iOS代码常用的代码片段

[self.tableView setContentOffset:CGPointMake(0, 0) animated:YES];

self.selectionStyle = UITableViewCellSelectionStyleNone;

arrData = [[arr reverseObjectEnumerator] allObjects];

//tableview没有数据的时候不显示线
_tableView.tableFooterView = [[UIView alloc] init];

tableView.separatorStyle = UITableViewCellSeparatorStyleNone

//获取屏幕 宽度、高度
#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"温馨提示" message:@"注册成功" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleCancel handler:nil];
[alertController addAction:alertAction];
[self.parentViewController presentViewController:alertController animated:YES completion:nil];

//使用NSURLSessionDataTask请求数据
- (void)loadData {

// 创建Data Task
NSURL *url = [NSURL URLWithString:@"http://192.168.41.48/~jenkins/Json/lottery.php"];

NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request
completionHandler:
^(NSData *data, NSURLResponse *response, NSError *error) {
// 输出返回的状态码，请求成功的话为200
NSDictionary *jsondic;
jsondic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
NSLog(@"%@",jsondic);

num = [[[jsondic objectForKey:@"result"] objectForKey:@"num"] integerValue];

[self startAnimation];

}];
[dataTask resume];
}