Nsurlconnection (ios2.0-ios9.0) Brief introduction

Nsurlconnection Four steps to use:

1, Prepare Url-nsurl

2. Create Request-Nsrequest

3. Sending requests (including asynchronous and synchronous)

4. Callback

1     //4 ways to create a request:2     //MARK:-Scenario One: Create Request object (default request length 60s)3     //nsurlrequest *request = [Nsurlrequest requestwithurl:url];4     5     //MARK:-Scenario Two: Create a Request object to set both the cache policy and the timeout length6     /*7 CachePolicy:8 nsurlrequestuseprotocolcachepolicy = 0, using the HTTP default cache policy9      Ten nsurlrequestreloadignoringlocalcachedata = 1, load only the latest network data (stock) One       A nsurlrequestreturncachedataelseload = 2, load cache first, then load network data -       - nsurlrequestreturncachedatadontload = 3, load only cached data (offline application: Offline map, offline video) the      */ -     //nsurlrequest *request = [nsurlrequest requestwithurl:url cachepolicy:0 timeoutinterval:15]; -      -     //MARK:-Scenario Three: Using Nsmutableurlrequest: You can modify the request method (default is get, you can change to post) +Nsmutableurlrequest *requestm =[Nsmutableurlrequest Requestwithurl:url]; -     //Requestm.httpmethod = @ "POST";//Modify to POST request +     //additional request header information, only variable (nsmutableurlrequest) to modify A[Requestm SetValue:@"IPhone AppleWebKit"Forhttpheaderfield:@"user-agent"]; at      -     //MARK:-Scenario IV: Similar to scenario two, with cache policy and timeout length on a scenario three basis -Nsmutableurlrequest *requestm2 = [Nsmutableurlrequest requestwithurl:url cachepolicy:0timeOutInterval: the];

 1  //  Nsurlresponse Description:  2  //  1, MIMEType: File type on server (Content-type inside equivalent response header)  3  //  2, Expectedcontentlength: The total size of the file on the server (used when downloading the progress calculation) . Span style= "COLOR: #008080" >4  //  3, suggest Edfilename: After the file is downloaded, the  5  // Span style= "COLOR: #008000" > subclass Nshttpurlresponse:  6  //  StatusCode: status code, 200 for success, 304 unmodified, to read from cache  

Below a complete small demo, use Nsurlconnection to load Baidu, and use WebView to display:

1 #import "ViewController.h"2 3 /*4 nsurlconnection use four steps:5 1, prepare Url-nsurl6 2. Create Request-Nsrequest7 3. Sending requests (including asynchronous and synchronous)8 4. Callback9  */Ten  One @interfaceViewcontroller () A  -@property (Weak, nonatomic) iboutlet UIWebView *WebView; -  the @end -  - @implementationViewcontroller -  +- (void) Viewdidload { - [Super Viewdidload]; + [self loaddata]; A } at  -  -- (void) loaddata{ -     //Prepare the URL -Nsurl *url = [Nsurl urlwithstring:@"https://www.baidu.com"]; -      in     //MARK:-Scenario One: Create Request object (default request length 60s) -     //nsurlrequest *request = [Nsurlrequest requestwithurl:url]; to      +     //MARK:-Scenario Two: Create a Request object to set both the cache policy and the timeout length -     /* the CachePolicy: * nsurlrequestuseprotocolcachepolicy = 0, using the HTTP default cache policy $      Panax Notoginseng nsurlrequestreloadignoringlocalcachedata = 1, load only the latest network data (stock) -       the nsurlrequestreturncachedataelseload = 2, load cache first, then load network data +       A nsurlrequestreturncachedatadontload = 3, load only cached data (offline application: Offline map, offline video) the      */ +     //nsurlrequest *request = [nsurlrequest requestwithurl:url cachepolicy:0 timeoutinterval:15]; -      $     //MARK:-Scenario Three: Using Nsmutableurlrequest: You can modify the request method (default is get, you can change to post) $Nsmutableurlrequest *requestm =[Nsmutableurlrequest Requestwithurl:url]; -     //Requestm.httpmethod = @ "POST";//Modify to POST request -     //additional request header information, only variable (nsmutableurlrequest) to modify the[Requestm SetValue:@"IPhone AppleWebKit"Forhttpheaderfield:@"user-agent"]; -     Wuyi     //MARK:-Scenario IV: Similar to scenario two, with cache policy and timeout length on a scenario three basis theNsmutableurlrequest *requestm2 = [Nsmutableurlrequest requestwithurl:url cachepolicy:0timeOutInterval: the]; -      Wu     //Parameter 1: Request Object -     //Parameter 2: Callback Queue About     //Parameter 3: Completion callback $[Nsurlconnection sendasynchronousrequest:requestm queue:[nsoperationqueue Mainqueue] completionHandler:^ ( Nsurlresponse * _nullable response, NSData * _nullable data, Nserror *_nullable Connectionerror) { -         //Response: Response header -         //Data: Response body (binary) -         //connectionerror: Error message A          +         //Nsurlresponse Introduction: the         //1. MIMEType: File type on server (Content-type in equivalent response header) -         //2. Expectedcontentlength: The total size of the file on the server (used when downloading the progress calculation) $         //3, suggestedfilename: File download down, save the name of the the         //sub-class Nshttpurlresponse: the         //StatusCode: status code, 200 = success, 304 unmodified, read from cache the          the         //MARK:-Judging the wrong way one -         /* in if (connectionerror! = nil) { the NSLog (@ "Network request error:%@", connectionerror); the return; About          } the nshttpurlresponse *httpurlresponse = (Nshttpurlresponse *) response; the if (Httpurlresponse.statuscode = = | | httpurlresponse.statuscode = = 304) { the NSLog (@ "Response head:%@", response); + NSLog (@ "Response body:%@", data); - nsstring *htmlstr = [[NSString alloc] Initwithdata:data encoding:nsutf8stringencoding]; the          Bayi [Self.webview loadhtmlstring:htmlstr baseurl:url]; the          } the          */ -         //MARK:-Judging the wrong way two -         if(Connectionerror = = Nil && Data! =Nil) { theNSLog (@"response header:%@", response); theNSLog (@"response body:%@", data); theNSString *htmlstr =[[NSString alloc] Initwithdata:data encoding:nsutf8stringencoding]; the              - [Self.webview loadhtmlstring:htmlstr baseurl:url]; the}Else{ theNSLog (@"Network request error:%@", connectionerror); the         }94     }]; the } the  the @end

Nsurlconnection (ios2.0-ios9.0) Brief introduction