网络请求

新建一个工程

.h文件中

{

UIImageView *imagev;

}

@property(nonatomic,strong)NSMutableData *myData;//接收下载的数据

.m文件中

- (void)viewDidLoad {

[super viewDidLoad];

UIButton *getButton =[UIButton buttonWithType:UIButtonTypeCustom];

getButton.frame = CGRectMake(30, 40, 200, 40);

[self.view addSubview:getButton];

[getButton setTitle:@"同步GET" forState:UIControlStateNormal];

[getButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

getButton.layer.borderColor = [UIColor greenColor].CGColor;

getButton.layer.borderWidth = 0.3;

[getButton addTarget:self action:@selector(synchronizeGet) forControlEvents:UIControlEventTouchUpInside];

UIButton *postButton =[UIButton buttonWithType:UIButtonTypeCustom];

postButton.frame = CGRectMake(30, 90, 200, 40);

[self.view addSubview:postButton];

[postButton setTitle:@"同步POST" forState:UIControlStateNormal];

[postButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

postButton.layer.borderColor = [UIColor greenColor].CGColor;

postButton.layer.borderWidth = 0.3;

[postButton addTarget:self action:@selector(synchronizePost) forControlEvents:UIControlEventTouchUpInside];

UIButton *dailiButton =[UIButton buttonWithType:UIButtonTypeCustom];

dailiButton.frame = CGRectMake(30, 140, 200, 40);

[self.view addSubview:dailiButton];

[dailiButton setTitle:@"异步代理" forState:UIControlStateNormal];

[dailiButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

dailiButton.layer.borderColor = [UIColor greenColor].CGColor;

dailiButton.layer.borderWidth = 0.3;

[dailiButton addTarget:self action:@selector(yibuDelegata) forControlEvents:UIControlEventTouchUpInside];

UIButton *blockButton =[UIButton buttonWithType:UIButtonTypeCustom];

blockButton.frame = CGRectMake(30, 190, 200, 40);

[self.view addSubview:blockButton];

[blockButton setTitle:@"异步block" forState:UIControlStateNormal];

[blockButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

blockButton.layer.borderColor = [UIColor greenColor].CGColor;

blockButton.layer.borderWidth = 0.3;

[blockButton addTarget:self action:@selector(yibuBlock) forControlEvents:UIControlEventTouchUpInside];

imagev = [[UIImageView alloc]init];

imagev.frame = CGRectMake(10, 250, self.view.frame.size.width-20, 400);

imagev.backgroundColor = [UIColor redColor];

[self.view addSubview:imagev];

}

//同步get方法

//get是完全公开的网址是暴露的

//拿到网址的图片并显示到uiimageview上

//http://www.sinaimg.cn/dy/slidenews/4_img/2014_50/704_1502763_259801.jpg

//-(void)synchronizeGet

//{

// //获取网址

// NSString *str = @"http://www.sinaimg.cn/dy/slidenews/4_img/2014_50/704_1502763_259801.jpg";

// //将字符串转换成网址

// NSURL *url =[NSURL URLWithString:str];

// //创建请求

// //1参 URL网址

// //2参缓存方式(弊端:缓存到内存,数据量大的话会很占用内存,正确的应该缓存到本地)

// //3参请求超时时间

// NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];

// //设置请求方式

// // request.HTTPMethod =@"GET";//(这句也可以不写,因为默认就是get)

// //发送请求(同步请求)

// //1参 request请求

// //2参服务器响应信息

// //3参错误信息

// NSURLResponse *response = nil;//服务器信息

// NSError *error = nil;//错误信息

// // 程序会停在这里直到下载结束才会继续执行后面的代码所有就导致了APP假死现象

// NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];//用NSURLConnection发送,用一个data接收直到程序结束

// //展示到uiimageview上

// UIImage *image = [UIImage imageWithData:data];

// imagev.image = image;

//}

-(void)synchronizeGet

{

NSString *str = @"http://project.lanou3g.com/teacher/yihuiyun/lanouproject/activitylist.php";

NSURL *url =[NSURL URLWithString:str];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];

NSURLResponse *response = nil;

NSError *error = nil;

NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];//data是下载下来豆瓣的信息

//解析

//最外层是大括号字典

NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];

NSArray *array = [dic objectForKey:@"events"];

NSDictionary *dic1 = [array objectAtIndex:0];

NSLog(@"%@",[dic1 objectForKey:@"title"]);

for (NSDictionary *dic1 in array) {

NSLog(@"%@",[dic1 valueForKey:@"content"]);

}

//同步post方式请求数据

-(void)synchronizePost

{

//网址

NSString *str = @"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx";

NSURL *url =[NSURL URLWithString:str];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];

//设置请求方式

request.HTTPMethod =@"POST";

//需要携带body体 body中的内容是看不见的是一个nsdata格式的数据所以说post请求有保密性质但是现在很多的APP的post请求还是被一些抓包工具抓出来

NSString *bodyStr = @"date=20131129&startRecord=1&len=30&udid=1234567890&terminalType=Iphone&cid=213";//这段放保密信息

//将字符串转化成nsdata

NSData *data = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];//编码方式

//设置body体

request.HTTPBody = data;

//发送请求

NSURLResponse *response = nil;

NSError *error = nil;

NSData *resultData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

//将data转换成字符串

NSString *resultStr =[[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];

NSLog(@"%@",resultStr);

}

//异步代理(不会卡)

-(void)yibuDelegata

{

NSString *str =@"http://www.sinaimg.cn/dy/slidenews/4_img/2014_50/704_1502763_259801.jpg";

NSURL *url =[NSURL URLWithString:str];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];

//用代理下载

[NSURLConnection connectionWithRequest:request delegate:self];

//拿图片的URL

// NSData *data = [NSData dataWithContentsOfURL:<#(NSURL *)#>]

}

#pragma -mark 下载的代理方法(4个)

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response

{

//收到服务器的响应(初始化可变data)

self.myData = [NSMutableData data];

}

//收到服务器返回的数据

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data

{

[self.myData appendData:data];

}

//下载结束

-(void)connectionDidFinishLoading:(NSURLConnection *)connection

{

UIImage *image = [UIImage imageWithData:self.myData];

imagev.image = image;

}

//下载失败,错误会走的方法

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error

{

}

//异步block

-(void)yibuBlock

{

NSString *str = @"http://www.sinaimg.cn/dy/slidenews/4_img/2014_50/704_1502763_259801.jpg";

NSURL *url = [NSURL URLWithString:str];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];

//发送异步block请求

//程序走到这一行发送请求不会卡住继续执行下面的代码当加载结束之后走block里面的代码

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

//下载结束之后走这里

//block里面三个参数: 服务器响应信息下载的data 错误信息

//展示到uiimageview上

UIImage *image = [UIImage imageWithData:data];

imagev.image = image;

}];

}

效果图: