常用類
- NSURL:請求地址
- NSURLRequest:一個NSURLRequest對象就代表一個請求沪羔,它包含的信息有
一個NSURL對象
請求方法侦啸、請求頭碑宴、請求體
請求超時… …
- NSMutableURLRequest:NSURLRequest的子類
- NSURLConnection
- 負(fù)責(zé)發(fā)送請求梗肝,建立客戶端和服務(wù)器的連接
- 發(fā)送數(shù)據(jù)給服務(wù)器,并收集來自服務(wù)器的響應(yīng)數(shù)據(jù)
NSURLConnection的使用步驟
NSURLConnection發(fā)送請求
- NSURLConnection常見的發(fā)送請求方法有以下幾種
同步請求
+ (NSData *)sendSynchronousRequest:(NSURLRequest *)request returningResponse:(NSURLResponse **)response error:(NSError **)error;
異步請求:根據(jù)對服務(wù)器返回數(shù)據(jù)的處理方式的不同航背,又可以分為2種
block回調(diào)
+ (void)sendAsynchronousRequest:(NSURLRequest*) request? ? ? ? ? ? ? ? ? ? ? ? ? queue:(NSOperationQueue*) queue? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? completionHandler:(void (^)(NSURLResponse* response, NSData* data, NSError* connectionError)) handler;
代理
- (id)initWithRequest:(NSURLRequest *)request delegate:(id)delegate;
+ (NSURLConnection*)connectionWithRequest:(NSURLRequest *)request delegate:(id)delegate;
- (id)initWithRequest:(NSURLRequest *)request delegate:(id)delegate startImmediately:(BOOL)startImmediately;
在startImmediately = NO的情況下喉悴,需要調(diào)用start方法開始發(fā)送請求
- (void)start;
成為NSURLConnection的代理,最好遵守NSURLConnectionDataDelegate協(xié)議
NSURLConnectionDelegate
NSURLConnectionDataDelegate協(xié)議中的代理方法
開始接收到服務(wù)器的響應(yīng)時調(diào)用
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
接收到服務(wù)器返回的數(shù)據(jù)時調(diào)用(服務(wù)器返回的數(shù)據(jù)比較大時會調(diào)用多次)
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;
服務(wù)器返回的數(shù)據(jù)完全接收完畢后調(diào)用
- (void)connectionDidFinishLoading:(NSURLConnection *)connection;
請求出錯時調(diào)用(比如請求超時)
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;
NSMutableURLRequest
NSMutableURLRequest是NSURLRequest的子類玖媚,常用方法有
設(shè)置請求超時等待時間(超過這個時間就算超時粥惧,請求失敗)
- (void)setTimeoutInterval:(NSTimeInterval)seconds;
設(shè)置請求方法(比如GET和POST)
- (void)setHTTPMethod:(NSString *)method;
設(shè)置請求體
- (void)setHTTPBody:(NSData *)data;
設(shè)置請求頭
- (void)setValue:(NSString *)value forHTTPHeaderField:(NSString *)field;
創(chuàng)建GET和POST請求
// 創(chuàng)建GET請求
NSString *urlStr = [@"http://120.25.226.186:32812/login2?username=小碼哥&pwd=520it" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:urlStr];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
// 創(chuàng)建POST請求
NSString *urlStr = @"http://120.25.226.186:32812/login";
NSURL *url = [NSURL URLWithString:urlStr];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
request.HTTPMethod = @"POST";
// 請求體
NSString *bodyStr = @"username=520it&pwd=520it";
request.HTTPBody = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];
多值參數(shù)
- 有時候一個參數(shù)名最盅,可能會對應(yīng)多個值
http://120.25.226.186:32812/weather?place=Beijing&place=Henan&place=Hunan
- 服務(wù)器的place屬性是一個數(shù)組