[NSURLSession/Delegate]用Post方式获取网络数据并把数据显示到表格

#pragma mark 实现NSURLSessionDataDelegate代理
@interface ViewController ()<UITableViewDataSource,UITableViewDelegate,NSURLSessionDataDelegate>
{
UIButton* sessionPostButton;
UIButton* sessionDelegatePostButton;
UITableView* table;
NSMutableArray* array;
NSMutableData* mutableData;
}
@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

sessionPostButton=[[UIButton alloc]initWithFrame:CGRectMake(30, 500, 80, 40)];
sessionPostButton.backgroundColor=[UIColor orangeColor];
[sessionPostButton setTitle:@"Session" forState:UIControlStateNormal];
[sessionPostButton addTarget:self action:@selector(sessionPostData) forControlEvents:UIControlEventTouchUpInside];

sessionDelegatePostButton=[[UIButton alloc]initWithFrame:CGRectMake(210, 500, 80, 40)];
sessionDelegatePostButton.backgroundColor=[UIColor orangeColor];
[sessionDelegatePostButton setTitle:@"Delegate" forState:UIControlStateNormal];
[sessionDelegatePostButton addTarget:self action:@selector(sessionDelegatePostData) forControlEvents:UIControlEventTouchUpInside];

table=[[UITableView alloc]initWithFrame:CGRectMake(0, 20, 320, 568-20) style:UITableViewStylePlain];
table.dataSource=self;
table.delegate=self;

[self.view addSubview:table];
[self.view addSubview:sessionPostButton];
[self.view addSubview:sessionDelegatePostButton];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section;
{
return array.count;
}

#pragma mark 表示每一行显示什么数据
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
{
//内存优化
static NSString * identity=@"cell";
//tableview 根据标识复制出一个cell
UITableViewCell * cell=[tableView dequeueReusableCellWithIdentifier:identity];
if (cell==nil) {
cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:identity];
}
NSDictionary* dic=array[indexPath.row];
cell.textLabel.text=[dic valueForKey:@"title"];
cell.detailTextLabel.text=[dic valueForKey:@"type"];
cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
return  cell;
}

-(void)sessionPostData
{
NSLog(@"sessionPost");
//创建NSString用来存储请求的网址
NSString* str=@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx";
//用UTF8String格式转换成NSURL
NSURL* url=[NSURL URLWithString:[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
//创建请求
NSMutableURLRequest* request=[[NSMutableURLRequest alloc]initWithURL:url];
[request setHTTPMethod:@"POST"];
//设置参数
NSString* where=@"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";
NSData* data=[where dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:data];
//创建session对象 单例
NSURLSession* session=[NSURLSession sharedSession];
//发送请求
NSURLSessionTask* task=[session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
if (data) {
//处理数据
NSDictionary* dic=[NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
array=[dic valueForKey:@"news"];
[table reloadData];
}
if (error) {
NSLog(@"%@",[error description]);
}
}];
[task resume];
}

-(void)sessionDelegatePostData
{
NSLog(@"sessionDelegatePost");
//创建NSString用来存储请求的网址
NSString* str=@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx";
//用UTF8String格式转换成NSURL
NSURL* url=[NSURL URLWithString:[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
//创建请求
NSMutableURLRequest* request=[[NSMutableURLRequest alloc]initWithURL:url];
[request setHTTPMethod:@"POST"];
//设置参数
NSString* where=@"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";
NSData* data=[where dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:data];
//默认的session配置 从网络读取数据
NSURLSessionConfiguration* config=[NSURLSessionConfiguration defaultSessionConfiguration];
//遵守delegate
NSURLSession* session=[NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];
//发送请求
NSURLSessionDataTask* task=[session dataTaskWithRequest:request];
//初始化接收数据的容器
mutableData=[NSMutableData data];
//开始任务
[task resume];
}

#pragma mark NSURLSessionDataDelegate中的方法
//#pragma mark 是否收到服务器响应 该方法不实现 实现后和后面方法冲突 用来测试服务器响应使用
//- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask
//didReceiveResponse:(NSURLResponse *)response
// completionHandler:(void (^)(NSURLSessionResponseDisposition disposition))completionHandler;
//{
//    NSLog(@"连接服务器成功");
//}

#pragma mark 服务器开始传输数据 反复调用本方法
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask
didReceiveData:(NSData *)data;
{
NSLog(@"正在传输数据");
[mutableData appendData:data];
}

#pragma mark 客户端接收数据完成时调用此方法
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask
willCacheResponse:(NSCachedURLResponse *)proposedResponse
completionHandler:(void (^)(NSCachedURLResponse * __nullable cachedResponse))completionHandler;
{
NSLog(@"数据传输完成");
NSDictionary* dic=[NSJSONSerialization JSONObjectWithData:mutableData options:NSJSONReadingMutableContainers error:nil];
array=[dic valueForKey:@"news"];
[table reloadData];
}