Fragment的隐藏与显示

package com.bwie.helpdemo;

import com.bwie.fragment.BillFrag;
import com.bwie.fragment.IndexFrag;
import com.bwie.fragment.TaskFrag;

import android.os.Bundle;
import android.app.Activity;
import android.content.SharedPreferences;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class IndexActivity extends FragmentActivity implements OnClickListener {

    private Button index_bill;
    private TextView index_home;
    private TextView index_task;

    private IndexFrag indexFrag;
    private BillFrag billFrag;
    private TaskFrag taskFrag;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_index);
        
        // 找控件
        findView();

        // 为布局添加fragment,开启事物
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction tran = fm.beginTransaction();

        indexFrag = new IndexFrag();
        billFrag = new BillFrag();
        taskFrag = new TaskFrag();
        //R.id.relative为布局
        tran.add(R.id.relative, indexFrag, "index").show(indexFrag)
        .add(R.id.relative, billFrag, "bill").hide(billFrag)
        .add(R.id.relative, taskFrag, "task").hide(taskFrag);

        tran.commit();

        // 为按钮设置点击监听
        index_bill.setOnClickListener(this);
        index_home.setOnClickListener(this);
        index_task.setOnClickListener(this);
    }

    private void findView() {
        index_bill = (Button) findViewById(R.id.index_bill);
        index_home = (TextView) findViewById(R.id.index_home);
        index_task = (TextView) findViewById(R.id.index_task);

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.index_bill:
            // 获取事物
            FragmentManager fm_1 = getSupportFragmentManager();
            FragmentTransaction tran_0 = fm_1.beginTransaction();
            tran_0.show(billFrag).hide(indexFrag).hide(taskFrag).commit();

            break;

        case R.id.index_home:
            FragmentManager fm_2 = getSupportFragmentManager();
            FragmentTransaction tran_1 = fm_2.beginTransaction();
            tran_1.show(indexFrag).hide(billFrag).hide(taskFrag).commit();

            break;
        case R.id.index_task:
            FragmentManager fm_3 = getSupportFragmentManager();
            FragmentTransaction tran_2 = fm_3.beginTransaction();
            tran_2.show(taskFrag).hide(billFrag).hide(indexFrag).commit();
            break;
        }

    }
}