常用控件（2）— ProgressBar（进度条）

PBar.java

package com.example.progressbar;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;

public class PBar extends Activity {
    
    private ProgressBar firstBar = null;
    private ProgressBar secondBar = null;
    private Button B = null;
    private int i = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pbar);
        
        firstBar = (ProgressBar) findViewById(R.id.firstBar);
        secondBar = (ProgressBar) findViewById(R.id.secondBar);
        B = (Button) findViewById(R.id.myButton);
        B.setOnClickListener(new ButtonListener());
        
        
        
    }
    class ButtonListener implements OnClickListener{

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            if(i==0){
                firstBar.setVisibility(View.VISIBLE);
                secondBar.setVisibility(View.VISIBLE);
            }
            else if(i<firstBar.getMax()){
                firstBar.setProgress(i);    //设置主进度条（深色） 播放量
                firstBar.setSecondaryProgress(i+10);  //设置次进度条（浅色）缓冲量
                //secondBar.setProgress(i);   默认进度条不会显示进度
            }
            else {
                firstBar.setVisibility(View.GONE);
                secondBar.setVisibility(View.GONE);
            }
            i+=50;
        }
        
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_pbar, menu);
        return true;
    }

}

xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
                <!--
                    设置进度条类型 
                    style="?android:attr/progressBarStyleHorizontal"
                    设置进度条不可见
                    android:visibility="gone"
                    设置进度条MAX
                    android:max="500"
                -->

    <ProgressBar
        android:id="@+id/firstBar"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:max="500"
        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>