我正在通过编写游戏来学习 Android,并且在图形 API 方面遇到问题。
我想将图像绘制成路径的形状,然后在路径上添加边框。我能够使用路径剪辑图像,但找不到在其上添加边框的方法。我认为这很简单,因为 API 支持 Canvas.draw* 方法上的 Paint 对象。
Update
在原来的问题中,我的路径包含两个矩形,@christopher-souvey 回答正确。然而,在处理添加一个 ClipPath() 方法时,我遇到了另一个问题。
我通过在路径中添加一个圆圈来更新之前的代码。这是我的新代码:
Bitmap srcImage = BitmapFactory.decodeStream(getAssets().open("panda.jpg"));
Bitmap bitmapResult = Bitmap.createBitmap(srcImage.getWidth(), srcImage.getHeight(), Bitmap.Config.ARGB_8888);
Path path = new Path();
// This is my border
Paint paint = new Paint();
paint.setStyle(Style.STROKE);
paint.setColor(Color.RED);
paint.setStrokeWidth(2);
paint.setAntiAlias(true);
Canvas canvas = new Canvas(bitmapResult);
// Overlay two rectangles
path.addRect(10, 10, 70, 70, Path.Direction.CCW);
path.addRect(40, 40, 120, 120, Path.Direction.CCW);
canvas.drawPath(path , paint);
canvas.clipPath(path, Region.Op.INTERSECT);
path.reset();
path.addCircle(40, 80, 20, Path.Direction.CCW);
canvas.drawPath(path , paint);
canvas.clipPath(path, Region.Op.DIFFERENCE);
// The image is drawn within the area of two rectangles and a circle
// Although I suppose that puting Paint object into drawBitmap() method will add a red border on result image but it doesn't work
canvas.drawBitmap(srcImage, 0, 0, paint);
((ImageView)this.findViewById(R.id.imageView1)).setImageBitmap(bitmapResult);
这是我的代码的结果:https://i.stack.imgur.com/8j2Kg.png https://i.stack.imgur.com/8j2Kg.png
这就是我所期望的:https://i.stack.imgur.com/iKhIr.png https://i.stack.imgur.com/iKhIr.png
我是否错过了任何让它发挥作用的东西?