该 <activity> 元素必须是的直接子元素 <application> 元件

Question

I just wanted to launch my application, but it always fails and gives me this error. Before, it would just install the .apk file, but now it just fails to start at all. I just began and was following the Android Developing tutorial.

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.myfirstapp"
        android:versionCode="1"
        android:versionName="1.0" >

        <uses-sdk
            android:minSdkVersion="8"
            android:targetSdkVersion="17" />

        <application
            android:allowBackup="true"
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name"
            android:theme="@style/AppTheme" >
            <activity
                android:name="com.example.myfirstapp.MainActivity"
                android:label="@string/app_name" >
                <activity
                    android:name="com.example.myfirstapp.DisplayMessageActivity"
                    android:label="@string/title_activity_display_message"
                    android:parentActivityName="com.example.myfirstapp.MainActivity" >
                    <meta-data
                        android:name="android.support.PARENT_ACTIVITY"
                        android:value="com.example.myfirstapp.MainActivity" >
                        <intent-filter>
                            <action android:name="android.intent.action.MAIN" />
                            <category android:name="android.intent.category.LAUNCHER" />
                        </intent-filter>
                    </meta-data>
                </activity>
            </activity>
        </application>

    </manifest>

Answer 1

您的清单中不能包含嵌套的活动标签，请解决此问题，它应该可以工作。

Answer 2

You don't nest Activities in other Activities . This is how it should look like:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myfirstapp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.myfirstapp.MainActivity"
            android:label="@string/app_name" >
        </activity>
        <activity
            android:name="com.example.myfirstapp.DisplayMessageActivity"
            android:label="@string/title_activity_display_message"
            android:parentActivityName="com.example.myfirstapp.MainActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.example.myfirstapp.MainActivity" >
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />

                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </meta-data>
        </activity>
    </application>

</manifest>

Do read the Android docs for the AndroidManifest.xml file

Answer 3

YES - for example:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example" android:versionCode="1" android:versionName="1.0">
  <uses-sdk android:minSdkVersion="3" />

  <uses-permission android:name="android.permission.SET_WALLPAPER"></uses-permission>
  <uses-permission android:name="android.permission.VIBRATE"></uses-permission>
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
  <uses-permission android:name="android.permission.CAMERA" />
  <uses-permission android:name="android.permission.WAKE_LOCK" />

  <uses-feature android:name="android.hardware.camera" /> 

  <application 
      android:icon="@drawable/icon" android:label="@string/app_name">

    <!-- Boot window -->
    <activity 
        android:name=".ServicesDemo" android:label="@string/app_name">        
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />           
        <category android:name="android.intent.category.HOME" />     
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>

    </activity>

    <!-- Second window -->
    <activity android:name=".MainActivity" android:label="@string/app_name" 
        android:parentActivityName=".ServicesDemo" />       
    <!-- Second window -->
    <activity android:name=".MyWall" android:label="@string/app_name" 
        android:parentActivityName=".ServicesDemo" />    
    <!-- Second window -->
    <activity android:name=".MyRotations" android:label="@string/app_name" 
        android:parentActivityName=".ServicesDemo" />
    <!-- Second window -->
    <activity android:name=".MySetting" android:label="@string/app_name" 
        android:parentActivityName=".ServicesDemo" />

    <receiver 
        android:enabled="true"
        android:name=".IntentReceiver"
        android:permission="android.permission.RECEIVE_BOOT_COMPLETED"
        >
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <action android:name="android.intent.action.USER_PRESENT" />            
            <action android:name="android.intent.action.HEADSET_PLUG" />
            <action android:name="android.intent.action.SCREEN_ON" />
            <action android:name="android.intent.action.SCREEN_OFF" />            
            <category android:name="android.intent.category.DEFAULT" />            
        </intent-filter>
    </receiver>  

    <service android:enabled="true" android:name=".MyService" />
    <service android:enabled="true" android:name=".MyNewpic" />

  </application>

</manifest>