安卓fragmentTransaction.replace不能全屏问题_湛江下暴雨

操蛋的问题，看下下面代码

package com.example.fragmenttest;

import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity implements OnClickListener {
	private FragmentManager fragmentManager;
	private FragmentTransaction fragmentTransaction;

	private TextView tv1;
	private TextView tv2;
	
	private Fragment1 f1;
	private Fragment2 f2;
	

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		f1 = new Fragment1();
		f2 = new Fragment2();

		tv1 = (TextView) findViewById(R.id.tb1);
		tv2 = (TextView) findViewById(R.id.tb2);
		tv1.setOnClickListener(this);
		tv2.setOnClickListener(this);
		
		fragmentManager = getFragmentManager();
		fragmentTransaction = fragmentManager.beginTransaction();
		fragmentTransaction.replace(R.id.content, f1);
		fragmentTransaction.commit();

	}
	
	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.tb1:
			fragmentTransaction = fragmentManager.beginTransaction();
			fragmentTransaction.replace(R.id.content, new Fragment1());
			fragmentTransaction.commit();
			break;
			
		case R.id.tb2:
			fragmentTransaction = fragmentManager.beginTransaction();
			fragmentTransaction.replace(R.id.content, new Fragment2());
			fragmentTransaction.commit();
			break;

		default:
			break;
		}

	}
}
package com.example.fragmentt