tablhost如何使用，为什么我程序运行了之后显示已经停止响应？

package com.example.administrator.tablehost;

import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;

public class MainActivity extends TabActivity {

public TabHost host;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    host = getTabHost();
    TabHost.TabSpec ts1 = host.newTabSpec("ts1");
    ts1.setIndicator("选项卡1");
    ts1.setContent(new Intent(this, Activity1.class));
    host.addTab(ts1);

    TabHost.TabSpec ts2 = host.newTabSpec("ts2");
    ts2.setIndicator("选项卡2");
    ts2.setContent(new Intent(this, Activity2.class));
    host.addTab(ts2);
}

}

http://www.cnblogs.com/tinyphp/p/3875105.html
http://www.2cto.com/kf/201401/272333.html