带有片段和FragmentActivity的TabHost

Question

我正在研究Android应用程序,我想使用3个选项卡为每个选项卡使用Fragments进行导航,但我不知道如何创建这样做的结构.

我想分别添加每个片段,因为每个片段都不同,但我不知道在FragmentActivity中将它们添加到何处.

我有这些文件.

tabs_layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_height="match_parent"
    android:layout_width="match_parent">

    <TabHost android:id="@android:id/tabhost"
         android:layout_width="match_parent"
         android:layout_height="match_parent">

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

             <TabWidget
                android:id="@android:id/tabs" 
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
             />

             <FrameLayout
                 android:id="@android:id/tabcontent" 
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"

             >

                 <FrameLayout
                     android:id="@+id/tabRateAPet" 
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"

                 />

                 <FrameLayout
                     android:id="@+id/tabViewMyRates" 
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"

                 />

                 <FrameLayout
                     android:id="@+id/tabViewGlobalRates" 
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"

                 />


             </FrameLayout>
        </LinearLayout>
    </TabHost>
</LinearLayout>

TabsMain.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;

public class MainTabsActivity extends FragmentActivity {
public static final String RATE_A_PET = "Rate a Pet";
public static final String MY_RATES = "My Rates";
public static final String GLOBAL_RATES = "Global Rates";

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tabs_layout);
 }
}

Tabs.java

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;
import android.widget.TabHost.TabSpec;
import android.widget.TextView;

public class Tabs extends Fragment implements OnTabChangeListener {
    private static final String TAG = "FragmentTabs";
    public static final String RATE_A_PET = "Rate a Pet";
    public static final String MY_RATES = "My Rates";
    public static final String GLOBAL_RATES = "Global Rates";

    private View mRoot;
    private TabHost mTabHost;
    private int mCurrentTab;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
//      super.onCreateView(inflater, container, savedInstanceState);
        mRoot = inflater.inflate(R.layout.tabs_layout, null);
        mTabHost = (TabHost) mRoot.findViewById(android.R.id.tabhost);
        setupTabs();
        return mRoot;
    }

    private void setupTabs() {
        mTabHost.setup(); // important!
        mTabHost.addTab(newTab(RATE_A_PET, R.string.tabRateAPet, R.id.tabRateAPet));
        mTabHost.addTab(newTab(MY_RATES, R.string.tabViewMyRates, R.id.tabViewMyRates));
    }

    private TabSpec newTab(String tag, int labelId, int tabContentId) {
        Log.d(TAG, "buildTab(): tag=" + tag);

        View indicator = LayoutInflater.from(getActivity()).inflate(
                R.layout.tab,
                (ViewGroup) mRoot.findViewById(android.R.id.tabs), false);
        ((TextView) indicator.findViewById(R.id.text)).setText(labelId);

        TabSpec tabSpec = mTabHost.newTabSpec(tag);
        tabSpec.setIndicator(indicator);
        tabSpec.setContent(tabContentId);
        return tabSpec;
    }


    @Override
    public void onTabChanged(String tabId) {
        Log.d(TAG, "onTabChanged(): tabId=" + tabId);
        if (RATE_A_PET.equals(tabId)) {
            updateTab(tabId, R.id.tabRateAPet);
            mCurrentTab = 0;
            return;
        }
        if (MY_RATES.equals(tabId)) {
            updateTab(tabId, R.id.tabViewMyRates);
            mCurrentTab = 1;
            return;
        }
        if (GLOBAL_RATES.equals(tabId)) {
            updateTab(tabId, R.id.tabViewGlobalRates);
            mCurrentTab = 2;
            return;
        }
    }   
    private void updateTab(String tabId, int placeholder) {
        FragmentManager fm = getFragmentManager();
        if (fm.findFragmentByTag(tabId) == null) {
            fm.beginTransaction()
                    .replace(placeholder, new RateMyPetActivity(), tabId)
                    .commit();
        }
    }

}

Answer 1

我建议为每个选项卡创建一个单独的片段文件.我最近也做了这个,所以我在下面概述了我的代码:

布局文件

activity_main.xml中

<android.support.v4.app.FragmentTabHost
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

    <TabWidget
        android:id="@android:id/tabs"

        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0"/>

    <FrameLayout
        android:id="@android:id/tabcontent"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_weight="0"/>

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

</LinearLayout>
</android.support.v4.app.FragmentTabHost>

tab1_view.xml //使用此格式添加相应的选项卡布局(确保更改字符串变量)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
        android:orientation="vertical"
        tools:context=".DeviceFragment" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/tab1_fragment_string" />

</LinearLayout>

SRC文件

MainActivity.java //注意到在这个.addTab过程中我只使用了文本.您还可以使用需要添加到hdpi文件夹的drawable添加图标.我在这个例子中也只创建了三个选项卡.

package com.example.applicationname;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTabHost;

public class MainActivity extends FragmentActivity {
    // Fragment TabHost as mTabHost
    private FragmentTabHost mTabHost;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTabHost = (FragmentTabHost)findViewById(android.R.id.tabhost);
        mTabHost.setup(this, getSupportFragmentManager(), R.id.realtabcontent);

        mTabHost.addTab(mTabHost.newTabSpec("tab1").setIndicator("Tab1"),
            Tab1Fragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("tab2").setIndicator("Tab2"),
            Tab2Fragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("tab3").setIndicator("Tab3"),
            Tab3Fragment.class, null);
    }
}

Tab1Fragment.java //再次复制所需数量的选项卡

package com.example.applicationname;

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

public class Tab1Fragment extends Fragment  {

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View V = inflater.inflate(R.layout.tab1_view, container, false);

        return V;
    }
}

确保正确设置了R.java和strings.xml文件,然后您的选项卡应该正常运行.