菜单未在应用中显示

出于某种原因,我的操作菜单在我的Android Studio应用程序中消失了。 我正在按照教程学习如何创建一个Android应用程序,但我最终遇到了这个问题。

我正在使用atm的教程: http : //www.raywenderlich.com/56109/make-first-android-app-part-2

这是我的main.xml的样子:

     

menu_main.xml:

      

我在这段代码中做错了什么? 我没有得到任何错误。 我几乎从教程中复制粘贴了这个。

我不认为它是我的java代码,但仍然在这里,有人认为问题在于该代码。 MainActivity.java:

 package android.stefan.testappnieuw; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.ListView; import android.widget.TextView; import java.util.ArrayList; public class MainActivity extends Activity implements View.OnClickListener, AdapterView.OnItemClickListener { TextView mainTextView; Button mainButton; EditText mainEditText; ListView mainListView; ArrayAdapter mArrayAdapter; ArrayList mNameList = new ArrayList(); android.widget.ShareActionProvider mShareActionProvider; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 1. Access the TextView defined in layout XML // and then set its text mainTextView = (TextView) findViewById(R.id.main_textview); mainTextView.setText("Set in Java!"); // 2. Access the Button defined in layout XML // and listen for it here mainButton = (Button) findViewById(R.id.main_button); mainButton.setOnClickListener(this); // 3. Access the EditText defined in layout XML mainEditText = (EditText) findViewById(R.id.main_edittext); // 4. Access the ListView mainListView = (ListView) findViewById(R.id.main_listview); // 5. Set this activity to react to list items being pressed mainListView.setOnItemClickListener(this); // Create an ArrayAdapter for the ListView mArrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, mNameList); // Set the ListView to use the ArrayAdapter mainListView.setAdapter(mArrayAdapter); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu. // Adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); // Access the Share Item defined in menu XML MenuItem shareItem = menu.findItem(R.id.menu_item_share); // Access the object responsible for // putting together the sharing submenu if (shareItem != null) { mShareActionProvider = (android.widget.ShareActionProvider)shareItem.getActionProvider(); } // Create an Intent to share your content setShareIntent(); return true; } private void setShareIntent() { if (mShareActionProvider != null) { // create an Intent with the contents of the TextView Intent shareIntent = new Intent(Intent.ACTION_SEND); shareIntent.setType("text/plain"); shareIntent.putExtra(Intent.EXTRA_SUBJECT, "Android Development"); shareIntent.putExtra(Intent.EXTRA_TEXT, mainTextView.getText()); // Make sure the provider knows // it should work with that Intent mShareActionProvider.setShareIntent(shareIntent); } } @Override public void onClick(View v) { // Take what was typed into the EditText // and use in TextView mainTextView.setText(mainEditText.getText().toString() + " Hallo"); // Also add that value to the list shown in the ListView mNameList.add(mainEditText.getText().toString()); mArrayAdapter.notifyDataSetChanged(); // 6. The text you'd like to share has changed, // and you need to update setShareIntent(); } @Override public void onItemClick(AdapterView parent, View view, int position, long id) { // Log the item's position and contents // to the console in Debug Log.d("omg android", position + ": " + mNameList.get(position)); } } 

我真的不知道什么是错的我是java / android的新手,并且出于某种原因菜单栏出现在教程中但不适合我。

感谢阅读/帮助!

   

ifRoom表示是否有空间可供展示。 始终让它始终显示。

转到您的清单文件并添加或更改此应用程序属性,如果不可用则查找类似的内容,还有更多使用操作栏

 android:theme="@style/ThemeOverlay.AppCompat.ActionBar" > 
  1. select_patient xml包含如下菜单: –

       
  2. 在您的活动中扩展“ActionBarActivity”。

  3. 确保您在活动中也添加了以下代码行

     @Override public boolean onCreateOptionsMenu(Menu menu) { SharedMenu.onCreateOptionMenu(menu, this, R.menu.select_patient); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { if (SharedMenu.onOptionsItemSelected(item, this) == false) { // handle local menu items here or leave blank } return super.onOptionsItemSelected(item); }