安卓：未能縮小位圖對象

-1

下面的代碼是從Android的開發人員採用，很少有變化：安卓：未能縮小位圖對象

private 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; 
     } 
    } 

    return inSampleSize; 
} 

public static Bitmap decodeSampledBitmap(Bitmap bitmap, int reqWidth, 
     int reqHeight) { 

    int size = bitmap.getRowBytes() * bitmap.getHeight(); 
    InputStream is = new ByteArrayInputStream(new byte[size]); 

    final BitmapFactory.Options options = new BitmapFactory.Options(); 
    options.inJustDecodeBounds = true; 
    BitmapFactory.decodeStream(is, null, options); 
      // I set these manually because decodeStream set them to -1 
    options.outHeight = bitmap.getHeight(); 
    options.outWidth = bitmap.getWidth(); 

    // Calculate inSampleSize 
    options.inSampleSize = calculateInSampleSize(options, reqWidth, 
      reqHeight); 

    // Decode bitmap with inSampleSize set 
    options.inJustDecodeBounds = false; 
    // can the number of rows be wrong now? 
    size = bitmap.getRowBytes() * options.outHeight; 
    is = new ByteArrayInputStream(new byte[size]); 
    return BitmapFactory.decodeStream(is, null, options); 
}

我有兩個問題：

當decodeStream讀取位圖界限，選項.outHeight和options.outWidth都設置爲-1，我不知道爲什麼
公共方法返回null時，從我的設備的攝像頭（因此從文件讀取）位圖，但工作正常時位圖取自圖像t帽子已經存在於我的手機上（從畫廊中選擇）。

問題可能出在哪裏？謝謝！

來源

2013-12-20 Yotam

是你的目錄包含圖像？ – QuokMoon

您如何期望BitmapFactory解碼'is'，因爲它裏面什麼都沒有？（'new byte [size]'很空...） – njzk2

使用http://developer.android.com/reference/android/graphics/Bitmap.html createScaledBitmap – njzk2

看起來像圖像被損壞或未正確保存。在位圖返回爲空的霧狀情況下，這是問題。

通過將捕獲的圖像複製到桌面，您可以在桌面上的圖像查看器中查看圖像。

來源

2013-12-20 16:37:25

安卓：未能縮小位圖對象

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