Why doesn’t the application icon appear in the title bar when creating an application with Android Studio?

Question

Before I created an Android application with eclipse, it can display the application icon on the left side of the title bar, see image aa.png.

Now I am creating an Android application with Android Studio, I will add the android:icon="@mipmap/ic_launcher" to the manifest.xml file, but the application icon does not appear, see image bb.png, why?

BTW, the icon may appear if you replace compile 'com.android.support:appcompat-v7:22.1.1' with compile 'com.android.support:appcompat-v7:18.0.0' , why? are there any errors with com.android.support:appcompat-v7:22.1.1?

aa.png

bb.png

 <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.cuiwei.myapplication" > <application android:allowBackup="true" android:icon="@mipmap/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> </manifest> <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:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"> <TextView android:text="@string/hello_world" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </RelativeLayout> apply plugin: 'com.android.application' android { compileSdkVersion 22 buildToolsVersion "22.0.1" defaultConfig { applicationId "com.example.cuiwei.myapplication" minSdkVersion 9 targetSdkVersion 22 versionCode 1 versionName "1.0" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) compile 'com.android.support:appcompat-v7:22.1.1' } <resources> <!-- Base application theme. --> <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"> <!-- Customize your theme here. --> </style> </resources> 

Answer 1

 <activity android:name=".MainActivity" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> 

If it does not work, you should call getSupportActionBar().setIcon(Drawable/int) or getSupportActionBar().setLogo(Drawable/int) in Activity .

Answer 2

Using Android 5.0 styles (e.g. AppCompat), the application icon does not appear in the action bar.

You can see the application icon if you use the Android Holo theme. To do this, change android: theme to "android: Theme.Holo" or "android: Theme.Holo.Light".

Hope this helps.