#创建第二个activity
* Newly created activity, must be configured in the manifest file, otherwise the system can not be found, the display will be directly error
<activity android:name= "Com.itheima.createactivity.SecondActivity" ></activity>
* As long as the following code, then is the portal activity, will generate a shortcut icon
<intent-filter>
<action android:name= "Android.intent.action.MAIN"/>
<category android:name= "Android.intent.category.LAUNCHER"/>
</intent-filter>
* If the activity contains a package with the same name as the application package, you can omit the
1. Create class classes to inherit activity
2. Create the layout file as the activity display content
3. Registering activity in the manifest file
#Activity的跳转
# # #隐式跳转
* One activity if you need an implicit jump, you must add the following child nodes in the manifest file
<intent-filter >
<action android:name= "Com.itheima.sa"/>
<category android:name= "Android.intent.category.DEFAULT"/>
</intent-filter>
* The name of the action node is defined by itself, and when defined, the value of this name becomes the activity action, and when the activity is implicitly started, the action set in the intent must match "com.itheima.sa" exactly.
# # #应用场景
* Display: Activate activity in the same application
* Implicit intent: Activate activity in different applications
* Re-start efficiency, implicit is much lower than the explicit
* If there is more than one activity in the system that matches the action you intend to set, a dialog box will pop up when you start the activity with all the matching activity
android--the difference between explicit and implicit jumps
