绘制几何图形——使用android.graphics类

大神在这------>：http://www.cnblogs.com/stulife/archive/2010/08/19/1803313.html

package com.example.demo;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Path;
import android.graphics.Shader;
import android.graphics.LinearGradient;

public class GraphicesActivity extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		/* 设置ContentView为自定义的MyVieW */
		MyView myView = new MyView(this);
		setContentView(myView);
	}

	/* 自定义继承View 的MyView */
	private class MyView extends View {
		public MyView(Context context) {
			super(context);
		}

		/* 重写onDraw（） */
		@Override
		protected void onDraw(Canvas canvas) {
			super.onDraw(canvas);
			/* 设置背景为白色 */
			canvas.drawColor(Color.WHITE);
			Paint paint = new Paint();
			/* 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 */
			paint.setStyle(Paint.Style.STROKE);
			/* 设置paint的外框宽度 */
			paint.setStrokeWidth(3);
			/* 画一个空心圆形 */
			canvas.drawCircle(40, 40, 30, paint);
			/* 画一个空心正方形 */
			canvas.drawRect(10, 90, 70, 150, paint);
			/* 画一个空心长方形 */
			canvas.drawRect(10, 170, 70, 200, paint);
			/* 画一个空心椭圆形 */
			RectF re = new RectF(10, 220, 70, 250);
			canvas.drawOval(re, paint);
			/* 画一个空心三角形 */
			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style为 FILL：实心 */
			paint.setStyle(Paint.Style.FILL);
			/* 设置paint的颜色 */
			paint.setColor(Color.BLUE);
			/* 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);
			/* 画一个实心长方形 */
			canvas.drawRect(90, 170, 150, 200, paint);
			/* 画一个实心椭圆 */
			RectF re2 = new RectF(90, 220, 150, 250);
			canvas.drawOval(re2, paint);
			/* 画一个实心三角形 */
			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);

			/* 画一个渐变色圆 */
			canvas.drawCircle(200, 40, 30, paint);
			/* 画一个渐变色正方形 */
			canvas.drawRect(170, 90, 230, 150, paint);
			/* 画一个渐变色长方形 */
			canvas.drawRect(170, 170, 230, 200, paint);
			/* 画一个渐变色椭圆 */
			RectF re3 = new RectF(170, 220, 230, 250);
			canvas.drawOval(re3, paint);
			/* 画一个渐变色三角形 */
			Path path4 = new Path();
			path4.moveTo(170, 330);
			path4.lineTo(230, 330);
			path4.lineTo(200, 270);
			path4.close();
			canvas.drawPath(path4, paint);
			/* 画一个渐变色梯形 */
			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);
		}
	}
}

完整代码：http://download.youkuaiyun.com/detail/yegucheng2618/7645551