我正在尝试构建一个表视图控制器,该控制器在查看时从数据库加载数据。
在向用户显示该数据后,该表轮询 Web 服务以获取更新,而数据对用户可见,并在 Web 服务响应时重新加载。
这是控制器:
- (void) viewDidAppear:(BOOL)animated
{
NSLog(@"in view did appear");
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:@"menuView" bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// make space between the start of the screen and the start of th table
[self.tableView setContentInset:UIEdgeInsetsMake(80,0,0,0)];
// connect to database
database = [[connectToDB alloc] init];
[database setDelegate:self];
// fill the table from the DB
[database selectSqlQuere:@"SELECT * FROM ZTASKS"];
// refresh when table scroll down
UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
[refreshControl addTarget:self action:@selector(refresh:) forControlEvents:UIControlEventValueChanged];
[self.tableView addSubview:refreshControl];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
@end
如何在轮询 Web 服务时保持表格对用户可见,并在 Web 服务响应时更新表格?