Question

enter image description here我是android的新手，现在我通过udacity.com教程引用了sun app。代码是相同的，但仍然没有显示选项设置，并且没有在操作栏上刷新
我该如何解决我的问题？
主要活动。主菜单的java代码

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new ForecastFragment())
                    .commit();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, 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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

和ForecastFragment.java用于刷新菜单

public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.forecastfragment, menu);
}

主菜单xml文件代码

  <menu 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"
      tools:context="com.example.android.sunshine.app.MainActivity" >
      <item android:id="@+id/action_settings"
     android:orderInCategory="100" />
    app:showAsAction="never"
    android:title="@string/action_settings"
   android:orderInCategory="100" /></menu>

刷新菜单位于forecastfragment.xml文件代码中，refrsh菜单是

<item android:id="@+id/action_refresh"
    app:showAsAction="never"
    android:title="@string/action_refresh"
    android:orderInCategory="100" />

清单文件是

<application android:allowBackup="true"    
             android:icon="@drawable/ic_launcher"      
             android:label="@string/app_name"       
             android:theme="@style/AppTheme" >       
    <activity android:name=".MainActivity"           
              android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

style.xml文件

 <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"> 
 <!-- Customize your theme here. -->   
<item name="android:icon">@drawable/ic_launcher</item>
</style>
<!--style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style-->
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

Answer 1

在片段的gaierror occurred err invoked gaierror occurred err invoked gaierror occurred err invoked gaierror occurred ...方法中写

onCreateView

并将此setHasOptionsMenu(true);添加到您的super.onCreateOptionsMenu(menu, inflater);

onCreateOptionsMenu

您可以在public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { super.onCreateOptionsMenu(menu, inflater); inflater.inflate(R.menu.forecastfragment, menu); }

中添加以下代码

activity_main.xml

这在您的<android.support.v7.widget.Toolbar android:id="@+id/toolBar" android:layout_width="match_parent" android:layout_height="wrap_content"></android.support.v7.widget.Toolbar>

中

MainActivity.java

您的完整Toolbar mToolbar = (Toolbar) findViewById(R.id.toolBar); setSupportActionBar(mToolbar);应如下所示

公共类MainActivity扩展了AppCompatActivity {

MainActivity

}

如果您想要显示刷新菜单，则需要将此代码放入片段@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar mToolbar = (Toolbar) findViewById(R.id.toolBar); setSupportActionBar(mToolbar); if (savedInstanceState == null) { getSupportFragmentManager().beginTransaction() .add(R.id.container, new PlaceholderFragment()) .commit(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, 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; } return super.onOptionsItemSelected(item); } public static class PlaceholderFragment extends Fragment { public PlaceholderFragment() { } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_main, container, false); //setHasOptionsMenu(true); return rootView; } public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { super.onCreateOptionsMenu(menu, inflater); inflater.inflate(R.menu.menu_main, menu); } }

你setHasOptionsMenu(true);就像这样

activity_main.xml

它应该有用......

Answer 2

在你的menu.xml中你必须设置app：showAsAction =＆＃34; always＆＃34;它会显示出来。

Answer 3

材料设计确实不支持ActionBar。因此，您无法看到ActionBar以及App图标。如果您想要ActionBar之类的功能，那么您可以使用类似以下代码的工具栏...

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

Answer 4

从ActionBarActivity类扩展baseClass。

这应该解决这个问题。

public class MainActivity extends ActionBarActivity{
}

android studio中没有显示操作栏选项

4 个答案: