iOS 开发中所需的数据基本都是来自网络,网络数据请求是 iOS 编程中必不可少的,应该熟练掌握网络请求.
网络请求方式有 :GET , POST , PUT ,DELETE 等,其中常用的就是 GET,POST . GET 和 POST 请求存在着不同,GET 将数据参数跟在 URL 后面,POST 参数放在 body 中,不可见.
数据请求方式分为同步请求和异步请求,其中常用的是异步请求,异步请求避免了因组线程阻塞而造成的崩溃.这里主要说下异步请求.
1.GET 同步请求 用 NSURLConnection 实现:
步骤:建立 request ----> 建立衔接请求数据 ------> 解析数据
代码:
1 #pragma mark --- get 同步 ---
2 - (IBAction)getOne:(id)sender {
3 self.allNewsArray = [[NSMutableArray alloc]init];
4 //url 地址
5 NSURL *url = [NSURL URLWithString:PATH];
6 //请求
7 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
8 //建立衔接请求数据
9 NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
10 //如果数据不为空就解析
11 if (data) {
12 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:1 error:nil];
13 //处理数据,用 model 存储
14 for (NSDictionary *dic1 in [dic objectForKey:@"news"]) {
15 NewsModel *model = [[NewsModel alloc]init];
16 [model setValuesForKeysWithDictionary:dic1];
17 [self.allNewsArray addObject:model];
18 }
19
20 }
21 }
2.GET 异步请求 BLOCK 形式 用 NSURLConnection 实现
1 #pragma mark --- get 异步请求 ---
2 - (IBAction)getTwo:(id)sender {
3
4 self.allNewsArray = [[NSMutableArray alloc]init];
5 //url 地址
6 NSURL *url = [NSURL URLWithString:PATH];
7 //请求
8 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
9 //默认是 get 方法,如果是 get 方法可以不写
10 [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {
11 if (data) {
12 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
13 //处理数据,用 model 存储
14 for (NSDictionary *dic1 in [dic objectForKey:@"news"]) {
15 NewsModel *model = [[NewsModel alloc]init];
16 [model setValuesForKeysWithDictionary:dic1];
17 [self.allNewsArray addObject:model];
18 }
19 }
20
21 }];
22 }
3.POST 异步请求 BLOCK 形式:用 NSURLConnection 实现
1 #pragma mark --- POST 异步 Block 形式 ---
2 - (IBAction)POSTBlock:(id)sender {
3
4 NSURL *URL = [NSURL URLWithString:@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"];
5 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
6
7 //制作包体
8 NSString *param = @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";
9
10 NSData *data = [param dataUsingEncoding:NSUTF8StringEncoding];
11
12 //设置请求方式
13 [request setHTTPMethod:@"POST"];
14 //设置 body
15 [request setHTTPBody:data];
16 [request setTimeoutInterval:60];
17
18
19 //建立连接.请求数据
20 [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {
21
22 //解析数据
23 if (data) {
24 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
25 //处理数据,用 model 存储
26 for (NSDictionary *dic1 in [dic objectForKey:@"news"]) {
27 NewsModel *model = [[NewsModel alloc]init];
28 [model setValuesForKeysWithDictionary:dic1];
29 [self.allNewsArray addObject:model];
30 }
31 }
32
33 }];
34 }
4.POST 异步请求 delegate 形式:用 NSURLConnection 实现
1 - (IBAction)POST_Delegate:(id)sender {
2
3 NSURL *URL = [NSURL URLWithString:@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"];
4
5 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
6
7 //制作包体
8 NSString *param = @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";
9
10 NSData *data = [param dataUsingEncoding:NSUTF8StringEncoding];
11
12 //设置请求方式
13 [request setHTTPMethod:@"POST"];
14 //设置请求 body
15 [request setHTTPBody:data];
16
17 //建立连接请求数据
18 NSURLConnection *conn = [[NSURLConnection alloc]initWithRequest:request delegate:self];
19
20 //启动请求
21 [conn start];
22 }
23
24 - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
25 NSLog(@"接收到响应");
26
27 self.data = [NSMutableData data];
28
29 }
30
31 #pragma mark --- 接收数据的方法 ---
32 - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
33 [self.data appendData:data];
34 }
35
36 #pragma mark --- 结束传递数据 ---
37 - (void)connectionDidFinishLoading:(NSURLConnection *)connection{
38
39 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:self.data options:1 error:nil];
40 NSLog(@"%@",dic);
41
42 }
43
44
45 - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
46
47 }
5.GET 异步请求 SESSION 写法
1 #pragma mark --- GET Session 写法 ---
2 - (IBAction)session:(id)sender {
3
4 //创建 session 对象
5 NSURLSession *session = [NSURLSession sharedSession];
6
7 NSURL *URL = [NSURL URLWithString:PATH];
8
9 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
10
11 NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
12
13 if(data){
14 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
15
16 NSLog(@"%@",dic);
17 }
18 }];
19
20 //开始请求 (一定要调用)
21 [task resume];
22 }
6.POST 异步请求 BLOCK 形式:用 NSURLSession 实现
1 - (IBAction)POST_Session:(id)sender {
2
3 NSURL *URL = [NSURL URLWithString:@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"];
4
5 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
6
7 //制作包体
8 NSString *param = @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";
9
10 NSData *data = [param dataUsingEncoding:NSUTF8StringEncoding];
11
12 //设置请求方式
13 [request setHTTPMethod:@"POST"];
14 //设置请求 body
15 [request setHTTPBody:data];
16
17 NSURLSession *session = [NSURLSession sharedSession];
18 NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
19 NSLog(@"%@",error);
20
21 NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:1 error:nil];
22 NSLog(@"%@",dic);
23 }];
24
25 [task resume];
26 }
原文：http://www.cnblogs.com/Ager/p/4941055.html