Android：如何以编程方式仅舍入位图的顶角？ [英] Android: how to programmatically round only top corners of a bitmap?

问题描述

我目前正在使用此代码：

I'm currently using this code:

@Override
public Bitmap transform(Bitmap source) {
    Bitmap result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(result);

    final int color = 0xff424242;
    final Paint paint = new Paint();
    final Rect rect = new Rect(0, 0, source.getWidth(),source.getHeight());
    final RectF rectF = new RectF(rect);

    final float scale = context.getResources().getDisplayMetrics().density;
    final float roundDp = 10 * scale;

    paint.setAntiAlias(true);
    canvas.drawARGB(0, 0, 0, 0);
    paint.setColor(color);
    canvas.drawRoundRect(rectF, roundDp, roundDp, paint);

    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
    canvas.drawBitmap(source, rect, rect, paint);
    source.recycle();
    return result;
}

但问题是这种方法只允许我修改所有4个角落一旦。我如何只围绕图像的底角？

But the problem is that this method only allows me to modify all 4 corners at once. How would I round only the bottom corners of the image?

推荐答案

以下是您的答案： https://stackoverflow.com/a/5252726/1969801

public static Bitmap getRoundedCornerBitmap(Context context, Bitmap input, int pixels , int w , int h , boolean squareTL, boolean squareTR, boolean squareBL, boolean squareBR  ) {

Bitmap output = Bitmap.createBitmap(w, h, Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final float densityMultiplier = context.getResources().getDisplayMetrics().density;

final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, w, h);
final RectF rectF = new RectF(rect);

//make sure that our rounded corner is scaled appropriately
final float roundPx = pixels*densityMultiplier;

paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);


//draw rectangles over the corners we want to be square
if (squareTL ){
    canvas.drawRect(0, 0, w/2, h/2, paint);
}
if (squareTR ){
    canvas.drawRect(w/2, 0, w, h/2, paint);
}
if (squareBL ){
    canvas.drawRect(0, h/2, w/2, h, paint);
}
if (squareBR ){
    canvas.drawRect(w/2, h/2, w, h, paint);
}

paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(input, 0,0, paint);

return output;
 }

和onDraw功能：

 @Override
 protected void onDraw(Canvas canvas) {
//super.onDraw(canvas);
    Drawable drawable = getDrawable();

    Bitmap b =  ((BitmapDrawable)drawable).getBitmap() ;
    Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

    int w = getWidth(), h = getHeight();


    Bitmap roundBitmap =  CropImageView.getRoundedCornerBitmap( getContext(), bitmap,10 , w, h , true, false,true, false);
    canvas.drawBitmap(roundBitmap, 0,0 , null);
}

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