Fragment实现底部Tab，切换可保存状态

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" >

    <FrameLayout
        android:id="@+id/mHomeContainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/mRadioGroup" >
    </FrameLayout>

    <RadioGroup
        android:id="@+id/mRadioGroup"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:layout_alignParentBottom="true"
        android:background="@drawable/main_bottom_bg"
        android:orientation="horizontal" >

        <ImageView
            android:id="@+id/Tab_Conversation"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:contentDescription="@null"
            android:src="@drawable/skin_tab_icon_conversation_selected" />

        <ImageView
            android:id="@+id/Tab_Contact"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:contentDescription="@null"
            android:src="@drawable/skin_tab_icon_contact_normal" />

        <ImageView
            android:id="@+id/Tab_Plugin"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:contentDescription="@null"
            android:src="@drawable/skin_tab_icon_plugin_normal" />
    </RadioGroup>

</RelativeLayout>

 关键代码：

import com.lidroid.xutils.ViewUtils;
import com.lidroid.xutils.view.annotation.ContentView;
import com.lidroid.xutils.view.annotation.ViewInject;
import com.lidroid.xutils.view.annotation.event.OnClick;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.Window;
import android.widget.ImageView;
import android.content.Context;
import android.os.Bundle;

@ContentView(R.layout.activity_main)
public class MainActivity extends ActionBarActivity {

    @ViewInject(R.id.Tab_Conversation)
    private ImageView Tab_Conversation;
    @ViewInject(R.id.Tab_Contact)
    private ImageView Tab_Contact;
    @ViewInject(R.id.Tab_Plugin)
    private ImageView Tab_Plugin;

    private FragmentConversation mFragmentConversation;
    private FragmentContact mFragmentContact;
    private FragmentPlugin mFragmentPlugin;
    private Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        ViewUtils.inject(this);
        mContext = this;
        InitFragment();
        getSupportFragmentManager().beginTransaction()
                .add(R.id.mHomeContainer, mFragmentConversation).commit();
    }

    private void InitFragment() {
        mFragmentConversation = new FragmentConversation();
        mFragmentContact = new FragmentContact();
        mFragmentPlugin = new FragmentPlugin();
    }

    /**
     * 隐藏其他所有Fragment
     */
    private void HideOtherFragments(Fragment fragment) {
        if (getSupportFragmentManager().getFragments() == null) {
            return;
        }
        for (Fragment fm : getSupportFragmentManager().getFragments()) {
            if (fm != fragment) {
                getSupportFragmentManager().beginTransaction().hide(fm)
                        .commit();
            }
        }
    }

    /**
     * Tab切换
     * 
     * @param view
     */
    @OnClick({ R.id.Tab_Conversation, R.id.Tab_Contact, R.id.Tab_Plugin })
    private void OnTabSelected(View view) {
        ClearSelection();
        FragmentTransaction mTransaction = getSupportFragmentManager()
                .beginTransaction();
        switch (view.getId()) {
        case R.id.Tab_Conversation:
            Tab_Conversation.setImageDrawable(getResources().getDrawable(
                    R.drawable.skin_tab_icon_conversation_selected));
            if (!getSupportFragmentManager().getFragments().contains(
                    mFragmentConversation)) {
                mTransaction.add(R.id.mHomeContainer, mFragmentConversation);
            }
            mTransaction.show(mFragmentConversation);
            HideOtherFragments(mFragmentConversation);
            break;
        case R.id.Tab_Contact:
            Tab_Contact.setImageDrawable(getResources().getDrawable(
                    R.drawable.skin_tab_icon_contact_selected));
            if (!getSupportFragmentManager().getFragments().contains(
                    mFragmentContact)) {
                mTransaction.add(R.id.mHomeContainer, mFragmentContact);
            }
            mTransaction.show(mFragmentContact);
            HideOtherFragments(mFragmentContact);
            break;
        case R.id.Tab_Plugin:
            Tab_Plugin.setImageDrawable(getResources().getDrawable(
                    R.drawable.skin_tab_icon_plugin_selected));
            if (!getSupportFragmentManager().getFragments().contains(
                    mFragmentPlugin)) {
                mTransaction.add(R.id.mHomeContainer, mFragmentPlugin);
            }
            mTransaction.show(mFragmentPlugin);
            HideOtherFragments(mFragmentPlugin);
            break;
        default:
            break;
        }
        mTransaction.commit();
    }

    /**
     * 清除所有选中状态
     */
    private void ClearSelection() {
        Tab_Conversation.setImageDrawable(getResources().getDrawable(
                R.drawable.skin_tab_icon_conversation_normal));
        Tab_Contact.setImageDrawable(getResources().getDrawable(
                R.drawable.skin_tab_icon_contact_normal));
        Tab_Plugin.setImageDrawable(getResources().getDrawable(
                R.drawable.skin_tab_icon_plugin_normal));
    }

}