底部菜单栏 Fragment + button 键切换

1，实现接口setOnClickListener 重写里面onClick 方法 

2，设置点击事件

3，用switch  获取控件ID 。设置点击事件。

【1】布局：

<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/ll_layout"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:orientation="vertical" >

    </LinearLayout>



    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:layout_alignParentBottom="true"

        android:orientation="horizontal" >



        <Button

            android:id="@+id/btn_wx"

            android:layout_width="0dp"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="微信" />



        <Button

            android:id="@+id/btn_contact"

            android:layout_width="0dp"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="通讯录" />



        <Button

            android:id="@+id/btn_disconver"

            android:layout_width="0dp"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="发现" />



        <Button

            android:id="@+id/btn_me"

            android:layout_width="0dp"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="我" />

    </LinearLayout>



</RelativeLayout>

【2】代码：

public class MainActivity extends Activity implements OnClickListener {



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        // [1]找到控件

        Button btn_contact = (Button) findViewById(R.id.btn_contact);

        Button btn_disconver = (Button) findViewById(R.id.btn_disconver);

        Button btn_me = (Button) findViewById(R.id.btn_me);

        Button btn_wx = (Button) findViewById(R.id.btn_wx);

        // [2]设置点击事件

        btn_contact.setOnClickListener(this);

        btn_disconver.setOnClickListener(this);

        btn_me.setOnClickListener(this);

        btn_wx.setOnClickListener(this);

        

    }



    @Override

    public void onClick(View v) {

        //[2.1]获取fragment的管理者

        FragmentManager fragmentManager = getFragmentManager();

        FragmentTransaction beginTransaction = fragmentManager.beginTransaction();

        

        // [3]具体判断一下点击的是哪个按钮

        switch (v.getId()) {

        case R.id.btn_wx:   //点击微信按钮 动态替换fragment

            beginTransaction.replace(R.id.ll_layout, new WxFragment());

            

            break;



        case R.id.btn_contact:

            beginTransaction.replace(R.id.ll_layout, new ContactFragment());



            break;

        case R.id.btn_disconver:

            beginTransaction.replace(R.id.ll_layout, new DiscoverFragment());

            break;



        case R.id.btn_me:

            beginTransaction.replace(R.id.ll_layout, new MeFragment());

            break;

        }

        //[4]最后一步记得commit

beginTransaction.commit();



    }



}