Android 中启动自己另一个程序的activity如何实现

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:<a href="http://lib.csdn.net/base/android" rel="external nofollow" class='replace_word' title="Android知识库" target='_blank' style='color:#df3434; font-weight:bold;'>Android</a>="http://schemas.android.com/apk/res/android"    package="net.devdiv.activity4"    android:versionCode="1"    android:versionName="1.0">   <application android:icon="@drawable/icon" android:label="@string/app_name">     <activity android:name=".activity4"          android:label="@string/app_name">       <intent-filter>         <action android:name="android.intent.action.MAIN" />         <category android:name="android.intent.category.LAUNCHER" />       </intent-filter>       <intent-filter>         <action android:name="devdiv.intent.action.activity4" />         <category android:name="android.intent.category.DEFAULT" />       </intent-filter>     </activity>   </application>   <uses-sdk android:minSdkVersion="7" /> </manifest>  

    Intent intent = new Intent("devdiv.intent.action.activity4");       startActivity(intent);