选择时选项卡背景发生变化

Question

我需要在不同状态下设置不同的图像作为选项卡背景。我已将一张图像设置为默认背景，但如何在选择选项卡时切换到另一张图像。下面是我的代码。

public class HelloTabWidget extends  TabActivity {            

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Resources res = getResources(); // Resource object to get Drawables    
        TabHost tabHost = getTabHost();  // The activity TabHost    
        TabHost.TabSpec spec;  // Resusable TabSpec for each tab    
        Intent intent;  // Reusable Intent for each tab
        TabWidget tw = getTabWidget(); 


        for (int i = 0; i < tw.getChildCount(); i++) { 
                    View v = tw.getChildAt(i); 
                    v.setBackgroundDrawable(getResources().getDrawable 
        (R.drawable.tab_artist)); 
                  } 



        //First tab
        intent = new Intent().setClass(this, FirstActivity.class);    // Initialize a TabSpec for each tab and add it to the TabHost    
        spec = tabHost.newTabSpec("First").setIndicator("First")
        .setContent(intent);    
        tabHost.addTab(spec);
        getTabHost().getTabWidget().getChildAt(0).setBackgroundResource(R.drawable.tabselected);

         //Second tab
         intent = new Intent().setClass(this, SecondActivity.class);    // Initialize a TabSpec for each tab and add it to the TabHost    
            spec = tabHost.newTabSpec("Second").setIndicator("Second")
            .setContent(intent);    
            tabHost.addTab(spec);
             getTabHost().getTabWidget().getChildAt(1).setBackgroundResource(R.drawable.tabselected);

             //third
             intent = new Intent().setClass(this, ThirdActivity.class);    // Initialize a TabSpec for each tab and add it to the TabHost    
                spec = tabHost.newTabSpec("Third").setIndicator("Third")
                .setContent(intent);    
                tabHost.addTab(spec);
                getTabHost().getTabWidget().getChildAt(2).setBackgroundResource(R.drawable.tabselected);

    }
}

/*tab_artist.xml*/

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">    
<!-- When selected, use grey -->    
<item android:background="@drawable/tabselected"  android:state_selected="true" />    
<!-- When not selected, use white-->    
<item android:background="@drawable/tabunselected" />
</selector>

Answer 1

public class HelloTabWidget extends  TabActivity implements OnTabChangeListener{  
.....

mTabHost. setOnTabChangedListener(this);

@Override
    public void onTabChanged(String tabId) {

              // Here in tabId you will get the name of the Tab from that you can check and set the background 
                // of the requirement tab according to need.
    }
}

Answer 2

实现 onTabChangeListener() 并修改它们的背景。干杯

http://developer.android.com/reference/android/widget/ TabHost.OnTabChangeListener.html

编辑：
使用 tabHost 来实现该方法。您可以在任何您想要的地方实施。假设在设置所有 TabWidget 后执行此操作。最好的做法是使用选项卡的 id，就像将它们设置为“第一”、“第二”等。

 tabHost.setOnTabChangedListener(new OnTabChangeListener(){
          @Override
            public void onTabChanged(String tabId) {
                        if(tabId.equals("First"){
                                //do something
                        }else if(tabId.equals("Second"))
                        {
                            //do something
                        }// etc etc etc


                        }});

Answer 3

这可能对你有帮助

Tabhost.setOnTabChangedListener(new OnTabChangeListener(){
@Override
        public void onTabChanged(String tabId) {

            for(int i=0;i<tb.getTabWidget().getChildCount();i++)
            {
                   tb.getTabWidget().getChildAt(i).setBackgroundResource(R.drawable.tabunselected); //unselected
            }
            tb.getTabWidget().getChildAt(tb.getCurrentTab()).setBackgroundResource(R.drawable.tabselected); 
}});