Android学习笔记——ProgressBar

package com.example.progressbar;

import android.app.Activity;

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

public class MainActivity extends Activity {
    
    //申明限量
    private ProgressBar firstBar = null;
    private ProgressBar secondBar = null;
    private Button myButton = null;
    private int i = 0;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_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());
        System.out.print(firstBar.getMax());
    }
    
    class ButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if(i == 0)
            {    
                //设置进度条处于可见的状态
                firstBar.setVisibility(View.VISIBLE);
                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;
        }

    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <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"
        android:max="200"
        />

    <Button
        android:id="@+id/myButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="begin"
        />
    
    
</LinearLayout>