iOS 使用URLSession实现网络请求

//下载搜索全文数据
NSString *string=[NSString stringWithFormat:@"%@Ajax/AjaxSearchBook.ashx?BookId=%@&No=0&SearchContent=%@",PhoneUrl,self.bookModel.BookID,searchBar.text];

NSString *urlString=[string stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];

NSURL *url=[NSURL URLWithString:urlString];

NSURLRequest *request=[NSURLRequest requestWithURL:url];

NSURLSession *session=[NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]
                                                    delegate:self
                                               delegateQueued];;

NSURLSessionDataTask *dataTask=[session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
    NSArray *array=[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
    
    if (array.count>0)
    {
        [searchDataArray removeAllObjects];
        
        for (NSDictionary *dic in array)
        {
            [searchDataArray addObject:dic];
        }
        
        //回到主线程
        dispatch_async(dispatch_get_main_queue(), ^{
            isSeacrhAll=YES;
            
            [searchTableView reloadData];
        });
    }
    
}];

//执行下载
[dataTask resume];