为什么我TabHost不能设置当前页面

是这样的，我从3个tab里的第2个tab点击跳到一个activity，当这个activity点back的时候，然后就把之前的tab页面刷新下（就是把第2个tab切换到第3个tab）。但是
mTabHost.setCurrentTab(event.getTabPage());设置不了

这事TabHost界面的点击时间

 case R.id.to_personal:
            Intent intent = new Intent(this, PersonalActivity.class);
            startActivity(intent);
            break;

 package com.zftpay.paybox.view;

import com.niufu.paybox.R;
import com.zftpay.paybox.activity.BaseFragmentActivity;
import com.zftpay.paybox.activity.FragmentHome.CurrentTabState;
import com.zftpay.paybox.model.Events.CurrentTabStatePage;

import android.os.Bundle;
import android.view.KeyEvent;
import de.greenrobot.event.EventBus;

public class PersonalActivity extends BaseFragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_personal);
    }
    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK) {
            finish();
            EventBus.getDefault().post(new CurrentTabStatePage(CurrentTabState.FRAGMENTACQUIRER.tabPage));
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
}

这事activity点back后返回到之前界面的EventBus响应代码

 public void onEventMainThread(CurrentTabStatePage event) {
        mTabHost.setCurrentTab(event.getTabPage());
    }

http://jingyan.baidu.com/article/77b8dc7fea4f0e6174eab619.html