ios - 当导航到另一个页面时需要添加事件指示器

Question

#import "LoginVC.h"
#import "HOMEVC.h"
#import "DashboardVC.h"
@interface LoginVC ()

@end

@implementation LoginVC
UIActivityIndicatorView *spinner ;
-(IBAction)login:(id)sender{

    NSString *userUpdate =[NSString stringWithFormat:@"%@",[Usernamefileld text]];
    NSString *userUpdate1 =[NSString stringWithFormat:@"%@",[PasswordField text]];
    NSString *baseURL = [NSString stringWithFormat:@"http://192.168.1.200:8094/YazakiService.svc/LOGIN/%@/%@",userUpdate,userUpdate1];
    NSURL *url = [NSURL URLWithString:[baseURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    NSURLResponse *response;
    NSError *error;
    NSData *responseData =[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
    NSMutableArray *serviceResponse=[NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:&error];
    NSLog(@"got response==%@", serviceResponse);
    NSDictionary *template=[serviceResponse objectAtIndex:0];

    NSString *test=[template objectForKey:@"ValidState"];
    // NSString *test1=[template objectForKey:@"Userid"];
    NSString *helloString = @"1";
    //   //
    //   NSString *helloString1 =@"LFY430";
    if ([test isEqual:helloString]) {
        [NSThread detachNewThreadSelector:@selector(threadStartAnimating:) toTarget:self withObject:nil];
        [self moveToView];

        //        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"Login Successfully" message:@"Correct Uername/Password" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    }
    else{

        UIAlertView *alert2=[[UIAlertView alloc]initWithTitle:@"Login Failed" message:@"Incorrect Uername/Password" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];

        [alert2 show];
        [self alertView1:alert2 didDismissWithButtonIndex:alert2];

    }

}

- (void)viewDidLoad {

    [super viewDidLoad];
    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(150, 225, 20, 30)];
    [spinner setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleGray];
    spinner.color = [UIColor blackColor];
    [self.view addSubview:spinner];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

-(void)moveToView{

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];


    DashboardVC *initView =  (DashboardVC*)[storyboard instantiateViewControllerWithIdentifier:@"Dashboardvc"];

    [initView setModalPresentationStyle:UIModalPresentationFullScreen];

    [spinner stopAnimating];
    [self presentViewController:initView animated:NO completion:nil];
}


- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    [self moveToView];
}

- (void) alertView1:(UIAlertView *)alertView1 didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    LoginVC *initView =  (LoginVC*)[storyboard instantiateViewControllerWithIdentifier:@"loginvc"];
    [initView setModalPresentationStyle:UIModalPresentationFullScreen];
    [self presentViewController:initView animated:NO completion:nil];
}
-(void)threadStartAnimating:(id)data
{
    [spinner startAnimating];
}


@end

在这里，我初始化了指示器并启动和停止旋转器，但它对我来说不起作用......任何人都可以帮助我解决如何在导航另一个 View 时添加事件指示器的问题

提前致谢

Answer 1

[self.view addSubview:spinner];

在这一行，您将事件指示器添加到当前的 ViewController View 。

但是一旦你导航到其他 View

DashboardVC *initView =  (DashboardVC*)[storyboard instantiateViewControllerWithIdentifier:@"Dashboardvc"];
[self presentViewController:initView animated:NO completion:nil];

当前 View 更改为新 ViewController 的 View 。该 View 中不存在事件指示器，因此您不会在那里看到您的事件指示器。

要解决，你应该在第二个 ViewController 的 viewDidLoad 方法中再次添加事件指示器在仪表板 VC 中

- (void)viewDidLoad {

    [super viewDidLoad];
    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(150, 225, 20, 30)];
    [spinner setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleGray];
    spinner.color = [UIColor blackColor];
    [self.view addSubview:spinner];
}

A better solution would be to use third party progress huds which make the loading indicator part absolutely easy like MBProgressHUD