Android编程开发之在Canvas中利用Path绘制基本图形(圆形,矩形,椭圆,三角形等)

本文实例讲述了Android编程开发之在Canvas中利用Path绘制基本图形的方法。分享给大家供大家参考，具体如下：

在Android中绘制基本的集合图形，本程序就是自定义一个View组件，程序重写该View组件的onDraw(Canvase)方法，然后在该Canvas上绘制大量的基本的集合图形。

直接上代码：

1.自定义的View组件代码：

package com.infy.configuration;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.LinearGradient;import android.graphics.Paint;import android.graphics.Path;import android.graphics.RectF;import android.graphics.Shader;import android.util.AttributeSet;import android.view.View;public class MyView extends View{    public MyView(Context context, AttributeSet attrs) {      super(context, attrs);    }    @Override    protected void onDraw(Canvas canvas) {      // TODO Auto-generated method stub      super.onDraw(canvas);      //把整张画布绘制成白色      canvas.drawColor(Color.WHITE);      Paint paint = new Paint();      //去锯齿      paint.setAntiAlias(true);      paint.setColor(Color.BLUE);      paint.setStyle(Paint.Style.STROKE);      paint.setStrokeWidth(3);      //绘制圆形      canvas.drawCircle(40, 40, 30, paint);      //绘制正方形      canvas.drawRect(10, 80, 70, 140, paint);      //绘制矩形      canvas.drawRect(10, 150, 70, 190, paint);      RectF rel = new RectF(10,240,70,270);      //绘制椭圆      canvas.drawOval(rel, paint);      //定义一个Path对象，封闭一个三角形      Path path1 = new Path();      path1.moveTo(10, 340);      path1.lineTo(70, 340);      path1.lineTo(40, 290);      path1.close();      //根据Path进行绘制，绘制三角形      canvas.drawPath(path1, paint);      //定义一个Path对象，封闭一个五角星      Path path2 = new Path();      path2.moveTo(27, 360);      path2.lineTo(54, 360);      path2.lineTo(70, 392);      path2.lineTo(40, 420);      path2.lineTo(10, 392);      path2.close();      //根据Path进行绘制，绘制五角星      canvas.drawPath(path2, paint);      //设置填丛风格后进行绘制      paint.setStyle(Paint.Style.FILL);      paint.setColor(Color.RED);      canvas.drawCircle(120, 40, 30, paint);      //绘制正方形      canvas.drawRect(90, 80, 150, 140, paint);      //绘制矩形      canvas.drawRect(90, 150, 150, 190, paint);      //绘制圆角矩形      RectF re2 = new RectF(90,200,150,230);      canvas.drawRoundRect(re2, 15, 15, paint);      //绘制椭圆      RectF re21 = new RectF(90, 240, 150, 270);      canvas.drawOval(re21, paint);      Path path3 = new Path();      path3.moveTo(90, 340);      path3.lineTo(150, 340);      path3.lineTo(120, 290);      path3.close();      //绘制三角形      canvas.drawPath(path3,paint);      //绘制五角形      Path path4 = new Path();      path4.moveTo(106, 360);      path4.lineTo(134, 360);      path4.lineTo(150, 392);      path4.lineTo(120, 420);      path4.lineTo(90, 392);      path4.close();      canvas.drawPath(path4, paint);      //设置渐变器后绘制      //为Paint设置渐变器      Shader mShasder = new LinearGradient(0, 0, 40, 60, new int[]{Color.RED,Color.GREEN,Color.BLUE,Color.YELLOW}, null, Shader.TileMode.REPEAT);      paint.setShader(mShasder);      //设置阴影      paint.setShadowLayer(45, 10, 10, Color.GRAY);      //绘制圆形      canvas.drawCircle(200, 40, 30, paint);      //绘制正方形      canvas.drawRect(170, 80, 230, 140, paint);      //绘制矩形      canvas.drawRect(170, 150, 230, 190, paint);      //绘制圆角的矩形      RectF re31 = new RectF();      canvas.drawRoundRect(re31, 15, 15, paint);      //绘制椭圆      RectF re32 =new RectF();      canvas.drawOval(re32, paint);      //根据Path,绘制三角形      Path path5 = new Path();      path5.moveTo(170, 340);      path5.lineTo(230, 340);      path5.lineTo(200, 290);      path5.close();      canvas.drawPath(path5, paint);      //根据PAth,进行绘制五角形      Path path6 = new Path();      path6.moveTo(186, 360);      path6.lineTo(214, 360);      path6.lineTo(230, 392);      path6.lineTo(200, 420);      path6.lineTo(170, 392);      path6.close();      canvas.drawPath(path6, paint);    }}

2. 使用一个基本的Activity来实现自定义的MyView组件，

定义一个ZiDingYiViewTes的Activity：

package com.infy.configuration;import android.app.Activity;import android.os.Bundle;public class ZiDingYiViewTes extends Activity{    private MyView myView =null;    @Override    protected void onCreate(Bundle savedInstanceState) {      // TODO Auto-generated method stub      super.onCreate(savedInstanceState);      myView = new MyView(this, null);      setContentView(myView);    }}

Android的Canvas既可以绘制简单的集合图形，也可以直接将一个Bitmap绘制到画布上。
最后附上效果图(多了一个椭圆)：

希望本文所述对大家Android程序设计有所帮助。

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