4

我在OutOfMemoryError向gridview添加可变背景时得到...

final Bitmap shelfBackground = BitmapFactory.decodeResource(resources, background);

这是我的代码。

public class ShelvesView extends GridView {
    private Bitmap mShelfBackground;
    private int mShelfWidth;
    private int mShelfHeight;
    public ShelvesView(Context context) {
        super(context);
    }
    public ShelvesView(Context context, AttributeSet attrs) {
        super(context, attrs);
        load(context, attrs, 0);
    }
    public ShelvesView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        load(context, attrs, defStyle);
    }

    private void load(Context context, AttributeSet attrs, int defStyle) {
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ShelvesView,   defStyle, 0);
        int imageWidth = options.outWidth;
        final Resources resources = getResources();
        final int background = a.getResourceId(R.styleable.ShelvesView_shelfBackground, 0);
        final Bitmap shelfBackground = BitmapFactory.decodeResource(resources, background);
        if (shelfBackground != null) {
            mShelfWidth = shelfBackground.getWidth();
            mShelfHeight = shelfBackground.getHeight();
            mShelfBackground = shelfBackground;
        }

        a.recycle();
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        final int count = getChildCount();
        final int top = count > 0 ? getChildAt(0).getTop() : 0;
        final int shelfWidth = mShelfWidth;
        final int shelfHeight = mShelfHeight;
        final int width = getWidth();
        final int height = getHeight();
        int bottom = (count > 0) ? getChildAt(count - 5).getBottom() + shelfHeight : 0;
        final Bitmap background = mShelfBackground;
        for (int x = 0; x < width; x += shelfWidth) {
            for (int y = top; y < height; y += shelfHeight) {
                canvas.drawBitmap(background, x, y, null);
            }
        }

        //drawDecorations(canvas, top, shelfHeight, width);

        // canvas.drawBitmap(mShelfLeftLayer,0,bottom, null);

        super.dispatchDraw(canvas);
    }

}
4

3 回答 3

4

向其添加位图选项 -

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
shelfBackground = BitmapFactory.decodeResource(resources, background, options);
于 2012-09-26T07:35:17.820 回答
2

使用 Android SDK 中的示例从 UI 线程处理图像：

class BitmapWorkerTask extends AsyncTask<Integer, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
private int data = 0;

public BitmapWorkerTask(ImageView imageView) {
    // Use a WeakReference to ensure the ImageView can be garbage collected
    imageViewReference = new WeakReference<ImageView>(imageView);
}

// Decode image in background.
@Override
protected Bitmap doInBackground(Integer... params) {
    data = params[0];
    return decodeSampledBitmapFromResource(getResources(), data, 100, 100));
}

// Once complete, see if ImageView is still around and set bitmap.
@Override
protected void onPostExecute(Bitmap bitmap) {
    if (imageViewReference != null && bitmap != null) {
        final ImageView imageView = imageViewReference.get();
        if (imageView != null) {
            imageView.setImageBitmap(bitmap);
        }
    }
}

}

在这里您可以找到更多使用sampleSize decodeResource进行解码的示例。

于 2012-09-26T07:38:11.867 回答
1

您可以使用 BitmapFactory.Options 类将图像裁剪为任意大小。

您可以使用以下内容：

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
options.inSampleSize = 8; // 1/8th of actual image.
BitmapFactory.decodeResource(getResources(), R.id.myimage, options);
int imageHeight = options.outHeight;
int imageWidth = options.outWidth;
String imageType = options.outMimeType;

有关更多信息，请参阅此。

在这里，当您使用 a 时Bitmap，请始终调用其bmp.recycle()方法，因为GC无法清除 持有的内存Bitmap，如果您的位图没有被垃圾收集，那么您也会得到OME.

我也给出了通用的解决方案，请看这个。

于 2012-09-26T07:46:36.110 回答