Android进度条ProgressBar的实现代码

<?xml version="1.0" encoding="utf-8"?> 
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:app="http://schemas.android.com/apk/res-auto" 
  xmlns:tools="http://schemas.android.com/tools" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  tools:context="com.amy.processbartest.MainActivity"> 
 
  <!--水平进度条 --> 
  <ProgressBar 
    android:id="@+id/progressBar1" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:max="100" 
    style="@android:style/Widget.ProgressBar.Horizontal" /> 
 
  <!-- 圆形进度条 --> 
  <ProgressBar 
    android:id="@+id/progressBar2" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    style="?android:attr/progressBarStyleLarge"/> 
 
</android.support.constraint.ConstraintLayout> 

package com.amy.processbartest; 
 
import android.os.Handler; 
import android.os.Message; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.ProgressBar; 
import android.widget.Toast; 
 
import static android.R.attr.id; 
 
public class MainActivity extends AppCompatActivity { 
 
  //定义水平进度条 
  private ProgressBar horizonP; 
  //定义圆形进度条 
  private ProgressBar circleP; 
  //完成进度 
  private int mProcessStatus = 0; 
  //声明一个用于处理消息的Handler类的对象 
  private Handler mHandler; 
 
  /** 
   * 在主活动onCreate方法中，首先获得水平进度条和圆形进度条， 
   * 然后通过匿名内部类实例化处理消息的Handler类的对象，并重写其handlerMessage方法， 
   * 实现当好吃操作没有完成时更新进度，否则设置进度条不显示。 
   * @param savedInstanceState 
   */ 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    horizonP = (ProgressBar) findViewById(R.id.progressBar1); 
    circleP = (ProgressBar) findViewById(R.id.progressBar2); 
    mHandler = new Handler(){ 
      @Override 
      public void handleMessage(Message msg) { 
        if (msg.what == 0x111) { 
          horizonP.setProgress(mProcessStatus);//更新进度 
        } else { 
          Toast.makeText(MainActivity.this,"耗时操作已经完成",Toast.LENGTH_SHORT).show(); 
          horizonP.setVisibility(View.GONE); 
          circleP.setVisibility(View.GONE); 
        } 
      } 
    }; 
 
    //开个线程用语模拟耗时操作 
    new Thread(new Runnable() { 
      @Override 
      public void run() { 
        while (true) { 
          mProcessStatus = doWork();//获取耗时操作完成的百分比 
          Message msg = new Message(); 
          if (mProcessStatus<100) { 
            msg.what = 0x111; 
            mHandler.sendMessage(msg);//发送消息 
          } else { 
            msg.what = 0x110; 
            mHandler.sendMessage(msg);//发送消息 
            break; 
          } 
        } 
      } 
      //模拟一个耗时操作 
      private int doWork() { 
        mProcessStatus += Math.random()*10;//改变完成进度 
        try { 
          Thread.sleep(200);//每隔200毫秒进度改变一次 
        } catch (InterruptedException e) { 
          e.printStackTrace(); 
        } 
        return mProcessStatus;//返回新的进度 
      } 
    }).start();//开启一个新的线程 
 
  } 
}