android - 如何在空 Canvas 上画圆？

Question

我想在空 Canvas 上画圆，但不知道如何做。这是我用来在我的自定义 ImageView 类中创建空 Canvas 的代码。

bmpBase = Bitmap.createBitmap(image_width, image_height, Bitmap.Config.ARGB_8888);
canvas = new Canvas(bmpBase);
Paint paint = new Paint();
paint.setColor(Color.BLUE);
canvas.drawCircle(100, 100, 30, paint);

Answer 1

试试这个，首先在您的 MainActivity 中找到您的 imageView，然后:

                drawingImageView = (ImageView)findViewById(R.id.DrawingImageView);
                Paint paint = new Paint();
                paint.setColor(Color.BLUE));
                paint.setStyle(Paint.Style.STROKE);
                paint.setStrokeWidth(15);    
                bmpBase = Bitmap.createBitmap(image_width, image_height, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(bitmap);
                canvas.drawCircle(100, 100, 30, paint);
                drawingImageView.setImageBitmap(bitmap);