Path类可以预先在View上将N个点连成一条"路径",然后调用Canvas的drawPath(path,paint)即可沿着路径绘制图形

Android还为路径绘制提供了PathEffect来定义绘制效果,PathEffect包含如下子类

ComposePathEffect

CornerPathEffect

DashPathEffect

DiscretePathEffect

PathDashPathEffect

SumPathEffect

下面的示例将会逐一使用上面的绘制效果

package WangLi.Graphics.PathTest;  import android.app.Activity;  
import android.content.Context;  
import android.graphics.Canvas;  
import android.graphics.Color;  
import android.graphics.ComposePathEffect;  
import android.graphics.CornerPathEffect;  
import android.graphics.DashPathEffect;  
import android.graphics.DiscretePathEffect;  
import android.graphics.Paint;  
import android.graphics.Path;  
import android.graphics.PathDashPathEffect;  
import android.graphics.PathEffect;  
import android.graphics.SumPathEffect;  
import android.os.Bundle;  
import android.view.View;  public class PathTest extends Activity {  /** Called when the activity is first created. */  @Override  public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(new MyView(this));  }  class MyView extends View  {  float phase;  PathEffect[] effects = new PathEffect[7];  int[] colors;  private Paint paint;  Path path;  public MyView(Context context) {  super(context);  paint = new Paint();  paint.setStyle(Paint.Style.STROKE);  paint.setStrokeWidth(4);  //创建,并初始化Path  path = new Path();  path.moveTo(0, 0);  for(int i = 1; i<= 15; i++)  {  //生成15个点,随机生成它们的坐标,并将它们连成一条Path  path.lineTo(i*20, (float)Math.random()*60);  }  //初始化七个颜色  colors = new int[] {  Color.BLACK,Color.BLUE,Color.CYAN,  Color.GREEN,Color.MAGENTA,Color.RED,Color.YELLOW  };  }  protected void onDraw(Canvas canvas)  {  //将背景填充成白色  canvas.drawColor(Color.WHITE);  //-------下面开始初始化7中路径的效果  //使用路径效果  effects[0] = null;  //使用CornerPathEffect路径效果  effects[1] = new CornerPathEffect(10);  //初始化DiscretePathEffect  effects[2] = new DiscretePathEffect(3.0f,5.0f);  //初始化DashPathEffect  effects[3] = new DashPathEffect(new float[]{20,10,5,10},phase);  //初始化PathDashPathEffect  Path p = new Path();  p.addRect(0, 0, 8, 8, Path.Direction.CCW);  effects[4] = new PathDashPathEffect(p,12,phase,PathDashPathEffect.Style.ROTATE);  //初始化PathDashPathEffect  effects[5] = new ComposePathEffect(effects[2],effects[4]);  effects[6] = new SumPathEffect(effects[4],effects[3]);  //将画布移到8,8处开始绘制  canvas.translate(8, 8);  //依次使用7中不同路径效果,7种不同的颜色来绘制路径  for(int i = 0; i < effects.length; i++)  {  paint.setPathEffect(effects[i]);  paint.setColor(colors[i]);  canvas.drawPath(path, paint);  canvas.translate(0, 60);  }  //改变phase值,形成动画效果  phase += 1;  invalidate();  }  }  
}  

效果如下