle);

    ImageHandler imgHandler = new ImageHandler(context, iView);
    imgHandler.sendMessage(msg);

    iView.setTag(imgHandler);
    taskA++;
    Log.w("task s", taskA+ " count");
    return iView;
}

static class ImageHandler extends Handler {

    private ImageView mView;
    private Context mContext;

    public ImageHandler(Context c, ImageView v) {
        mView = v;
        mContext = c;
    }

    @Override
    public void handleMessage(Message msg) {

        Bundle idBundle = msg.getData();

        Long id = idBundle.getLong("id");
        Bitmap image = MediaStore.Images.Thumbnails.getThumbnail(
                mContext.getContentResolver(), 
                id, 
                MediaStore.Images.Thumbnails.MICRO_KIND, 
                new Options());

        mView.setImageBitmap(image);
    }
}

Answer 1

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    ImageView iView = new ImageView(context);
    iView.setLayoutParams(new GridView.LayoutParams(200, 200));
    taskA++;
    Log.w("task s", taskA+ " count");
    return iView;
}

请注意,我删除了所有不应该在newView中的代码(它应该在bindView中)替换new GridView.LayoutParams(200, 200)为您需要的任何高度/宽度,不要使用换行内容,因为您的内容在开头是空的,导致0x0像素,因此光标中的所有ImageView都会立即进入GridView(因此每个视图都会调用newView和bindView)