android 高仿圆形菜单

看见一个人写了一个圆形的可以转的菜单，当时看的还是挺模糊的，最后自己模仿的写了一遍，这是源代码

基本思想是这样的

1，把每个图标显示的什么图标确定下来

2，计算每一个点的坐标，

3，在activity就可以正确显示出了

4，当我们移动图标的时候，计算出移动后的图标的角度，知道角度和半径就可以设置它的坐标啊，以它为起始图标，画出剩下的图标

5，实在很模糊，不理解的再议论

启动的Activity

1.import Android.app.Activity; 
2.import android.os.Bundle;  3. 
4.public class Main extends Activity { 

 5.    /** Called when the activity is first created. */ 

 6.    @Override

  7.    public void onCreate(Bundle savedInstanceState) { 

8.        super.onCreate(savedInstanceState); 

9.        setContentView(new CircleMenuActivity(getApplicationContext(), 150, 150, 100));  10.    } 
11.} 
菜单生成的类

1.package rw.circle; 
2. 
3. 
4.import android.content.Context;

  5.import android.graphics.Bitmap;

  6.import android.graphics.BitmapFactory; 

7.import android.graphics.Canvas; 

8.import android.graphics.Color; 

9.import android.graphics.Paint; 

10.import android.util.Log; 

11.import android.view.MotionEvent; 

 12.import android.view.View; 

14.public class CircleMenuActivity extends View { 

16.private Paint paint=new Paint(); 

 17.private SeeView[] seeViews; 

18.private static final int MenuCount=6;//桌面图标的个数

   19.private int pointX=0,pointY=0;//圆心坐标

   20.private static final int radius=150;//半径 

  21.private int DegreeOfPoint;//两个点之间的角度 

  22.    public CircleMenuActivity(Context context, int x, int y,int radiu) { 

 23.        super(context); 

24.        paint.setColor(Color.GREEN); 
25.        paint.setStrokeWidth(2); 

 26.        setBackgroundResource(R.drawable.tt1); 
27.        pointX=x; 
28.        pointY=y; 
29.        radiu=radius; 
30.        SetPoint(); 
31.        CalculateCoordinate(); 
32.        // TODO Auto-generated constructor stub  

 33.    } 
34.    /* 35.     * 这个函数是设置每一个点
36.     */ 
37.   private void SetPoint() { 

 38.        // TODO Auto-generated method stub  

 39.        seeViews=new SeeView[MenuCount]; 

 40.        //SeeView seeView;  

41.        int angle=0; 

 42.        DegreeOfPoint=360/MenuCount; 

43.        for (int i = 0; i <MenuCount; i++) { 

44.            seeViews[i]=new SeeView(); 

45.            seeViews[i].angle=angle; 
46.            seeViews[i].bitmap=BitmapFactory.decodeResource(getResources(),R.drawable.t1+i); 
47.            angle+=DegreeOfPoint; 
48.        } 
49.    } 
50.   private void resetPointAngle(float x,float y){ 

51.       int angle=CalculateAngle(x, y);

  52.       for (int i = 0; i < MenuCount; i++) { 

53.        seeViews[i].angle=angle; 
54.        angle+=DegreeOfPoint; 
55.    } 
56.   } 
57.   //计算坐标   58.   private void CalculateCoordinate(){ 

 59.       SeeView seeView; 
60.       for (int i = 0; i < MenuCount; i++) {

  61.        seeView=seeViews[i]; 
62.        seeView.x=pointX+(float)(radius*Math.cos(seeView.angle*Math.PI/180)); 

63.        seeView.y=pointY+(float)(radius*Math.sin(seeView.angle*Math.PI/180)); 

 64.    } 
65.   } 
66.   private int CalculateAngle(float x,float y) { 

 67.    float distance=(float)Math.sqrt((x-pointX)*(x-pointX)+(y-pointY)*(y-pointY));

  68.    int degree=(int)(Math.acos((x-pointX)/distance)*180/Math.PI); 

69.    if (y<pointY) { 

70.        degree=-degree; 
71.    } 
72.    return degree; 

73.} 
74.    
75.    public boolean dispatchTouchEvent(MotionEvent event) { 

 76.        // TODO Auto-generated method stub 

  77.        //Animation animation;  

78.        //animation=AnimationUtils.loadAnimation(getContext(), R.anim.scale);  

79.        resetPointAngle(event.getX(), event.getY()); 
80.        CalculateCoordinate();   
81.        invalidate(); 
82.        return true; 

83.    } 
84.     
85.     
86.    protected void onDraw(Canvas canvas) { 

87.        // TODO Auto-generated method stub  

88.        canvas.drawPoint(pointX, pointY, paint); 
89.        for (int i = 0; i < MenuCount; i++) { 

 90.            if (!seeViews[i].isVisible)  

91.                continue; 

92.            drawIncenter(canvas, seeViews[i].bitmap, seeViews[i].x, seeViews[i].y); 
93.        } 
94.        super.onDraw(canvas); 

95.    } 
96.     
97.private void drawIncenter(Canvas canvas,Bitmap bitmap,float left,float top) 

98.{ 
99.    canvas.drawPoint(left, top, paint); 
100.    Log.i("-------->", left+""); 

 101.    Log.i("----------------->", bitmap.getWidth()/2+""); 

102.    Log.i("----------------------->", left-bitmap.getWidth()/2+""); 

103.    canvas.drawBitmap(bitmap, left+bitmap.getWidth()/2, top+bitmap.getHeight()/2,null);

  104.} 
105.private class SeeView{ 

  106.       Bitmap bitmap;//每个图标的图  

107.       float x,y;//每个图标的坐标  

108.       int angle;//角度  

109.       boolean isVisible=true;//是否可见，当然可见，要不怎么看见  

110.   } 
111.}