如何从TabHost中引用一个子activity来调用一个公共函数？

在TabHost中有两个子activity，这两个子activity在两个tab中。在其中的一个activity实现了一个公共函数，我想从父类TabHost中调用这个函数，来触发tab中的一些action。
能否从TabHost中引用activity本身来调用一个公共函数？
tabhost设置：

res = getResources(); 
    tabHost = getTabHost(); 

    TabHost.TabSpec spec; 
    Intent intent;  

    intent = new Intent().setClass(this, home.class);
    spec = tabHost.newTabSpec("home").setIndicator("Groups", res.getDrawable(R.drawable.groups)).setContent(intent);
    tabHost.addTab(spec);
    intent = new Intent().setClass(this, messages.class);
    spec = tabHost.newTabSpec("messages").setIndicator("Messages", res.getDrawable(R.drawable.messages)).setContent(intent);    
    tabHost.addTab(spec);

是之前遇见过这个问题是这样解决的：
1.在manifest文件中设置intent filter
2.给子activity添加嵌套的'listener'
3.在子activity的onResume()/onPause()到register/unregister监听器
4.在TabActivity创建intent，然后广播。
AndroidManifest.xml

<activity
    android:name=".MyActivity"
    android:label="@string/app_name"
    <intent-filter>
        <action android:name="com.mycompany.myApp.DO_SOMETHING" />
    </intent-filter>
</activity>

MyActivity.java

public class MyActivity extends Activity {

    private MyListener listener = null;
    private Boolean MyListenerIsRegistered = false;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreated(savedInstanceState);

        listener = new MyListener();
    }

    @Override
    protected void onResume() {
        super.onResume();


        if (!MyListenerIsRegistered) {
            registerReceiver(listener, new IntentFilter("com.mycompany.myApp.DO_SOMETHING"));
            MyListenerIsRegisterd = true;
        }
    }

    @Override
    protected void onPause() {
        super.onPause();

        if (MyListenerIsRegistered) {
            unregisterReceiver(listener);
            MyListenerIsRegistered = false;
        }
    }

    // Nested 'listener'
    protected class MyListener extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {

            // No need to check for the action unless the listener will
            // will handle more than one - let's do it anyway
            if (intent.getAction().equals("com.mycompany.myApp.DO_SOMETHING")) {
                // Do something
            }
        }
    }
}

main TabActivity

private void MakeChildDoSomething() {

    Intent i = new Intent();
    i.setAction("com.mycompany.myApp.DO_SOMETHING");
    sendBroadcast(i);
}

希望能帮你解决问题：

 Activity currentActivity = getLocalActivityManager().getActivity(_TabHost.getCurrentTabTag());
    if(currentActivity != null && currentActivity instanceof iMyActivity)
    {
    // 传递给子类
    ((iMyActivity)currentActivity).onLaunchDelegate();
    }