Android调整位图大小保持纵横比
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Android resize bitmap keeping aspect ratio
提问by Zbarcea Christian
I have a custom view (1066 x 738), and I am passing a bitmap image (720x343). I want to scale the bitmap to fit in the custom view without exceeding the bound of the parent.
我有一个自定义视图 (1066 x 738)，我正在传递一个位图图像 (720x343)。我想缩放位图以适应自定义视图而不超出父级的边界。
I want to achieve something like this:
我想实现这样的目标：
How should I calculate the bitmap size?
我应该如何计算位图大小？
How I calculate the new width/height:
我如何计算新的宽度/高度：
public static Bitmap getScaledBitmap(Bitmap b, int reqWidth, int reqHeight)
{
int bWidth = b.getWidth();
int bHeight = b.getHeight();
int nWidth = reqWidth;
int nHeight = reqHeight;
float parentRatio = (float) reqHeight / reqWidth;
nHeight = bHeight;
nWidth = (int) (reqWidth * parentRatio);
return Bitmap.createScaledBitmap(b, nWidth, nHeight, true);
}
But all I am achieving is this:
但我所取得的成就是：
回答by matiash
You should try using a transformation matrix built for ScaleToFit.CENTER. For example:
您应该尝试使用为ScaleToFit.CENTER. 例如：
Matrix m = new Matrix();
m.setRectToRect(new RectF(0, 0, b.getWidth(), b.getHeight()), new RectF(0, 0, reqWidth, reqHeight), Matrix.ScaleToFit.CENTER);
return Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), m, true);
