BitmapFactory返回空Android

Question

好的，所以我下载了一张图片，并将输入流发送到这个方法，它必须解码一次以找到图像大小，然后计算比例值，然后根据流创建一个迷你版本的位图……但是我在logcat中得到了错误，bitmapFactory返回null，有人知道会出什么问题吗？

public static Bitmap getSampleBitmapFromStream(InputStream is,
        int reqWidth, int reqHeight) {

    BitmapFactory.Options options = new BitmapFactory.Options();

    options.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(new FlushedInputStream(is), null, options);


    // Find the correct scale value. It should be the power of 2.
    int width_tmp = options.outWidth, height_tmp = options.outHeight;
    int scale = 1;
    while (true) {
        if (width_tmp / 2 < reqWidth || height_tmp / 2 < reqHeight)
            break;
        width_tmp /= 2;
        height_tmp /= 2;
        scale *= 2;
    }

    // decode with inSampleSize
    options.inJustDecodeBounds = false;
            options.inSampleSize = scale;
    return BitmapFactory.decodeStream(new FlushedInputStream(is), null, options);

}

Answer 1

原因是:您使用了两次的流

options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FlushedInputStream(is), null, options);

再说一遍：

 options.inJustDecodeBounds = false;
        options.inSampleSize = scale;
return BitmapFactory.decodeStream(new FlushedInputStream(is), null, options);

因此，如果您想避免这种情况，您需要关闭流，然后重新打开流。

Answer 2

直接提供InputStream怎么样？

return BitmapFactory.decodeStream(is, null, options);