Path类

实例

MainActivity.java

package com.example.pathtest;


import android.os.Bundle;
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.view.Menu;
import android.view.View;


public class MainActivity extends Activity {


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new MyView(MainActivity.this));
}


class MyView extends View{


PathEffect[] effects=new PathEffect[7];
float phase=0;
Paint paint;
int colors[];
Path path;

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

paint=new Paint();


//空心
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(4);
//创建并初始化Path
path=new Path();
path.moveTo(0, 0);
//随机生成15个点
for(int i=1;i<=15;i++){
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
};
}


@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//将背景填充为白色
canvas.drawColor(Color.WHITE);

//初始化7种路径效果

//不使用路径效果
effects[0]=null;

//使用CornerPathEffect路径效果
effects[1]=new CornerPathEffect(5);

//使用DiscretePathEffect
effects[2]=new DiscretePathEffect(3.0f, 5.0f);

//使用DashPathEffect
effects[3]=new DashPathEffect(new float[]{10,5,5,5}, phase);

//使用PathDashPathEffect
Path p=new Path();
//CCW表示逆时针
p.addRect(0, 0, 8, 8, Path.Direction.CCW);
effects[4]=new PathDashPathEffect(p, 5, phase, PathDashPathEffect.Style.MORPH);

effects[5]=new ComposePathEffect(effects[2], effects[4]);

effects[6]=new SumPathEffect(effects[4], effects[3]);

canvas.translate(8, 8);

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实现动画效果
phase+=1;
invalidate();

}
}
}