NSURLConnection的Get\Post方法

#import "ViewController.h"

@interface ViewController () <NSURLConnectionDataDelegate>
@property (nonatomic, strong) NSMutableData *data;
@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

[self setupView];
}

- (void)setupView
{
[self connection];
}

- (void)connection
{
NSString *urlStr = [NSString stringWithFormat:@"这里存放所需要的url"];

//进行转码，以免中文乱码
urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSURL *url = [NSURL URLWithString:urlStr];

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
//设置请求超时时间
request.timeoutInterval = 10.0;

[self sendAsyncOnBlock:request];
}

//发送get请求，用block回调
- (void)sendAsyncOnBlock:(NSMutableURLRequest *)request
{
NSOperationQueue *queue = [NSOperationQueue mainQueue];

[NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

//注意，这里回调block的线程，我是设置为主线程的。因为往往，在这里面，需要更新UI界面，而在iOS开发中，
//更新UI界面必须在主线程中更新~~
//
//然后，解析json

if (data){  //请求成功
NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];   //解析数据

}
else{  //请求失败
//返回的json数据为空
}
}];
}

//使用代理方式，发送get请求
- (void)sendAsyncOnDelegate:(NSMutableURLRequest *)request
{
NSURLConnection *connection = [NSURLConnection connectionWithRequest:request delegate:self];
[connection start];
}

//发送post请求
- (void)sendPostReq
{
NSString *urlStr = [NSString stringWithFormat:@"这里存放所需要的url"];

//进行转码，以免中文乱码
urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSURL *url = [NSURL URLWithString:urlStr];

//设置为post请求
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];  //默认是get请求
request.HTTPMethod = @"POST";
request.timeoutInterval = 10.0;

//通过请求头，告知服务器，客户端的类型
[request setValue:@"ios" forHTTPHeaderField:@"User-Agent"];

//设置请求体:(必须要设置，没有具体数据，不做示范)
//    NSString *param = [NSString stringWithFormat:];
//    request.HTTPBody = [param dataUsingEncoding:NSUTF8StringEncoding];

//发送请求
NSOperationQueue *queue = [NSOperationQueue mainQueue];
[NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

}];
}

#pragma mark -- NSURLConnectionDataDelegate

//当接受到服务器的响应(连通了服务器)就会调用
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
self.data = [[NSMutableData alloc] init];
}

//请求错误(失败)的时候调用(请求超时\断网\没有网, 一般指客户端错误)
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{

}

//当接受到服务器的数据就会调用(可能会被调用多次, 每次调用只会传递部分数据)
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
//在这里，当下载大文件资源时，是需要拼接数据的
[self.data appendData:data];
}

//当服务器的数据接受完毕后就会调用
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{

}
@end