如何调整我从 android 的画廊中挑选的图像的大小？答案

【问题标题】：How to resize an image i picked from the gallery in android?如何调整我从 android 的画廊中挑选的图像的大小？
【发布时间】：2012-06-02 03:55:14
【问题描述】：

我正在哪里构建一个 android。在一项活动中，我有一个图像按钮。当我点击它时，画廊会打开，我可以选择一张图片。然后我将该图像设置为图像按钮的新图像。问题是图像在我的活动中显得太大了。如何使它适合我的图像按钮？

protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) { 
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent); 

    switch(requestCode) { 
    case SELECT_PHOTO:
        if(resultCode == RESULT_OK){  
            Uri selectedImage = imageReturnedIntent.getData();
            String[] filePathColumn = {MediaStore.Images.Media.DATA};

            Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String filePath = cursor.getString(columnIndex);
            cursor.close();


            Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);

            mImageButton.setImageBitmap(yourSelectedImage);
        }
    }
}

【问题讨论】：

标签： android image resize gallery

【解决方案1】：

您可以使用此方法获取调整大小的图像。这样可以避免 OutOfMemoryError

public static Bitmap decodeUri(Context c, Uri uri, final int requiredSize) 
            throws FileNotFoundException {
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(c.getContentResolver().openInputStream(uri), null, o);

        int width_tmp = o.outWidth
                , height_tmp = o.outHeight;
        int scale = 1;

        while(true) {
            if(width_tmp / 2 < requiredSize || height_tmp / 2 < requiredSize)
                break;
            width_tmp /= 2;
            height_tmp /= 2;
            scale *= 2;
        }

        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(c.getContentResolver().openInputStream(uri), null, o2);
    }

【讨论】：

你能解释一下requiredSize参数是什么意思吗？

【解决方案2】：

参考这个LINK

使用：Bitmap.createScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter)

或者使用这些方法::

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;

    // create a matrix for the manipulation
    Matrix matrix = new Matrix();

    // resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);

    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);

    return resizedBitmap;
}

【讨论】：

我应该在以下之后调用该方法吗：Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);