<转载>Android通过onDraw实现在View中绘图操作

01.public class AndroidTest extends Activity {
02.    /** Called when the activity is first created. */
03.    @Override
04.    public void onCreate(Bundle savedInstanceState) {
05.        super.onCreate(savedInstanceState);
06.
07.        MyView mv = new MyView(this);
08.        setContentView(mv);
09.    }
10.
11.    public class MyView extends View {
12.
13.        MyView(Context context) {
14.            super(context);
15.        }
16.
17.        @Override
18.        protected void onDraw(Canvas canvas) {
19.            // TODO Auto-generated method stub
20.            super.onDraw(canvas);
21.
22.            // 首先定义一个paint
23.            Paint paint = new Paint();
24.
25.            // 绘制矩形区域-实心矩形
26.            // 设置颜色
27.            paint.setColor(Color.BLUE);
28.            // 设置样式-填充
29.            paint.setStyle(Style.FILL);
30.            // 绘制一个矩形
31.            canvas.drawRect(new Rect(0, 0, getWidth(), getHeight()), paint);
32.
33.            // 绘空心矩形
34.            // 设置颜色
35.            paint.setColor(Color.RED);
36.            // 设置样式-空心矩形
37.            paint.setStyle(Style.STROKE);
38.            // 绘制一个矩形
39.            canvas.drawRect(new Rect(10, 10, 100, 30), paint);
40.
41.            // 绘文字
42.            // 设置颜色
43.            paint.setColor(Color.GREEN);
44.            // 绘文字
45.            canvas.drawText("Hello", 10, 50, paint);
46.
47.            // 绘图
48.            // 从资源文件中生成位图
49.            Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon);
50.            // 绘图
51.            canvas.drawBitmap(bitmap, 10, 60, paint);
52.        }
53.
54.    }
55.}