在Android开发中通过自定义View实现一个圆形进度条

发布时间：2020-11-25 17:19:19 作者：Leah
来源：亿速云阅读：148

这期内容当中小编将会给大家带来有关在Android开发中通过自定义View实现一个圆形进度条，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。

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。

上述就是小编为大家分享的在Android开发中通过自定义View实现一个圆形进度条了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注亿速云行业资讯频道。

在Android开发中通过自定义View实现一个圆形进度条

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