导航抽屉中的ViewPager-请给出一些建议

Question

所以总的想法是在第一个(主页)有滑动图库，我做到了，但当我从导航菜单中选择选项时，我有寻呼机布局开关是我的导航抽屉布局，它的空白cuz只包含android.support.v4.view.ViewPager

CONTENT_MAIN.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/pager"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.marcj.justtest.drawer"
>
</android.support.v4.view.ViewPager>

但现在我想去我的导航抽屉，在那里选择一个选项，并拥有OTHER刷图库。。但我不知道该怎么做，因为当我选择选项时，例如SOLD我的布局是空白的。

在此处输入图像描述

drawer.java文件：

package com.example.marcj.justtest;
import java.math.BigDecimal;
public class drawer extends AppCompatActivity implements         
NavigationView.OnNavigationItemSelectedListener {
ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_drawer);
viewPager = (ViewPager) findViewById(R.id.pager);
PageAdapter padapter = new PageAdapter(getSupportFragmentManager());
viewPager.setAdapter(padapter);


Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open,             
R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) 
findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
View headerView = navigationView.getHeaderView(0);
String username = getIntent().getStringExtra("username");
TextView text2 = (TextView) headerView.findViewById(R.id.TVusername);
text2.setText(username);

}




@Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.navigation, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
} else if (id == R.id.action_contact) {
Toast.makeText(this, "Contact Form", Toast.LENGTH_SHORT).show();

Intent i = new Intent(drawer.this, AcContact.class);
startActivity(i);
contact contactForm = new contact();
FragmentManager manager = getSupportFragmentManager();
manager.beginTransaction().replace(R.id.pager,
contactForm, contactForm.getTag()).commit();
}   else if (id == R.id.nav_clicked) {
}
return super.onOptionsItemSelected(item);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_homepage) {
Intent i= new Intent (drawer.this, drawer.class );
startActivity(i);
} else if (id == R.id.nav_clicked) {
Toast.makeText(this, "Clicked Items", Toast.LENGTH_SHORT).show();
clicked clickedItems = new clicked();
FragmentManager manager = getSupportFragmentManager();
manager.beginTransaction().replace(R.id.pager,
clickedItems, clickedItems.getTag()).commit();

} else if (id == R.id.nav_won) {
Toast.makeText(this, "Won Items", Toast.LENGTH_SHORT).show();
won wonItems = new won();
FragmentManager manager = getSupportFragmentManager();
manager.beginTransaction().replace(R.id.pager,
wonItems, wonItems.getTag()).commit();
} else if (id == R.id.nav_selling) {
Toast.makeText(this, "Item that you Selling", 
Toast.LENGTH_SHORT).show();
selling sellingItems = new selling();
FragmentManager manager = getSupportFragmentManager();
manager.beginTransaction().replace(R.id.pager,
sellingItems, sellingItems.getTag()).commit();
} else if (id == R.id.nav_sold) {
Toast.makeText(this, "Sold Items", Toast.LENGTH_SHORT).show();
sold soldItems = new sold();
FragmentManager manager = getSupportFragmentManager();
manager.beginTransaction().replace(R.id.pager,
soldItems, soldItems.getTag()).commit();
} else if (id == R.id.nav_topup) {
Toast.makeText(this, "Top-Up Clicks", Toast.LENGTH_SHORT).show();
topup topupItems = new topup();
FragmentManager manager = getSupportFragmentManager();
manager.beginTransaction().replace(R.id.pager,
topupItems, topupItems.getTag()).commit();
} else if (id == R.id.nav_share) {


}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}

PageAdapter.java

package com.example.marcj.justtest;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

public class PageAdapter extends FragmentPagerAdapter {
public PageAdapter (FragmentManager fm){
super(fm);
}
public Fragment getItem (int arg0){
switch (arg0){
case 0:
return new FragmentOne();
case 1:
return new FragmentTwo();
case 2:
return new FragmentThree();

default:
break;
}
return null;
}

public int getCount(){
return 3;
}
}

Activity_drawer.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">
<include
layout="@layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_main"
app:menu="@menu/activity_drawer_menu" />
</android.support.v4.widget.DrawerLayout>

app_bar_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".drawer">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme" />
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_main" />

</android.support.design.widget.CoordinatorLayout>

activity_drawer.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">
<include
layout="@layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_main"
app:menu="@menu/activity_drawer_menu" />
</android.support.v4.widget.DrawerLayout>

Answer 1

activity_drawer文件：

android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">
<include
layout="@layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_main"
app:menu="@menu/activity_drawer_menu" />

content_main

android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/pager"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.marcj.justtest.drawer"
>