Android简单实现圆盘抽奖界面

闲来无事，做了一个简单的抽奖转盘的ui实现，供大家参考

package com.microchange.lucky; 
 
import android.content.context; 
import android.graphics.canvas; 
import android.graphics.color; 
import android.graphics.paint; 
import android.graphics.rectf; 
import android.util.attributeset; 
import android.util.log; 
import android.view.motionevent; 
import android.view.view; 
 
public class halfcircle extends view { 
 
 private paint paint; 
 private rectf oval; 
 private float startangle; 
 private float sweepspeed; 
 private float sweepangle; 
 boolean usecenter; 
 int count;// 等份 
 @override 
 protected void ondraw(canvas canvas) { 
  setsweepangle(count); 
  while (startangle <= 360) { 
   if (startangle % (count*3) == 0) { 
    paint.setcolor(color.blue); 
   } else if (startangle % (count*2) == 0){ 
    paint.setcolor(color.green); 
   }else { 
    paint.setcolor(color.red); 
   } 
   log.e(""+startangle, paint.getcolor()+""); 
   canvas.drawarc(oval, startangle, sweepangle, usecenter, paint); 
   startangle += count; 
  } 
  float centerx = oval.centerx(); 
  float centery = oval.centery(); 
  paint.setcolor(color.white); 
//  paint.setstrokewidth(5); 
//  paint.setstyle(paint.style.stroke); //设置空心 
  paint.setantialias(true); //消除锯齿 
  canvas.drawcircle(centerx, centery, 50, paint); 
  string text = "奖"; 
  paint.settextsize(20 * getcontext().getresources().getdisplaymetrics().density); 
  float measuretext = paint.measuretext(text); 
  float texty = paint.descent() - paint.ascent(); 
  paint.setcolor(color.red); 
//  canvas.drawline(0, centery, 480, centery, paint); 
//  canvas.drawtext(text, centerx-(measuretext/2), centery, paint); 
  canvas.drawtext(text, centerx-(measuretext/2), centery+(texty/4), paint); 
 } 
 
 private void init() { 
  paint = new paint(); 
  paint.setcolor(color.blue); 
  paint.setantialias(true); 
  paint.setstrokewidth(5); 
 } 
 
 @override 
 public boolean ontouchevent(motionevent event) { 
  return super.ontouchevent(event); 
 } 
  
  
 /** 
  * @return the count 
  */ 
 public int getcount() { 
  return count; 
 } 
 
 /** 
  * @param count the count to set 
  */ 
 public void setcount(int count) { 
  this.count = 360 / count; 
 } 
 
 public paint getpaint() { 
  return paint; 
 } 
 
 public void setpaint(paint paint) { 
  this.paint = paint; 
 } 
 
 public rectf getoval() { 
  return oval; 
 } 
 
 public void setoval(rectf oval) { 
  this.oval = oval; 
 } 
 
 public float getstartangle() { 
  return startangle; 
 } 
 
 public void setstartangle(float startangle) { 
  this.startangle = startangle; 
 } 
 
 public float getsweepspeed() { 
  return sweepspeed; 
 } 
 
 public void setsweepspeed(float sweepspeed) { 
  this.sweepspeed = sweepspeed; 
 } 
 
 public float getsweepangle() { 
  return sweepangle; 
 } 
 
 public void setsweepangle(float sweepangle) { 
  this.sweepangle = sweepangle; 
 } 
 
 public boolean isusecenter() { 
  return usecenter; 
 } 
 
 public void setusecenter(boolean usecenter) { 
  this.usecenter = usecenter; 
 } 
 
 public halfcircle(context context, attributeset attrs, int defstyle) { 
  super(context, attrs, defstyle); 
  init(); 
 } 
 
 public halfcircle(context context, attributeset attrs) { 
  this(context, attrs, 0); 
 } 
 
 public halfcircle(context context) { 
  this(context, null, 0); 
 } 
 
} 

package com.microchange.lucky; 
 
import android.app.activity; 
import android.graphics.rectf; 
import android.os.bundle; 
import android.view.animation.accelerateinterpolator; 
import android.view.animation.animation; 
import android.view.animation.decelerateinterpolator; 
import android.view.animation.interpolator; 
import android.view.animation.rotateanimation; 
 
public class mainactivity extends activity { 
 rectf rect; 
 int radius = 300; 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
  super.oncreate(savedinstancestate); 
  halfcircle circle = new halfcircle(getapplicationcontext()); 
  circle.setoval(getrectf()); 
//  circle.setstartangle(90); 
  circle.setusecenter(true); 
  circle.setcount(9); 
  animation animation = new rotateanimation(0, 135*10, getrectf().centerx(), getrectf().centery()); 
  animation.setduration(5000); 
  animation.setinterpolator(new decelerateinterpolator()); 
//  animation.setrepeatcount(-1); 
  circle.setanimation(animation ); 
//  animation.start(); 
  setcontentview(circle); 
 } 
 
 public rectf getrectf(){ 
  if (rect==null){ 
//   getwindow().getdecorview().getwidth() 
   int width = getresources().getdisplaymetrics().widthpixels; 
   int height = getresources().getdisplaymetrics().heightpixels; 
   int top = (height - radius)/2; 
   int left = (width - radius)/2; 
   rect = new rectf(left, top, left+radius, top+radius); 
  } 
  return rect; 
 } 
} 

希望本文所述对大家学习android程序设计有所帮助。