[Android] displays the intention to activate another activity

You can use the jump method similar to Java Web to realize the interface transformation

The display intention is to specify the specific information of the open component, package name, component name and component class

Create a new class twoactivity, inherit the activity class and override the oncreate() method. This method is called automatically when the interface is opened. Most initialization operations are carried out in this function, such as calling the interface and obtaining controls

Activity is an important component of the system. If the system wants to find this activity, it must be configured in the manifest file

Add a new < activity / > node,

Setting Name: Android: name = "package name. Class name"

Set the name of the intention filter < intent Filter > action as android.intent.action.main; When the name of category is android.intent.category.launcher, a shortcut icon will be created

Set icon Android: icon = ""

Set title Android: label = ""

Some of the Android system is actually an application, creating different icons to enter different interfaces.

Click the button in the first activity to jump over

Get the intent object and get it through new

Call the setclassname (packagecontext, classname) method of the intent object to set the class name. Parameters: context. Class name of string type. The full name includes the package name

Call the startactivity (intent) method of the activity object to open an activity. Parameter: intent object

The above method is a little troublesome, and Google provides a slightly convenient way

Get the intent object through new intent (packagecontext, CLS), parameters: context, class bytecode

Call the startactivity (intent) method of the activity object

Activate the interface of the system program

How to get the full interface name of the system application? Clear the logcat, start the system application on the simulator, view the log, and find the information printed by the activitymanager

Get intent object

Call the setclassname (packagename, classname) method of the intent object to set the class name. Parameters: the package name of the application string type to be activated, and the class name of the string type

Call the startactivity (intent) method

The business scenario is to automatically locate the interface of network settings when checking the network

Check the user's network condition

Get the connectitymanager object and call the getsystemservice () method of the context object. Parameter: context. Connectivity_ SERVICE

Call the getactivenetworkinfo () method of the connectitymanager object to return the networkinfo object

Call the isconnected() method of the networkinfo object

Judge whether the networkinfo object is null and the return value of the above method to show toast

Permission android.permission.access required_ NETWORK_ STATE

There will be problems with the 4.0 system. We'll talk about it later