Android实战教程第二篇之简单实现两种进度条效果

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:orientation="vertical"  android:layout_width="fill_parent"  android:layout_height="fill_parent"  > <TextView  android:layout_width="fill_parent"  android:layout_height="wrap_content"  android:text="@string/hello"  /> <ProgressBar  android:id="@+id/firstBar"  style="?android:attr/progressBarStyleHorizontal"  android:layout_width="200dp"  android:layout_height="wrap_content"  android:visibility="gone"  /> <ProgressBar  android:id="@+id/secondBar"  style="?android:attr/progressBarStyle"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:visibility="gone"  /> <Button  android:id="@+id/myButton"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:text="begin"  /> </LinearLayout> 

package ydl.progressbar;  import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ProgressBar;  public class ProgressBarTest extends Activity {  /** Called when the activity is first created. */  //声明变量  private ProgressBar firstBar =null;  private ProgressBar secondBar = null;  private Button myButton = null;  private int i = 0 ;  @Override  public void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);   //根据控件的ID来取得代表控件的对象   firstBar = (ProgressBar)findViewById(R.id.firstBar);   secondBar = (ProgressBar)findViewById(R.id.secondBar);   myButton = (Button)findViewById(R.id.myButton);   myButton.setOnClickListener(new ButtonListener());  }  class ButtonListener implements OnClickListener{      @Override   public void onClick(View v) {    if(i == 0)    {     //设置进度条处于可见的状态     firstBar.setVisibility(View.VISIBLE);     firstBar.setMax(150);//手动设置最大值，默认是100     secondBar.setVisibility(View.VISIBLE);    }    else if ( i < firstBar.getMax()){     //设置主进度条的当前值     firstBar.setProgress(i);     //设置第二进度条的当前值     firstBar.setSecondaryProgress(i + 10);     //因为默认的进度条无法显示进行的状态     //secondBar.setProgress(i);         }    else{     //设置进度条处于不可见状态     firstBar.setVisibility(View.GONE);     secondBar.setVisibility(View.GONE);    }    i = i + 10 ;   }     }   }