BitMap 设置图片大小

Bitmap bitMap = BitmapFactory.decodeFile(path);
       int width = bitMap.getWidth();

       int height = bitMap.getHeight();

       // 设置想要的大小

       int newWidth = 500;

       int newHeight = 400;

       // 计算缩放比例

       float scaleWidth = ((float) newWidth) / width;

       float scaleHeight = ((float) newHeight) / height;

       // 取得想要缩放的matrix参数

       Matrix matrix = new Matrix();

       matrix.postScale(scaleWidth, scaleHeight);

       // 得到新的图片

       bitMap = Bitmap.createBitmap(bitMap, 0, 0, width, height, matrix,

       true);