IOS-----Detect Network Status

iOS not only built rich network communication APIs to develop network communication applications, but also supported a large number of third-party network communication APIs, fully support TCP, UDP network communication,

You can refer to Apple's official documentation for information on using Cfnetwork for UDP protocol communication.

Two third-party network communication frameworks on the iOS platform: afnetworking and ASIHTTPRequest, both of which are highly encapsulated in the iOS network communication API, allowing for more

Simple programming to achieve network communication

Detecting Network StatusCheck network status

The following two steps are required to check the network status of a device.

1	Download, add reachability class Reachability.zip compressed packages can be downloaded via https://developer.apple.com/library/ios/samplecode/Reachability/Reachability.zip link, Extracting the package will get a Xcode project You can also search for reachability through the Xcode help group system, then you can see the Reachability sample project in the "Sample Code" section, select the "reachability" list item to view Reachability project Click the Open Project button to open the project
2	Add a systemconfiguration.framework framework to a project
Code Snippets	1 VIEWCONTROLLER.M2 3 #import"ViewController.h"4 5 #import"Reachability.h"6 7 @implementationViewcontroller8 9- (void) ViewdidloadTen One { A - [Super Viewdidload]; - the } - - - + //Test Network Status - +-(Ibaction) Testnetstatus: (ID) Sender A at { - -nsstring* site =Self.siteFiled.text; - - //Create a reachability that accesses the specified site - inreachability* reach =[reachability reachabilitywithhostname:site]; - to //determine the network status of the device + - Switch([reach Currenreachabilitystatus]) the * { $ Panax Notoginseng //Cannot access - the Casenotreachable: + A[Self showalert:[nsstring stringwithformat:@ "cannot access%@ ", site]"; the + Break; - $ //using the 3G/4G network $ - CaseReachableviawifi: - the[Self showalert:[nsstring stringwithformat:@] Use 3g/4g network access%@ ", site]"; - Wuyi Break; the - //Use WiFi network Wu - CaseReachableviawwan: About $[Self showalert:[nsstring stringwithformat:@] Use 3g/4g network access%@ ", site]"; - - Break; - A } + the } - $ the the //Test WiFi the the-(Ibaction) Testwifi: (ID) Sender - in { the the if([[Reachability Reachabilityforlocalwifi] currentreachabilitystatus]! =notreachable) About the { the the [self showalert:@ "WiFi network is already connected"]; + - } the Bayi Else the the { - - [self showalert:@: "WiFi network is not available"]; the the } the the } - the the the //Test your mobile network94 the-(Ibaction) Testinternet: (ID) Sender the the {98 About if([[Reachability reachabilityforinternetconnection] currentreachabilitystatus]! =notreachable) - 101 {102 103[Self showalert:@] 3g/4G Network is connected "];104 the }106 107 Else108 109 { the 111[Self showalert:@] 3g/4G Network not available "]; the 113 } the the } the 117- (void) Showalert: (nsstring*) msg118 119 { - 121uialertview* alert = [[Uialertview alloc] initwithtitle:@ "Network status" message:msgDelegate: nil cancelbuttontitle:@ "OK" otherbuttontitles:nil];122 123 [alert show];124 the }126 127 @end
Description	The above program first calls the Reachability class's Reachabilitywithhostname: Class method to get the Reachability object, The object's Currentreachabilitystatus method is then called to get access to the specified site, which returns the NetworkStatus enumeration value, which has the following 3: typedef enum{ notreachable = 0,//No connection reachableviawifi,//using 3G/4G Network Reachableviawwan//Use WiFi } networkstatus; Therefore, the above program will judge the return value of the Currentreachabilitystatus method of reachability, so that the application can get the state and mode of accessing the network.

Monitor network status changes

After the program obtains the Reachability object, the Reachability object's Startnotifier method is called to turn on the object's listening state-------when the reachability

When a continuous state changes, the object sends a KREACHABILITYCHANGEDNOTIFICATION notification to the default notification hub, so the program uses only the default notification

The heart listens to the notification.

To listen for changes in the state of the network, add the following code to the Application:didfinishlaunchingwithoptions: method of the application delegate class.

code snippet	APPDELEGATE.M // Use notification hubs to listen for kreachabilitychangednotification notifications [[nsnotificationcenter Defaultcenter] addobserver:self selector: @selector (reachabilitychanged:) name:kreachabilitychangednotification object :nil]; // reachability * reach = [reachability reachabilitywithhostname:@ "www.baidu.com"]; // [reach Startnotifier];
Description	The code above uses the default notification hubs to detect kreachabilitychangednotification notifications, which means that when reachability's connection status changes, the default notification center receives the notification. This triggers the reachabilitychanged: Method of the application delegate class, so you also need to define the following methods in the application delegate class.
Code Snippets	1 APPDELEGATE.M2 3- (void) reachabilitychanged: (Nsnotification *) Noto4 5 {6 7 //gets the reachability object being monitored by a notification object8 9reachability *curreach = [NoteObject];Ten One //gets the network state of the Reachability object A -NetworkStatus status =[Curreach currentreachabilitystatus]; - the if(Status = =notreachable) - - { - +Uialertview *alert = [[Uialertview alloc] initwithtitle:@ "Reminder" message:@ "Cannot access www.baidu.com"Delegate: Nil cancelbuttontitle:@ "YES" otherbuttontitles:nil]; - + [alert show]; A at } - -}
Description	As you can see from the code above, this example listens to the Reachability object that accesses www.baidu.com, and when the object state is notreachable, the program uses Uialertview for reminders.

IOS-----Detect Network Status