Fragment实现TabHost标签切换功能

首先定义四个布局文件分别表示切换的四个界面

fragment1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="我是第一个fragment" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="得到第四个Fragment中EditText的值" />

</LinearLayout>

fragment2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="我是第二个fragment" />

    <DatePicker
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

fragment3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="我是第三个fragment" />

    <RatingBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

fragment4.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="我是第四个fragment" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

定义一个主布局文件来装纳四个切换的界面

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <LinearLayout
        android:id="@+id/linearlayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#000000"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/btn1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="A" />

        <Button
            android:id="@+id/btn2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="B" />

        <Button
            android:id="@+id/btn3"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="C" />

        <Button
            android:id="@+id/btn4"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="D" />
    </LinearLayout>

    <FrameLayout
        android:id="@+id/framelayout"
        android:layout_below="@id/linearlayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    </FrameLayout>

</RelativeLayout>

创建四个类Fragment1，Fragment2，Fragment3，Fragment4，

分别表示四个界面的操作类。

Fragment2 ，Fragment3和Fragment4只是简单的返回其对应的布局文件视图，这里不做介绍。

Fragment2.java

package com.example.myfragment;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment2 extends Fragment {

	@Override
	public void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		View view = inflater.inflate(R.layout.fragment2, null);
		return view;
	}

	@Override
	public void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
	}

}

Fragment3.java

package com.example.myfragment;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment3 extends Fragment {

	@Override
	public void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		View view = inflater.inflate(R.layout.fragment3, null);
		return view;
	}

	@Override
	public void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
	}

}

Fragment4.java

package com.example.myfragment;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment4 extends Fragment {

	@Override
	public void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		View view = inflater.inflate(R.layout.fragment4, null);
		return view;
	}

	@Override
	public void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
	}

}

Fragment1主要是获取Fragment4里EditText的值并显示出来。

通过getFragmentManager().findFragmentByTag("fragment4");取得fragment4对象，

并通过fragment4.getView().findViewById(R.id.editText1);获得EditText控件，显示里面的值。

Fragment1.java

package com.example.myfragment;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Fragment1 extends Fragment {

	private Button button;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		View view = inflater.inflate(R.layout.fragment1, null);
		button = (Button) view.findViewById(R.id.button1);
		button.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				//得到fragment4对象
				Fragment4 fragment4 = (Fragment4) getFragmentManager().findFragmentByTag("fragment4");
				//取得fragment4中的editText控件，并得到里面的值
				EditText editText = (EditText) fragment4.getView().findViewById(R.id.editText1);
				Toast.makeText(getActivity(), "第四个Fragment中EditText的值为：\n"+editText.getText(),
						Toast.LENGTH_LONG).show();
			}
		});
		return view;
	}

	@Override
	public void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
	}

}

主界面实现类

MainActivity.java

package com.example.myfragment;

import android.os.Bundle;
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;

public class MainActivity extends FragmentActivity implements OnClickListener {

	private Button btn1;//标签按钮1
	private Button btn2;//标签按钮2
	private Button btn3;//标签按钮3
	private Button btn4;//标签按钮4
	private FragmentManager manager;
	private FragmentTransaction transaction;
	private Fragment1 fragment1;//页面1
	private Fragment2 fragment2;//页面2
	private Fragment3 fragment3;//页面3
	private Fragment4 fragment4;//页面4

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//通过manager得到transaction对象
		manager = getSupportFragmentManager();
		transaction = manager.beginTransaction();
		//创建四个Fragment对象并将其添加到transaction中
		fragment1 = new Fragment1();
		//第一个参数表示要添加到某个布局上（id）
		//第二个参数表示要添加的Fragment
		//第三个设置标签
		transaction.add(R.id.framelayout, fragment1, "fragment1");
		//默认显示第一个页面，其他的都隐藏起来
		fragment2 = new Fragment2();
		transaction.add(R.id.framelayout, fragment2, "fragment2").hide(fragment2);
		fragment3 = new Fragment3();
		transaction.add(R.id.framelayout, fragment3, "fragment3").hide(fragment3);
		fragment4 = new Fragment4();
		transaction.add(R.id.framelayout, fragment4, "fragment4").hide(fragment4);
		//提交
		transaction.commit();
		btn1 = (Button) findViewById(R.id.btn1);
		btn2 = (Button) findViewById(R.id.btn2);
		btn3 = (Button) findViewById(R.id.btn3);
		btn4 = (Button) findViewById(R.id.btn4);
		btn1.setOnClickListener(this);
		btn2.setOnClickListener(this);
		btn3.setOnClickListener(this);
		btn4.setOnClickListener(this);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		//将全部Fragment页面都隐藏起来
		transaction = manager.beginTransaction();
		transaction.hide(fragment1).hide(fragment2).hide(fragment3).hide(fragment4);
		//然后显示你所点击的那个按钮所对应的Fragment
		switch (v.getId()) {
		case R.id.btn1:
			transaction.show(fragment1);
			break;
		case R.id.btn2:
			transaction.show(fragment2);
			break;
		case R.id.btn3:
			transaction.show(fragment3);
			break;
		case R.id.btn4:
			transaction.show(fragment4);
			break;
		}
		//提交
		transaction.commit();
	}

}

MyFragmentTab截图