canvas.clipRect

clipRect(float left, float top, float right, float bottom)
Intersect the current clip with the specified rectangle, which is expressed in local coordinates.

只有在这个区域内的才显示，其他所有内容好像被裁剪掉了一样，不显示。

 

[java] view plaincopy

1. public void onDraw(Canvas canvas)  
2. {  
3. super.onDraw(canvas);  
4. /* 设置画布的颜色 */  
5. canvas.drawColor(Color.BLACK);  
6. /* 设置取消锯齿效果 */  
7. mPaint.setAntiAlias(true);  
8. //mPaint.setStyle(Paint.Style.STROKE);  
9. mPaint.setColor(Color.RED);  
10. //canvas.save();  
11. // 设置裁剪区域  
12. //canvas.drawRect(new Rect(1, 1, 320, 400),mPaint);  
13. canvas.clipRect(40, 40, 280, 260);  
14. canvas.drawColor(Color.GRAY);  
15. /* 线锁定画布 */  
16. canvas.save();  
17. /* 旋转画布,顺时针旋转“画布”，以左上角为圆心 */  
18. canvas.rotate(45.0f);  
19. //canvas.drawRect(new Rect(40, 40, 280, 260),mPaint);  
20. /* 设置颜色及绘制矩形 */  
21. mPaint.setColor(Color.RED);  
22. canvas.drawRect(new Rect(45,45,140,100), mPaint);  
23. /* 解除画布的锁定 */  
24. canvas.restore();  
25. /* 设置颜色及绘制另一个矩形 */  
26. mPaint.setColor(Color.GREEN);  
27. canvas.drawRect(new Rect(150,75,260,120), mPaint);  
28. }  

 

 

[java] view plaincopy

1. public void onDraw(Canvas canvas)  
2. {  
3.     super.onDraw(canvas);  
4.   
5.     /* 设置画布的颜色 */  
6.     canvas.drawColor(Color.BLACK);  
7.   
8.     /* 设置取消锯齿效果 */  
9.     mPaint.setAntiAlias(true);  
10.     mPaint.setStyle(Paint.Style.STROKE);//空心，不填充  
11.     mPaint.setColor(Color.RED);  
12.     /* 线锁定画布 */  
13.     canvas.save();  
14.     //整个屏幕加个边框  
15.     canvas.drawRect(new Rect(1, 1, 320, 400),mPaint);  
16.     //这里不用clipRect，而改为drawRect，仅模拟裁剪的区域，而不真正裁剪  
17.     canvas.drawRect(new Rect(40, 40, 280, 260),mPaint);  
18.   
19.     /* 旋转画布 */  
20.     canvas.rotate(45.0f);  
21.     //旋转后的屏幕边框  
22.     canvas.drawRect(new Rect(1, 1, 320, 400),mPaint);  
23.     //裁剪框旋转后的weizhi  
24.     canvas.drawRect(new Rect(40, 40, 280, 260),mPaint);  
25.   
26.     /* 设置颜色及绘制矩形 */  
27.     mPaint.setColor(Color.RED);  
28.     canvas.drawRect(new Rect(45,45,140,100), mPaint);  
29.   
30.     /* 解除画布的锁定 */  
31.     canvas.restore();  
32.   
33.     /* 设置颜色及绘制另一个矩形 */  
34.     mPaint.setColor(Color.GREEN);  
35.     canvas.drawRect(new Rect(150,75,260,120), mPaint);  
36. }