Java 终身无法解析GetSupportActionBar()。setDisplayHomeAsUpEnabled可能会产生NullPointerException
我知道这已经讨论了很多,但我已经尝试了一切,将getSupportActionBar更改为getActionBar,将布局更改为片段活动,操作栏活动,将布局更改为工具栏。似乎没有什么能消除这一警告。谢谢你的帮助 哦,如果对main_menu.xml和menu_main.xml有混淆,那是因为我有一个溢出菜单,我正试图将它切换到滑动抽屉菜单 MainActivity.javaJava 终身无法解析GetSupportActionBar()。setDisplayHomeAsUpEnabled可能会产生NullPointerException,java,android,android-studio,slidingmenu,slidingdrawer,Java,Android,Android Studio,Slidingmenu,Slidingdrawer,我知道这已经讨论了很多,但我已经尝试了一切,将getSupportActionBar更改为getActionBar,将布局更改为片段活动,操作栏活动,将布局更改为工具栏。似乎没有什么能消除这一警告。谢谢你的帮助 哦,如果对main_menu.xml和menu_main.xml有混淆,那是因为我有一个溢出菜单,我正试图将它切换到滑动抽屉菜单 MainActivity.java package me.paxana.alerta; import android.app.Activity; impor
package me.paxana.alerta;
import android.app.Activity;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
import android.app.Fragment;
import android.content.Intent;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Toolbar;
import com.parse.ParseUser;
import java.util.ArrayList;
import java.util.List;
import butterknife.Bind;
import butterknife.ButterKnife;
import me.paxana.alerta.adapter.SlidingMenuAdapter;
import me.paxana.alerta.fragment.Fragment1;
import me.paxana.alerta.fragment.Fragment2;
import me.paxana.alerta.fragment.Fragment3;
import me.paxana.alerta.model.ItemSlideMenu;
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
private List<ItemSlideMenu> listSliding;
private SlidingMenuAdapter adapter;
private ListView listViewSliding;
private DrawerLayout drawerLayout;
private android.support.v7.app.ActionBarDrawerToggle actionBarDrawerToggle;
private Toolbar mToolbar;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
ParseUser currentUser = ParseUser.getCurrentUser();
if (currentUser == null) {
navigateToLogin();
}
else {
Log.i(TAG, currentUser.getUsername());
}
listViewSliding = (ListView)findViewById(R.id.lv_sliding_menu);
drawerLayout = (DrawerLayout)findViewById(R.id.drawer_layout);
listSliding = new ArrayList<>();
//add item for sliding list
listSliding. add(new ItemSlideMenu(R.drawable.ic_action_settings, "Settings"));
listSliding.add(new ItemSlideMenu(R.drawable.ic_action_about, "About"));
listSliding.add(new ItemSlideMenu(R.mipmap.ic_launcher, "Android"));
adapter = new SlidingMenuAdapter(this, listSliding);
listViewSliding.setAdapter(adapter);
//display icon to open/close slider
mToolbar = (Toolbar) findViewById(R.id.toolbar);
if (mToolbar != null)
{
setActionBar(mToolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setElevation(0); // or other
}
//set title
setTitle(listSliding.get(0).getTitle());
//item selected
listViewSliding.setItemChecked(0, true);
//close menu
drawerLayout.closeDrawer(listViewSliding);
//handle on item click
listViewSliding.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//set title
setTitle(listSliding.get(position).getTitle());
//item selected
listViewSliding.setItemChecked(position, true);
//close menu
drawerLayout.closeDrawer(listViewSliding);
}
});
actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.drawer_opened, R.string.drawer_closed) {
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
invalidateOptionsMenu();
}
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
invalidateOptionsMenu();
}
};
drawerLayout.setDrawerListener(actionBarDrawerToggle);
}
private void navigateToLogin() {
Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(actionBarDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
int itemId = item.getItemId();
if (itemId == R.id.action_logout) {
ParseUser.logOut();
navigateToLogin();
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
actionBarDrawerToggle.syncState();
}
//create method replace fragment
private void replaceFragment(int pos) {
android.support.v4.app.Fragment fragment = null;
switch (pos) {
case 0:
fragment = new Fragment1();
break;
case 1:
fragment = new Fragment2();
break;
case 2:
fragment = new Fragment3();
break;
default:
fragment = new Fragment1();
break;
}
if(null != fragment) {
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_content, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
}
}
package me.paxana.alerta;
导入android.app.Activity;
导入android.support.v4.app.FragmentActivity;
导入android.support.v4.app.FragmentTransaction;
导入android.support.v4.app.FragmentManager;
导入android.support.v7.app.ActionBar;
导入android.support.v7.app.ActionBarDrawerToggle;
导入android.app.Fragment;
导入android.content.Intent;
导入android.support.v4.widget.DrawerLayout;
导入android.support.v7.app.ActionBarActivity;
导入android.support.v7.app.AppActivity;
导入android.os.Bundle;
导入android.util.Log;
导入android.view.Menu;
导入android.view.MenuItem;
导入android.view.MenuInflater;
导入android.view.view;
导入android.widget.AdapterView;
导入android.widget.Button;
导入android.widget.ListView;
导入android.widget.RelativeLayout;
导入android.widget.Toolbar;
导入com.parse.ParseUser;
导入java.util.ArrayList;
导入java.util.List;
进口毛刀。装订;
进口毛刀,毛刀;
导入me.paxana.alerta.adapter.SlidingMenuAdapter;
导入me.paxana.alerta.fragment.Fragment1;
导入me.paxana.alerta.fragment.Fragment2;
导入me.paxana.alerta.fragment.Fragment3;
导入me.paxana.alerta.model.ItemSlideMenu;
公共类MainActivity扩展了AppCompatActivity{
公共静态最终字符串标记=MainActivity.class.getSimpleName();
私人名单;
专用滑动菜单适配器;
私有列表视图列表视图;
私人抽屉布局;
私有android.support.v7.app.ActionBarDrawerToggle操作BarDrawerToggle;
私有工具栏mToolbar;
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
把(这个)绑起来;
ParseUser currentUser=ParseUser.getCurrentUser();
if(currentUser==null){
导航登录();
}
否则{
Log.i(标记,currentUser.getUsername());
}
ListView滑动=(ListView)findViewById(R.id.lv\u滑动菜单);
抽屉布局=(抽屉布局)findViewById(R.id.抽屉布局);
listSliding=newarraylist();
//为滑动列表添加项目
添加(新项目slidemenu(R.drawable.ic_action_设置,“设置”);
添加(新项目slidemenu(R.drawable.ic_action_about,“about”);
添加(新的ItemSlideMenu(R.mipmap.ic_启动器,“Android”);
适配器=新滑动菜单适配器(此,列表滑动);
ListViewSlidering.setAdapter(适配器);
//显示打开/关闭滑块的图标
mToolbar=(工具栏)findviewbyd(R.id.Toolbar);
if(mToolbar!=null)
{
setActionBar(mToolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setElevation(0);//或其他
}
//定名
setTitle(listSliding.get(0.getTitle());
//选定项目
listViewSliding.setItemChecked(0,true);
//关闭菜单
抽屉布局。关闭抽屉(ListView滑动);
//单击项目时的句柄
listViewSliding.setOnItemClickListener(新的AdapterView.OnItemClickListener(){
@凌驾
public void onItemClick(AdapterView父对象、视图、整型位置、长id){
//定名
setTitle(listSliding.get(position.getTitle());
//选定项目
ListViewSlideing.setItemChecked(位置,true);
//关闭菜单
抽屉布局。关闭抽屉(ListView滑动);
}
});
actionBarDrawerToggle=新actionBarDrawerToggle(此,抽屉布局,R.string.drawer\u打开,R.string.drawer\u关闭){
@凌驾
打开图纸上的公共空白(视图抽屉视图){
super.onDrawerOpened(抽屉视图);
无效操作菜单();
}
@凌驾
图纸上的公共空白已关闭(视图抽屉视图){
super.onDrawerClosed(抽屉视图);
无效操作菜单();
}
};
抽屉布局。setDrawerListener(actionBarDrawerToggle);
}
私有void navigateToLogin(){
Intent Intent=新Intent(这是LoginActivity.class);
intent.addFlags(intent.FLAG\u活动\u新任务);
intent.addFlags(intent.FLAG\u活动\u清除\u任务);
星触觉(意向);
}
@凌驾
公共布尔onCreateOptions菜单(菜单){
MenuInflater充气机=getMenuInflater();
充气机。充气(右菜单。主菜单,菜单);
返回true;
}
@凌驾
公共布尔值onOptionsItemSelected(菜单项项){
如果(actionBarDrawerToggle.onOptionsItemSelected(项目)){
返回true;
}
int itemId=item.getItemId();
if(itemId==R.id.action\u注销){
ParseUser.logOut();
导航登录();
}
返回super.onOptionsItemSelected(项目);
}
@凌驾
后期创建时受保护的空(捆绑包savedInstanceState){
super.onPostCreate(savedInstanceState);
actionBarDrawerToggle.syncState();
}
//创建方法替换片段
私有void replaceFragment(内部位置){
android.support.v4.app.Fragment Fragment=null;
开关(pos){
案例0:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.app.DrawerLayout 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:id="@+id/drawer_layout"
tools:context="me.paxana.alerta.MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/main_content">
</RelativeLayout>
<ListView
android:layout_width="200dp"
android:layout_height="match_parent"
android:id="@+id/lv_sliding_menu"
android:background="#FFFFFF"
android:choiceMode="singleChoice"
android:layout_gravity="start" />
</android.support.v4.app.DrawerLayout>
setActionBar(mToolbar);
getSupportActionBar().foo;