绘制几何图形

/*
 * 绘制几何图形
 */
import 略;

public class Ex07_02Activity extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		MyView myView = new MyView(this);
		setContentView(myView);
	}

	private class MyView extends View {

		public MyView(Context context) {
			super(context);
		}

		// 重写onDraw()方法
		protected void onDraw(Canvas canvas) {
			super.onDraw(canvas);
			// 设置背景为白色
			canvas.drawColor(Color.WHITE);

			Paint paint = new Paint();
			// 消去锯齿
			paint.setAntiAlias(true);
			// 设置paint的颜色
			paint.setColor(Color.RED);
			// 设置paint的style为STROKE，空心的
			paint.setStyle(Paint.Style.STROKE);
			// 设置paint的外框宽度
			paint.setStrokeWidth(3);

			// 画一个空心圆
			canvas.drawCircle(40, 40, 30, paint);
			// 画一个空心正方形
			canvas.drawRect(10, 90, 70, 150, paint);
			// 画一个空心的长方形
			canvas.drawRect(10, 170, 70, 200, paint);
			// 画一个空心的椭圆
			RectF re = new RectF(10, 220, 70, 250);
			canvas.drawOval(re, paint);
			// 画一个空心的三角形
			Path path = new Path();
			path.moveTo(10, 330);
			path.lineTo(70, 330);
			path.lineTo(40, 270);
			path.close();
			canvas.drawPath(path, paint);
			// 画一个空心梯形
			Path path1 = new Path();
			path1.moveTo(10, 410);
			path1.lineTo(70, 410);
			path1.lineTo(55, 350);
			path1.lineTo(25, 350);
			path1.close();
			canvas.drawPath(path1, paint);

			// 设置paint的颜色
			paint.setColor(Color.BLUE);
			// 设置paint的style为FILL,实心
			paint.setStyle(Paint.Style.FILL);

			// 画一个实心圆
			canvas.drawCircle(120, 40, 30, paint);
			// 画一个实心正方形
			canvas.drawRect(90, 90, 150, 150, paint);
			// 画一个实心的长方形
			canvas.drawRect(90, 170, 150, 200, paint);
			// 画一个实心的椭圆
			RectF re2 = new RectF(90, 220, 150, 250);
			canvas.drawOval(re2, paint);
			// 画一个实心的三角形
			Path path2 = new Path();
			path2.moveTo(90, 330);
			path2.lineTo(150, 330);
			path2.lineTo(120, 270);
			path2.close();
			canvas.drawPath(path2, paint);
			// 画一个实心梯形
			Path path3 = new Path();
			path3.moveTo(90, 410);
			path3.lineTo(150, 410);
			path3.lineTo(135, 350);
			path3.lineTo(105, 350);
			path3.close();
			canvas.drawPath(path3, paint);

			// 设置渐变颜色
			Shader mShader = new LinearGradient(0, 0, 100, 100, new int[] {
					Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW }, null,
					Shader.TileMode.REPEAT);
			paint.setShader(mShader);

			// 画一个渐变的圆
			canvas.drawCircle(200, 40, 30, paint);
			// 画一个渐变的正方形
			canvas.drawRect(170, 90, 230, 150, paint);
			// 画一个渐变的的长方形
			canvas.drawRect(170, 170, 230, 200, paint);
			// 画一个渐变的的椭圆
			RectF re3 = new RectF(170, 220, 230, 250);
			canvas.drawOval(re3, paint);
			// 画一个渐变的的三角形
			Path path4 = new Path();
			path4.moveTo(170, 330);
			path4.lineTo(230, 330);
			path4.lineTo(200, 270);
			path4.close();
			canvas.drawPath(path4, paint);
			// 画一个渐变的梯形
			Path path5 = new Path();
			path5.moveTo(170, 410);
			path5.lineTo(230, 410);
			path5.lineTo(215, 350);
			path5.lineTo(185, 350);
			path5.close();
			canvas.drawPath(path5, paint);

			// 写字
			paint.setTextSize(24);
			canvas.drawText(getResources().getString(R.string.str_text1), 240,
					50, paint);
			canvas.drawText(getResources().getString(R.string.str_text2), 240,
					120, paint);
			canvas.drawText(getResources().getString(R.string.str_text3), 240,
					190, paint);
			canvas.drawText(getResources().getString(R.string.str_text4), 240,
					250, paint);
			canvas.drawText(getResources().getString(R.string.str_text5), 240,
					320, paint);
			canvas.drawText(getResources().getString(R.string.str_text6), 240,
					390, paint);

		}
	}
}

下面我们来看看程序运行后的结果：