Android中繪制圓角矩形圖片及任意形狀圖片

圓角矩形圖片在蘋果的產品中很流行，相比於普通的矩形，很多人都喜歡圓角矩形的圖片，因為它避開了直角的生硬，帶來更好的用戶體驗，下面是幾個設計的例子：

下面在Android中實現將普通的矩形圖片繪制成圓角矩形。首先看最終效果：

代碼清單：

1. package com.example.phototest;
3. import android.os.Bundle;
4. import android.app.Activity;
5. import android.graphics.Bitmap;
6. import android.graphics.BitmapFactory;
7. import android.graphics.Canvas;
8. import android.graphics.Color;
9. import android.graphics.Paint;
10. import android.graphics.Path;
11. import android.graphics.PorterDuffXfermode;
12. import android.graphics.PorterDuff;
13. import android.graphics.RectF;
14. import android.graphics.drawable.BitmapDrawable;
15. import android.graphics.drawable.Drawable;
16. import android.view.Menu;
17. import android.widget.ImageView;
19. public class MainActivity extends Activity {
21. private ImageView myImageView;
22. @Override
23. public void onCreate(Bundle savedInstanceState) {
24. super.onCreate(savedInstanceState);
25. setContentView(R.layout.activity_main);
26. myImageView=(ImageView)findViewById(R.id.imageView1);
27. Bitmap photo = BitmapFactory.decodeResource(getResources(), R.drawable.photo1);
28. myImageView.setImageBitmap(createFramedPhoto(500,400,photo,20));
29. //myImageView.setImageBitmap(createStarPhoto(500,400,photo));
30. }
32. @Override
33. public boolean onCreateOptionsMenu(Menu menu) {
34. getMenuInflater().inflate(R.menu.activity_main, menu);
35. return true;
36. }
37. private Bitmap createFramedPhoto(int x, int y, Bitmap image, float outerRadiusRat) {
38. //根據源文件新建一個darwable對象
39. Drawable imageDrawable = new BitmapDrawable(image);
41. // 新建一個新的輸出圖片
42. Bitmap output = Bitmap.createBitmap(x, y, Bitmap.Config.ARGB_8888);
43. Canvas canvas = new Canvas(output);
45. // 新建一個矩形
46. RectF outerRect = new RectF(0, 0, x, y);
48. // 產生一個紅色的圓角矩形
49. Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
50. paint.setColor(Color.RED);
51. canvas.drawRoundRect(outerRect, outerRadiusRat, outerRadiusRat, paint);
54. // 將源圖片繪制到這個圓角矩形上
55. //詳解見http://lipeng88213.iteye.com/blog/1189452
56. paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
57. imageDrawable.setBounds(0, 0, x, y);
58. canvas.saveLayer(outerRect, paint, Canvas.ALL_SAVE_FLAG);
59. imageDrawable.draw(canvas);
60. canvas.restore();
62. return output;
63. }
64. }