Question

在我的应用程序中，我对图像文件发出网络请求，然后尝试减少生成的位图大小。我正在构建this文档。我有一个文件流要读取并解码为位图，而不是静态资源。正如您在下面的代码中看到的那样，我使用的是BufferredInputStream，因此在第二次调用decodeStream之前，我可以重置流。但是我在该语句之后记录的消息没有被打印，也没有创建位图。它甚至没有任何错误。以下是我如何从URL中读取和解码图像 -

URL url = new URL(params[0]);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();

InputStream inp = connection.getInputStream();
BufferedInputStream bufferedinp = new BufferedInputStream(inp);

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
_BitMap = BitmapFactory.decodeStream(bufferedinp, null, options);

Log.d(TAG,"imageanalysis init width: " + Integer.toString(options.outWidth));
Log.d(TAG,"imageanalysis init height: " + Integer.toString(options.outHeight));

// get system height and width here --  fixed for now
int reqWidth = 250;
int reqHeight = 220;

options.inSampleSize = Common.getInSampleSize(options, reqWidth, reqHeight);

options.inJustDecodeBounds = false;

bufferedinp.reset(); // resetting the stream to read from start
_BitMap = BitmapFactory.decodeStream(bufferedinp, null, options);

Log.d(TAG,"imageanalysis fin width: " + Integer.toString(_BitMap.getWidth())); // doesn't get logged
Log.d(TAG,"imageanalysis fin height" + Integer.toString(_BitMap.getHeight())); // doesn't get logged

仅供参考，getInSampleSize在这里工作正常（在我的情况下返回2） -

public static int getInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
{
    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;

        Log.d("Common", "imageananalysis halfHeight: " + Integer.toString(halfHeight));
        Log.d("Common", "imageananalysis halfWidth: " + Integer.toString(halfWidth));

        while((halfHeight / inSampleSize) > reqHeight
                && (halfWidth / inSampleSize) > reqWidth)
        {
            Log.d("Common", "imageanalysis in loop samplesize: " + Integer.toString(inSampleSize));
            inSampleSize *= 2;
        }
    }

    Log.d("Common", "imageanalysis ret samplesize: " + Integer.toString(inSampleSize));

    return inSampleSize;
}

这里有什么问题？任何帮助将不胜感激。

无法使用BufferredInputStream第二次解码流

0 个答案: