OutOfMemoryError android 位图列表视图

Question

在我的应用程序中，我使用 SQLite 数据库来存储大量图像的数据。某些图像最大可达 600x600 像素。我使用自定义列表来创建位图。我知道有一个方法 bitmap.recycle();但我不确定如何将它与列表视图一起使用。

Answer 1

这里是在android中处理位图的解决方案

首先，你应该计算位图的sampleBitmapSize（加载相同位图的低版本）

    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;
    return BitmapFactory.decodeResource(res, resId, options);
}

下面是计算 InSampleSize（定义位图质量值（等级）的整数）的 util 函数。

    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) {

        final int halfHeight = height / 2;
        final int halfWidth = width / 2;

        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
        // height and width larger than the requested height and width.
        while ((halfHeight / inSampleSize) > reqHeight
                && (halfWidth / inSampleSize) > reqWidth) {
            inSampleSize *= 2;
        }
    }

    Log.i("ImageUtil", "InSampleSize: "+inSampleSize);
    return inSampleSize;
}