Android Studio 中未顯示操作欄

Question

我是第一次使用 Android Studio，在運行應用程序時無法顯示ActionBar 。 這是我到目前為止所擁有的：

我的活動MainActivity.java

package xeniasis.mymarket;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.support.v7.app.ActionBar;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);

        return super.onCreateOptionsMenu(menu);
    }
}

它的布局activity_main.xml （沒有）

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="xeniasis.mymarket.MainActivity"></RelativeLayout>

和帶有一項的菜單activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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="xeniasis.mymarket.MainActivity">
    <item
        android:id="@+id/action_update"
        android:icon="@drawable/ic_action_update"
        android:showAsAction="ifRoom"
        android:title="@string/update_app" />
</menu>

我需要其他東西才能顯示ActionBar嗎？

編輯

這是應用程序主題

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

Answer 1

按照 Material Design 將AppCompatActivity與ToolBar一起使用。

public class MyActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        // Find the toolbar view inside the activity layout
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        // Sets the Toolbar to act as the ActionBar for this Activity window.
        // Make sure the toolbar exists in the activity and is not null
        setSupportActionBar(toolbar);
    }

    // Menu icons are inflated just as they were with actionbar
    @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;
    }
}

activity_my.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.Toolbar
      android:id="@+id/toolbar"
      android:minHeight="?attr/actionBarSize"  
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      app:titleTextColor="@android:color/white"
      android:background="?attr/colorPrimary">
    </android.support.v7.widget.Toolbar>

    <!-- Layout for content is here. This can be a RelativeLayout  -->

</LinearLayout>

在Style.xml添加它。

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
  <!-- Customize your theme here. -->
  <item name="colorPrimary">@color/colorPrimary</item>
  <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
  <item name="colorAccent">@color/colorAccent</item>
</style>

<style name="ToolbarTheme" parent="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
  <!-- This would set the toolbar's background color -->
  <item name="android:background">@color/colorPrimary</item>
  <!-- android:textColorPrimary is the color of the title text in the Toolbar  -->
  <item name="android:textColorPrimary">@android:color/holo_blue_light</item>
  <!-- android:actionMenuTextColor is the color of the text of action (menu) items  -->
  <item name="actionMenuTextColor">@android:color/holo_green_light</item>
  <!-- Enable these below if you want clicking icons to trigger a ripple effect -->
  <!-- 
  <item name="selectableItemBackground">?android:selectableItemBackground</item>
  <item name="selectableItemBackgroundBorderless">?android:selectableItemBackground</item> 
  -->
</style>

<!-- This configures the styles for the title within the Toolbar  -->
<style name="Toolbar.TitleText" parent="TextAppearance.Widget.AppCompat.Toolbar.Title">
    <item name="android:textSize">21sp</item>
    <item name="android:textStyle">italic</item>
</style>

菜單文件

<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/miCompose"
        android:icon="@drawable/ic_compose"
        app:showAsAction="ifRoom"
        android:title="Compose">
    </item>
    <item
        android:id="@+id/miProfile"
        android:icon="@drawable/ic_profile"
        app:showAsAction="ifRoom|withText"
        android:title="Profile">
    </item>
</menu>

Answer 2

你必須叫你 actionBar 幾乎類似於你如何膨脹視圖並記住使用工具欄

Toolbar toolbar = (Toolbar)this.findViewById(R.id.action_bar);
      if(toolbar!=null){

      }
      //getSupportActionBar().setHomeButtonEnabled(true);
      getSupportActionBar().setDisplayShowHomeEnabled(true);
      getSupportActionBar().setDisplayUseLogoEnabled(true);

      getSupportActionBar().setLogo(R.drawable.ic__actionbar);

      // Set up the action bar.
      final ActionBar actionBar = getSupportActionBar();
      if (showTabs) actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

      // Create the adapter that will return a fragment for each of the three
      // primary sections of the activity.

Answer 3

在設計視圖中，單擊眼睛圖標（視圖選項）並選擇“顯示布局裝飾”