Java 如何使用OnTabChangeListener？

我有一个有3个标签的android程序。当我点击“地图选项卡”时，我希望它显示“地图已选定”消息，如下图所示。但是，如果我点击“名称”选项卡，然后第二次返回“地图选项卡”，屏幕上将不会显示“再次选择地图”消息。如何使“地图”选项卡在每次选择该选项卡时显示“再次选择地图”消息？您能否编辑以下代码并用示例演示如何使用OnTabChangeListener

public class MapsActivity extends MapActivity implements OnTabChangeListener {    

@Override
public void onCreate(Bundle savedInstanceState)
{ 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main4);
    Toast.makeText(getApplicationContext(),"Map is Selected", Toast.LENGTH_LONG).show();        
}

public void onTabChanged(String tabId) {
    Toast.makeText(getApplicationContext(),"Map Selected Again", Toast.LENGTH_LONG).show(); 
}

@Override
protected boolean isRouteDisplayed() {
    return false;
} }

更新。但是下面的方法不输出消息

`public class HelloTabWidget extends TabActivity implements OnTabChangeListener{`

    private TabHost mTabHost;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Resources res = getResources(); 
        TabHost tabHost = getTabHost();  
        TabHost.TabSpec spec;  
        Intent intent; 

        intent = new Intent().setClass(this, BarActivity.class);
        spec = tabHost.newTabSpec("Name").setIndicator("Name",res.getDrawable(R.drawable.ic_tab_name)).setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, CityActivity.class);
        spec = tabHost.newTabSpec("city").setIndicator("City",res.getDrawable(R.drawable.ic_tab_city)).setContent(intent); 
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, MapsActivity.class);
        spec = tabHost.newTabSpec("Map").setIndicator("Map",res.getDrawable(R.drawable.ic_tab_map)).setContent(intent);
        tabHost.addTab(spec);        

        tabHost.setCurrentTab(2);
    }

    public void onTabChanged(String tabId) {
        mTabHost = getTabHost();
        mTabHost.setOnTabChangedListener(this);
        Toast.makeText(getApplicationContext(), "To check for Display", Toast.LENGTH_LONG).show();
        Log.i("selected tab index", "Current index - "+ mTabHost.getCurrentTab());      
    }} 

---

您应该对TabActivity类而不是选项卡的内容实现

OnTabChangeListener

在TabActivity中实现OnTabChangeListener

然后为TabHost

mTabHost.setOnTabChangedListener设置侦听器（此选项）

更新

public class HelloTabWidget extends TabActivity implements OnTabChangeListener{`

    private TabHost mTabHost;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Resources res = getResources(); 
        TabHost tabHost = getTabHost();  
        TabHost.TabSpec spec;  
        Intent intent; 
        mTabHost = getTabHost();


        intent = new Intent().setClass(this, BarActivity.class);
        spec = tabHost.newTabSpec("Name").setIndicator("Name",res.getDrawable(R.drawable.ic_tab_name)).setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, CityActivity.class);
        spec = tabHost.newTabSpec("city").setIndicator("City",res.getDrawable(R.drawable.ic_tab_city)).setContent(intent); 
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, MapsActivity.class);
        spec = tabHost.newTabSpec("Map").setIndicator("Map",res.getDrawable(R.drawable.ic_tab_map)).setContent(intent);
        tabHost.addTab(spec);        

        tabHost.setCurrentTab(2);
        mTabHost.setOnTabChangedListener(this);
    }

    public void onTabChanged(String tabId) {
        Toast.makeText(getApplicationContext(), "Selected Tab "+tabId, Toast.LENGTH_LONG).show();
        Log.i("selected tab index", "Current index - "+ mTabHost.getCurrentTab());      
    }} 

@Lalith Poptani非常感谢您的详细回答。你能看看我上面的最新问题，告诉我这样做是否正确吗？
public class HelloTabWidget extends TabActivity implements OnTabChangeListener{`

    private TabHost mTabHost;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Resources res = getResources(); 
        TabHost tabHost = getTabHost();  
        TabHost.TabSpec spec;  
        Intent intent; 
        mTabHost = getTabHost();


        intent = new Intent().setClass(this, BarActivity.class);
        spec = tabHost.newTabSpec("Name").setIndicator("Name",res.getDrawable(R.drawable.ic_tab_name)).setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, CityActivity.class);
        spec = tabHost.newTabSpec("city").setIndicator("City",res.getDrawable(R.drawable.ic_tab_city)).setContent(intent); 
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, MapsActivity.class);
        spec = tabHost.newTabSpec("Map").setIndicator("Map",res.getDrawable(R.drawable.ic_tab_map)).setContent(intent);
        tabHost.addTab(spec);        

        tabHost.setCurrentTab(2);
        mTabHost.setOnTabChangedListener(this);
    }

    public void onTabChanged(String tabId) {
        Toast.makeText(getApplicationContext(), "Selected Tab "+tabId, Toast.LENGTH_LONG).show();
        Log.i("selected tab index", "Current index - "+ mTabHost.getCurrentTab());      
    }}