在Manifest.xml中更改活动名称非常简单。

< application> 
 android：allowBackup =   true 
 android：icon =   @ drawable / ic_launcher 
 android：label =    @ string / app_name 
 android：theme =   @ style / AppTheme> 
< activity> 
 android：name =   .yourActivityName  //  使用您的活动类名称更改.MainActivity。 
 android：noHistory =   true 
 android：screenOrientation =  肖像> 
< intent-filter> 
< action android：name =   android.intent.action.MAIN xmlns： android =  ＃unknown /> 

< category android：name =   android.intent.category.LAUNCHER xmlns：android =  ＃unknown /> 
< / intent-filter> 
< / activity> 
< activity> 
 android：name =  。MainActivity  //  稍后调用MainActivity  
 android：screenOrientation =   portrait> 
< / activity> 
< / application> 

hello every one good morning .
in my android app multiple activites define when ever app is start so main activity is launch but i don't want to launch main activities i want to launch different other activities when ever app is launche ?
so how it is done
can u help me any one ???
thanks...

It's as simple to change your activity name in your Manifest.xml.

<application>
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity>
            android:name=".yourActivityName"  //Change .MainActivity with your Activity Class name.
            android:noHistory="true"
            android:screenOrientation="portrait" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" xmlns:android="#unknown" />

                <category android:name="android.intent.category.LAUNCHER" xmlns:android="#unknown" />
            </intent-filter>
        </activity>
        <activity>
            android:name=".MainActivity"  // call MainActivity later
            android:screenOrientation="portrait" >
        </activity>
    </application>