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：
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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：
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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。
