本文实例讲述了Android编程实现类似于圆形ProgressBar的进度条效果。分享给大家供大家参考，具体如下：

我们要实现一个类似于小米分享中的圆形播放进度条，android自带的圆形ProgressBar是默认自动旋转的，所以无法实现，于是我们想到了使用自定义一个View，来实现这种效果。

首先来看看自己定义的View

package cn.easymobi.application.bell.common;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.view.View;public class ProgressView extends View{ private float fArcNum; private float fMax; private float density; public float getDensity() { return density; } public void setDensity(float density) { this.density = density; } public ProgressView(Context context) { super(context); } public ProgressView(Context context,AttributeSet attrs) { super(context,attrs); } protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub super.onDraw(canvas); Paint paint=new Paint(); if(fArcNum>0) { paint.setColor(Color.GRAY); paint.setFlags(Paint.ANTI_ALIAS_FLAG); canvas.drawCircle(40*density/2, 40*density/2, 40*density/2, paint); } paint.setColor(Color.YELLOW); paint.setFlags(Paint.ANTI_ALIAS_FLAG); //paint.setStrokeWidth(2); RectF rect=new RectF(0, 0, 40*density, 40*density); canvas.drawArc(rect, -90, fArcNum,true, paint); paint.setColor(Color.BLACK); paint.setFlags(Paint.ANTI_ALIAS_FLAG); canvas.drawCircle(40*density/2, 40*density/2, 40*density/2-5, paint); } public void setProgress(float num) { fArcNum = (num/fMax) * 360; } public float getfArcNum() { return fArcNum; } public void setfArcNum(float fArcNum) { this.fArcNum = fArcNum; } public float getfMax() { return fMax; } public void setfMax(float fMax) { this.fMax = fMax; }}

我们通过重写View的onDraw方法，根据fArcNum好fMax来判断当前播放到的位置，然后不停的刷新改View就实现了这个效果。至于画弧，是采用了drawArc方法，然后通过在其内部画圆遮盖多余部分实现。

下面是MediaPlayer与该View的同步处理，核心代码如下

// *******************************************************************// Func: playAudio//// by: Sun// 2011.9.1// *******************************************************************public void playAudio(final String path, final ProgressBar pb) { Thread thread = new Thread(new Runnable() { public void run() { try { if (mpMediaPlayer != null) { mpMediaPlayer.stop(); mpMediaPlayer.release(); mpMediaPlayer = null; } mpMediaPlayer = new MediaPlayer(); mpMediaPlayer.setDataSource(path); mpMediaPlayer.prepare(); mpMediaPlayer.setOnPreparedListener(new OnPreparedListener() { public void onPrepared(MediaPlayer mp) { pb.setVisibility(ProgressBar.GONE); frontPv.setfMax(mpMediaPlayer.getDuration()); frontPv.setProgress(0); mpMediaPlayer.start(); refrash = new Thread(new Runnable() { public void run() { try { while (frontPv.getfArcNum() <= 360 && mpMediaPlayer.isPlaying()) { if (bIsOver) break; frontPv.setProgress(mpMediaPlayer.getCurrentPosition()); Thread.sleep(1000); mHandle.sendEmptyMessage(MSG_REFRESH_UI); } mHandle.sendEmptyMessage(MSG_PLAY_OVER); } catch (Exception e) { e.printStackTrace(); } } }); refrash.start(); } }); } catch (Exception e) { e.printStackTrace(); } } }); thread.start();}

其中frontPv是我们自己定义的view,最后发送handler是调用invalidate方法刷新该 view,mpMediaPlayers是我们定义的MediaPlayer对象。我们通过在进程中每隔一秒更新frontPv当中的fArcNum并且 刷新实现转动的动画效果。

更多关于Android相关内容感兴趣的读者可查看本站专题：《Android开发入门与进阶教程》、《Android调试技巧与常见问题解决方法汇总》、《Android多媒体操作技巧汇总(音频,视频,录音等)》、《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》及《Android控件用法总结》

希望本文所述对大家Android程序设计有所帮助。