Android简易实战教程–第二话《两种进度条》

点击按钮模拟进度条下载进度，“下载”完成进度条消失。

代码如下：

xml：

<?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>

Activity：

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 ;
}    }}