RadioButton实现底部切换的菜单

布局文件的实现代码如下:
LinearLayout 里面有两个布局FrameLayout 和RadioGroup 垂直排列。
FrameLayout里面放置fragment，radiogroup放置可以
切换fragment的按钮

<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="com.example.gacmy.maintab.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >

        <FrameLayout
            android:id="@+id/fg_content"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1" />

        <RadioGroup
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_vertical"
            android:orientation="horizontal">

            <RadioButton
                android:id="@+id/rb_shouye"
                style="@style/home_tab_bottom"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:gravity="center"
                android:onClick="onShouye"
                android:text="test1"
                android:checked="false" />

            <RadioButton
                android:id="@+id/rb_kaoqin"
                style="@style/home_tab_bottom"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:gravity="center"
                android:onClick="onKaoqin"
                android:text="test2"
              />

            <RadioButton
                android:id="@+id/rb_my"
                style="@style/home_tab_bottom"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:button="@null"
                android:gravity="center"
                android:onClick="onMy"
                android:text="test3"
              />
        RadioGroup>
    LinearLayout>

RelativeLayout>

代码实现如下:
public class MainActivity extends AppCompatActivity {

    private RadioButton rb_menu1;
    private RadioButton rb_menu2;
    private RadioButton rb_menu3;
    private Fragment fragment1;
    private Fragment fragment2;
    private Fragment fragment3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }
    private void initView() {
        rb_menu1=(RadioButton)findViewById(R.id.rb_shouye);
        rb_menu2=(RadioButton)findViewById(R.id.rb_kaoqin);
        rb_menu3=(RadioButton)findViewById(R.id.rb_my);
    }
    //切换fragment的方法。
    @SuppressLint("NewApi")
    private void setSelection(int index) {
        resetImg();
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        hideFragments(ft);
        switch (index) {
            case 0:
                rb_menu1.setCompoundDrawablesWithIntrinsicBounds(0,R.mipmap.ic_launcher, 0, 0);
                rb_menu1.setTextColor(rb_menu1.getResources().getColor(R.color.colorAccent));
                if (fragment1 == null) {
                    fragment1 = new Fragment();
                    ft.add(R.id.fg_content, fragment1);
                } else {
                    ft.show(fragment1);
                }
                break;
            case 1:

                rb_menu2.setCompoundDrawablesRelativeWithIntrinsicBounds(0,R.mipmap.ic_launcher, 0, 0);
                rb_menu2.setTextColor(rb_menu2.getResources().getColor(R.color.colorAccent));
                if (fragment2 == null) {
                    fragment2 = new Fragment();
                    ft.add(R.id.fg_content, fragment2);
                } else {
                    ft.show(fragment2);
                }
                break;
            case 2:
                rb_menu3.setCompoundDrawablesRelativeWithIntrinsicBounds(0,R.mipmap.ic_launcher, 0, 0);
                rb_menu3.setTextColor(rb_menu3.getResources().getColor(R.color.colorAccent));
                if (fragment3 == null) {
                    fragment3 = new Fragment();
                    ft.add(R.id.fg_content, fragment3);
                } else {
                    ft.show(fragment3);
                }
                break;
        }
        ft.commit();
    }

    //重置切换布局的按钮
    @SuppressLint("NewApi")
    private void resetImg() {
        rb_menu1.setCompoundDrawablesRelativeWithIntrinsicBounds(0,R.drawable.ic_photo_white_24dp, 0, 0);
        rb_menu1.setTextColor(rb_menu1.getResources().getColor(R.color.colorPrimary));

        rb_menu2.setCompoundDrawablesWithIntrinsicBounds(0,R.drawable.ic_photo_white_24dp, 0, 0);
        rb_menu2.setTextColor(rb_menu2.getResources().getColor(R.color.colorPrimary));

        rb_menu3.setCompoundDrawablesWithIntrinsicBounds(0,R.drawable.ic_photo_white_24dp, 0, 0);
        rb_menu3.setTextColor(rb_menu3.getResources().getColor(R.color.colorPrimary));
    }

    private void hideFragments(FragmentTransaction ft) {
        if (fragment1 != null) {
            ft.hide(fragment1);
        }
        if (fragment2 != null) {
            ft.hide(fragment2);
        }
        if (fragment3 != null) {
            ft.hide(fragment3);
        }
    }

    public void onShouye(View view) {
        setSelection(0);
    }

    public void onKaoqin(View view) {
        setSelection(1);
    }

    public void onMy(View view) {
        setSelection(2);
    }




}