iOS_網絡請求_代理方式

#pragma mark - 網絡請求代理方式（異步）


(IBAction)DelegateButtonDidClicked:(UIButton *)sender {
// 1、拼接 urlString,網址里面必須寫 http://
  NSString *urlString = @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx?date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";
// 2、根據字符串創建 URL(統一資源定位符)
  NSURL *url = [NSURL URLWithString:urlString];
// 3、根據 url 創建 request 請求類的對象
  NSURLRequest *request = [NSURLRequest requestWithURL:url];
// 4、請求數據（代理回調方式）遵守代理 <NSURLConnectionDataDelegate>
  [NSURLConnection connectionWithRequest:request delegate:self];
}</pre> 

 代理方法 

 客戶端收到服務器的響應 
#pragma mark | 客戶端收到服務器的響應


(void)connection:(NSURLConnection )connection didReceiveResponse:(NSURLResponse )response
{
  // 只執行一次
  // 初始化 receiveData 對象
  self.receiveData = [NSMutableData data];
}</pre> 

 
 客戶端收數據(并非一次性全部拿到) 
 
#pragma mark | 客戶端收數據(并非一次性全部拿到)
(void)connection:(NSURLConnection )connection didReceiveData:(NSData )data
{
  // 每次返回的都是新數據
  // 拼接數據(請求一點 拼接一點)
  [self.receiveData appendData:data];
}</pre> 

 
 客戶端接收數據完畢 
 
#pragma mark | 客戶端接收數據完畢
(void)connectionDidFinishLoading:(NSURLConnection )connection
{
  // 解析數據
  NSDictionary dict = [NSJSONSerialization JSONObjectWithData:self.receiveData options:(NSJSONReadingMutableContainers) error:nil];


NSArray *array = dict[@"news"];

self.newsArray = [NSMutableArray array];

for (NSDictionary *smallDict in array) {
    NewsModal *modal = [[NewsModal alloc] init];
    [modal setValuesForKeysWithDictionary:smallDict];
    [self.newsArray addObject:modal];
}

for (NewsModal *modal in self.newsArray) {
    NSLog(@"%@", modal.title);
}

}</pre> 

 網絡請求失敗
#pragma mark | 網絡請求失敗


(void)connection:(NSURLConnection )connection didFailWithError:(NSError )error
{
  NSLog(@"%@", error);
}</pre>