当用户点击导航抽屉中的任何项目时，我正在尝试显示不同的片段。我无法显示片段。我没有收到任何错误消息。它只是没有显示片段。
布局：
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawerlayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- The main content view -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/main_content"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="@+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
<android.support.v7.widget.RecyclerView
android:id="@+id/notes_list"
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
<!-- The navigation drawer -->
<ListView android:id="@+id/navigationitems"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:background="@android:color/darker_gray"
android:dividerHeight="0dp"
/>
</android.support.v4.widget.DrawerLayout>
MainActivity:
package com.example.note.pankajpc.note;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.app.SearchManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.SearchView;
import android.support.v7.widget.Toolbar;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.FrameLayout;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import io.realm.Case;
import io.realm.Realm;
import io.realm.RealmChangeListener;
import io.realm.RealmResults;
import io.realm.Sort;
public class MainActivity extends AppCompatActivity {
private ListView mNavigationItem;
private DrawerLayout mDrawerLayout;
private FrameLayout mMainContent;
Intent intent;
String [] mNavigationItemArray;
List <DrawerItem> mDrawerItem = new ArrayList();
private ActionBarDrawerToggle mDrawerToggle;
private RecyclerView mRecyclerView;
private static NoteAdapter mNoteAdapter;
private static Realm mRealm;
private static Context context1;
private RealmResults<NoteModel> mResults;
SearchView mSearchView;
String mSearchString=null;
private ContextMenu contextMenu;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
setSupportActionBar(myToolbar);
Realm.init(this);
context1 = this;
// initAlarm();
mRealm = Realm.getDefaultInstance();
//initialize relam database
initUi();
initDrawerItem();
mRecyclerView = (RecyclerView)findViewById(R.id.notes_list);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));
mNoteAdapter = new NoteAdapter(this,mResults,mRealm);
mRecyclerView.setAdapter(mNoteAdapter);
mNavigationItemArray = getResources().getStringArray(R.array.navigation_list);
mNavigationItem = (ListView)findViewById(R.id.navigationitems);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerlayout);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_navigation);
mDrawerToggle = new ActionBarDrawerToggle(this,mDrawerLayout,R.string.app_name,R.string.app_name){
};
mDrawerLayout.addDrawerListener(mDrawerToggle);
//setting custom adapter on Navigation Drawer
mNavigationItem.setAdapter(new CustomDrawerAdapter(this,R.layout.custom_navigation_listview_row,mDrawerItem));
//setting onClick Listener on Navigation Drawer
mNavigationItem.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Fragment fragment = null;
mDrawerLayout.closeDrawers();
switch (mDrawerItem.get(i).getItemName()){
case "Add a Note":
intent = new Intent(MainActivity.this,AddNote.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);
break;
case "Settings":
Toast.makeText(MainActivity.this,"test1",Toast.LENGTH_SHORT).show();
Fragment fragment1 = new TestFragment();
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.main_content, fragment1);
ft.commit();
break;
}
}
});
}
private void initAlarm() {
Intent i = new Intent(this,AlarmReceiver.class);
PendingIntent alarmIntent = PendingIntent.getBroadcast(this, 0, i, 0);
AlarmManager am = (AlarmManager)this.getSystemService(ALARM_SERVICE);
am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,200,200,alarmIntent);
}
private void initDrawerItem() {
mDrawerItem.add(new DrawerItem("Notes",R.drawable.ic_notes));
mDrawerItem.add(new DrawerItem("Add a Note",R.drawable.ic_add));
mDrawerItem.add(new DrawerItem("Search",R.drawable.ic_search));
mDrawerItem.add(new DrawerItem("Trash",R.drawable.ic_trash));
mDrawerItem.add(new DrawerItem("Settings",R.drawable.ic_settings));
}
private void initUi() {
mResults = mRealm.where(NoteModel.class).findAllSortedAsync("mNoteDateTime");
}
protected void onStart() {
super.onStart();
this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
mResults.addChangeListener(new RealmChangeListener<RealmResults<NoteModel>>() {
@Override
public void onChange(RealmResults<NoteModel> element) {
mNoteAdapter.update(mResults);
}
});
}
@Override
//This override displays the items when action bar up button click
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
//handling the menu clicks on menu.xml
switch (id){
case R.id.actionAdd:
startActivity((new Intent(context1,AddNote.class)).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP));
break;
case R.id.dateCreated:
mResults = mRealm.where(NoteModel.class).findAllSorted("mNoteDateTime");
mNoteAdapter.update(mResults);
break;
case R.id.alphabetically:
mResults = mRealm.where(NoteModel.class).findAllSorted("mNoteTitle");
mNoteAdapter.update(mResults);
break;
case R.id.priority:
mResults = mRealm.where(NoteModel.class).findAllSorted("mNotePriority", Sort.DESCENDING);
mNoteAdapter.update(mResults);
break;
}
return true;
}
@Override
public boolean onCreateOptionsMenu(final Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
mSearchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
mSearchView.setSearchableInfo(
searchManager.getSearchableInfo(getComponentName()));
mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
String query = newText.toLowerCase();
mResults = mRealm.where(NoteModel.class).contains("mNoteTitle", query, Case.INSENSITIVE).findAllSorted("mNoteDateTime");
mNoteAdapter.update(mResults);
return false;
}
});
return true;
}
@Override
protected void onStop() {
super.onStop();
resetSearchView();
}
@Override
public void onBackPressed() {
super.onBackPressed();
resetSearchView();
}
private void resetSearchView() {
mSearchView.clearFocus();
mSearchView.setQuery("", false);
mSearchView.setFocusable(false);
mSearchView.onActionViewCollapsed();
}
}
片段：
package com.example.note.pankajpc.note;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* Created by Pankaj PC on 01-08-2017.
*/
public class TestFragment extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.add_note,container,false);
}
}
答案 0 :(得分：1)
你不能使用Linearlayout存储你的片段，它需要是你需要添加片段的Framelayout
这就是我总是设置导航抽屉的方法：
<?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">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize" />
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/appbar_layout" />
</RelativeLayout>
<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_main_drawer" />
</android.support.v4.widget.DrawerLayout>