我想在我的仪表板活动中创建选项卡，允许用户左右滑动以在片段（我的其他类）之间切换。但我注意到在我的应用程序中我有这个：（请注意下面的评论以查看图片）
为什么我TabHost没有显示我的标签？我正在关注教程（请注意评论以查看教程）这是我的dashboard.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:background="#3b3b3b">
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/WELCOME"
android:textSize="40dip"
android:gravity="center"
android:layout_marginTop="20dip"/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/emailTextView"/>
<Button android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/Logout_Me"
android:textSize="20dip"
android:textColor="#21dbd4"
android:textStyle="bold"
android:id="@+id/btnLogout"
android:layout_marginTop="80dip"
android:background="@null"/>
<TabHost
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TabWidget
android:id="@android:id/tabs"
android:orientation="horizontal"
android:layout_width="fill_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"/>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
/>
</LinearLayout>
</TabHost>
</LinearLayout>
如果您需要查看更多编码，请告诉我，我很乐意更新问题。
以下是java类：
MyFragment.java：
package com.example.loginandregistration;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MyFragment extends Fragment {
public static final String EXTRA_MESSAGE = "EXTRA_MESSAGE";
public static final MyFragment newInstance(String message)
{
MyFragment f = new MyFragment();
Bundle bdl = new Bundle(1);
bdl.putString(EXTRA_MESSAGE, message);
f.setArguments(bdl);
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
String message = getArguments().getString(EXTRA_MESSAGE);
View v = inflater.inflate(R.layout.myfragment_layout, container, false);
TextView messageTextView = (TextView)v.findViewById(R.id.TextView);
messageTextView.setText(message);
return v;
}
}
MyPageAdapter.java：
package com.example.loginandregistration;
import java.util.List;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class MyPageAdapter extends FragmentPagerAdapter {
private List<Fragment> fragments;
public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
@Override
public Fragment getItem(int position) {
return this.fragments.get(position);
}
@Override
public int getCount() {
return this.fragments.size();
}
}
PageViewActivity.java：
package com.example.loginandregistration;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
public class PageViewActivity extends FragmentActivity {
MyPageAdapter pageAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dashboard);
List<Fragment> fragments = getFragments();
pageAdapter = new MyPageAdapter(getSupportFragmentManager(), fragments);
ViewPager pager = (ViewPager)findViewById(R.id.viewpager);
pager.setAdapter(pageAdapter);
}
private List<Fragment> getFragments(){
List<Fragment> fList = new ArrayList<Fragment>();
fList.add(MyFragment.newInstance("Create Pic"));
fList.add(MyFragment.newInstance("Create Folder"));
fList.add(MyFragment.newInstance("Send Pic"));
return fList;
}
private class MyPageAdapter extends FragmentPagerAdapter {
private List<Fragment> fragments;
public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
@Override
public Fragment getItem(int position) {
return this.fragments.get(position);
}
@Override
public int getCount() {
return this.fragments.size();
}
}
}
TabsViewPagerFragmentActivity.java：
package com.example.loginandregistration;
import java.util.HashMap;
import java.util.List;
import java.util.Vector;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.widget.TabHost;
import android.widget.TabHost.TabContentFactory;
/**
* The <code>TabsViewPagerFragmentActivity</code> class implements the Fragment activity that maintains a TabHost using a ViewPager.
* @author mwho
*/
public class TabsViewPagerFragmentActivity extends FragmentActivity implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
private TabHost mTabHost;
private ViewPager mViewPager;
private HashMap<String, TabInfo> mapTabInfo = new HashMap<String, TabsViewPagerFragmentActivity.TabInfo>();
private MyPageAdapter mPagerAdapter;
/**
*
* @author mwho
* Maintains extrinsic info of a tab's construct
*/
private class TabInfo {
private String tag;
private Class<?> clss;
private Bundle args;
private Fragment fragment;
TabInfo(String tag, Class<?> clazz, Bundle args) {
this.tag = tag;
this.clss = clazz;
this.args = args;
}
}
/**
* A simple factory that returns dummy views to the Tabhost
* @author mwho
*/
class TabFactory implements TabContentFactory {
private final Context mContext;
/**
* @param context
*/
public TabFactory(Context context) {
mContext = context;
}
/** (non-Javadoc)
* @see android.widget.TabHost.TabContentFactory#createTabContent(java.lang.String)
*/
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
/** (non-Javadoc)
* @see android.support.v4.app.FragmentActivity#onCreate(android.os.Bundle)
*/
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Inflate the layout
setContentView(R.layout.dashboard);
// Initialise the TabHost
this.initialiseTabHost(savedInstanceState);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); //set the tab as per the saved state
}
// Intialise ViewPager
this.intialiseViewPager();
}
/** (non-Javadoc)
* @see android.support.v4.app.FragmentActivity#onSaveInstanceState(android.os.Bundle)
*/
protected void onSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost.getCurrentTabTag()); //save the tab selected
super.onSaveInstanceState(outState);
}
/**
* Initialise ViewPager
*/
private void intialiseViewPager() {
List<Fragment> fragments = new Vector<Fragment>();
fragments.add(Fragment.instantiate(this, CreatePic.class.getName()));
fragments.add(Fragment.instantiate(this, CreateFolder.class.getName()));
fragments.add(Fragment.instantiate(this, SendPic.class.getName()));
this.mPagerAdapter = new MyPageAdapter(super.getSupportFragmentManager(), fragments);
//
this.mViewPager = (ViewPager)super.findViewById(R.id.viewpager);
this.mViewPager.setAdapter(this.mPagerAdapter);
this.mViewPager.setOnPageChangeListener(this);
}
/**
* Initialise the Tab Host
*/
private void initialiseTabHost(Bundle args) {
mTabHost = (TabHost)findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab1").setIndicator("Tab 1"), ( tabInfo = new TabInfo("Tab1", CreatePic.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab2").setIndicator("Tab 2"), ( tabInfo = new TabInfo("Tab2", CreateFolder.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsViewPagerFragmentActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab3").setIndicator("Tab 3"), ( tabInfo = new TabInfo("Tab3", SendPic.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
// Default to first tab
//this.onTabChanged("Tab1");
//
mTabHost.setOnTabChangedListener(this);
}
/**
* Add Tab content to the Tabhost
* @param activity
* @param tabHost
* @param tabSpec
* @param clss
* @param args
*/
private static void AddTab(TabsViewPagerFragmentActivity activity, TabHost tabHost, TabHost.TabSpec tabSpec, TabInfo tabInfo) {
// Attach a Tab view factory to the spec
tabSpec.setContent(activity.new TabFactory(activity));
tabHost.addTab(tabSpec);
}
/** (non-Javadoc)
* @see android.widget.TabHost.OnTabChangeListener#onTabChanged(java.lang.String)
*/
public void onTabChanged(String tag) {
//TabInfo newTab = this.mapTabInfo.get(tag);
int pos = this.mTabHost.getCurrentTab();
this.mViewPager.setCurrentItem(pos);
}
/* (non-Javadoc)
* @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrolled(int, float, int)
*/
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
// TODO Auto-generated method stub
}
/* (non-Javadoc)
* @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageSelected(int)
*/
@Override
public void onPageSelected(int position) {
// TODO Auto-generated method stub
this.mTabHost.setCurrentTab(position);
}
/* (non-Javadoc)
* @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrollStateChanged(int)
*/
@Override
public void onPageScrollStateChanged(int state) {
// TODO Auto-generated method stub
}
}
仪表板活动.java：
package com.example.loginandregistration;
import java.util.HashMap;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import library.DatabaseHandler;
import library.UserFunctions;
public class DashboardActivity extends Activity {
UserFunctions userFunctions;
Button btnLogout;
DatabaseHandler dbHandler;
private HashMap<String, String> user;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
userFunctions = new UserFunctions();
if(userFunctions.isUserLoggedIn(getApplicationContext())){
// user already logged in show databoard
setContentView(R.layout.dashboard);
btnLogout = (Button) findViewById(R.id.btnLogout);
dbHandler = new DatabaseHandler(getApplicationContext());
user = dbHandler.getUserDetails();
TextView emailTextView = (TextView) findViewById(R.id.emailTextView);
emailTextView.setText(user.get("email"));
btnLogout.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
// TODO Auto-generated method stub
userFunctions.logoutUser(getApplicationContext());
Intent login = new Intent(getApplicationContext(), LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
// Closing dashboard screen
finish();
}
});
}else{
// user is not logged in show login screen
Intent login = new Intent(getApplicationContext(), LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
// Closing dashboard screen
finish();
}
}
}
Myfragmentlayout.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/TextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>