Android 切换卡（TabWidget）(2)

源代码：
package com.yarin.Android.TestOnWidget;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.TabActivity;
import android.content.DialogInterface;
import android.graphics.Color;
import android.os.Bundle;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;

public class mytestWidget extends TabActivity
{
    //声明TabHost对象
    TabHost mTabHost;
  
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
      
        //取得TabHost对象
        mTabHost = getTabHost();
      
      
        //新建一个newTabSpec(newTabSpec)
        //设置其标签和图标(setIndicator)
        //设置内容(setContent)
        mTabHost.addTab(mTabHost.newTabSpec("tab_test1")
                .setIndicator("TAB 1",getResources().getDrawable(R.drawable.img1))
                .setContent(R.id.textview1));
        mTabHost.addTab(mTabHost.newTabSpec("tab_test2")
                .setIndicator("TAB 2",getResources().getDrawable(R.drawable.img2))
                .setContent(R.id.textview2));
        mTabHost.addTab(mTabHost.newTabSpec("tab_test3")
                .setIndicator("TAB 3",getResources().getDrawable(R.drawable.img3))
                .setContent(R.id.textview3));
      
        //设置TabHost的背景颜色
        mTabHost.setBackgroundColor(Color.argb(150, 22, 70, 150));
        //设置TabHost的背景图片资源
        //mTabHost.setBackgroundResource(R.drawable.bg0);
      
        //设置当前显示哪一个标签
        mTabHost.setCurrentTab(0);
      
        //标签切换事件处理，setOnTabChangedListener
        mTabHost.setOnTabChangedListener(new OnTabChangeListener()
        {
            // TODO Auto-generated method stub
            @Override
            public void onTabChanged(String tabId)
            {
                    Dialog dialog = new AlertDialog.Builder(mytestWidget.this)
                            .setTitle("提示")
                            .setMessage("当前选中："+tabId+"标签")
                            .setPositiveButton("确定",
                            new DialogInterface.OnClickListener()
                            {
                                public void onClick(DialogInterface dialog, int whichButton)
                                {
                                    dialog.cancel();
                                }
                            }).create();//创建按钮
            
                    dialog.show();
            }          
        });
    }
}