IOS Study Notes 26-http operations-asihttprequest (2)

Asihttprequest can also be used to submit request parameters to the server. In this example, the client sends an XML request and obtains the response from the server. The response is an XML string. Go to the Code directly. The Code has detailed comments.

First, make the following statement in the. h file:

#import <UIKit/UIKit.h>@interface ViewController : UIViewController@property (retain,nonatomic) UIActivityIndicatorView *indicator;@property (retain, nonatomic) IBOutlet UITextField *userNameTextField;@property (retain, nonatomic) IBOutlet UITextField *passwordTextField;- (IBAction)login:(id)sender;@end

Then the. m implementation file (only the main code section is listed here ):

// Use the asynchronous request and update the UI-(ibaction) login :( ID) sender {// The loading prompt box [self showtoast: @ "logging in... "];/* run the login request. The server uses XML for a servelet request running on Tomcat. The format is as follows: <document> <user id = "XXX" Password = "XXX"/> </document> the request result returns an XML string. I have omitted the server address here, because the server of the previous project is used, it cannot be disclosed here */_ block asihttprequest * request = [[asihttprequest alloc] initwithurl: [nsurl urlwithstring: @ "http: // xxx/Server/login "]; // construct a variable string request nsmutablestring * requestxml = [[nsmutablestring alloc] init]; [requestxml appendstring: @ "<document>"]; [requestxml appendstring: @ "<user id = \" "]; [requestxml appendstring: Self. usernametextfield. text]; [requestxml appendstring: @ "\" "]; [requestxml appendstring: @" Password = \ ""]; [requestxml appendstring: Self. passwordtextfield. text]; [requestxml appendstring: @ "\"/> "]; [requestxml appendstring: @" </document> "]; // converts the nsstring type to the nsdata type, the following parameter is the encoding type, here is the UTF-8 nsdata * requestdata = [requestxml datausingencoding: nsutf8stringencoding]; // method using the custom request parameter in asihttprequest [Request appendpostdata: requestdata]; // set the request method [Request setrequestmethod: @ "Post"]; // after the request is executed, the code in the block will be called [Request setcompletionblock: ^ {nslog (@ "success "); nslog (@ "% @", [Request responsestring]); [self. indicator stopanimating]; [alertview dismisswithclickedbuttonindex: 0 animated: Yes]; [self. indicator release]; [alertview release];}]; // if an exception occurs, the code in the block will be executed [Request setfailedblock: ^ {nslog (@ "failed"); [self. indicator stopanimating]; [alertview dismisswithclickedbuttonindex: 0 animated: Yes]; [self. indicator release]; [alertview release];}]; [Request startasynchronous]; [request release];} // create a custom pop-up prompt box-(void) showtoast :( nsstring *) message {alertview = [[uialertview alloc] initwithtitle: Message message: Nil delegate: Self cancelbuttontitle: Nil failed: nil, nil]; [alertview setbackgroundcolor: [uicolor clearcolor]; // The Show method must be called here; otherwise, indicator is not in uialerview [alertview show]; self. indicator = [[uiactivityindicatorviewalloc] initwithactivityindicatorstyle: uiactivityindicatorviewstylewhitelarge]; self. indicator. center = cgpointmake (alertview. bounds. size. width/2, alertview. bounds. size. height-40); // hide indicator self when stopping. indicator. hideswhenstopped = yes; // put uiactivityindicator as a sub-control in uialertview [alertview addsubview: Self. indicator]; [self. indicator startanimating];}

Let's take a look at the running effect and the returned information of the server:

After clicking log on, you can view the logon result returned by the server on the console:

The above is a small example of using asihttprequest to send data to the server and obtain the returned results. Using asihttprequest, there are many other powerful functions. You can refer to the official documentation for specific usage and usage.

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