Question

当URL请求成功完成后，如何将用户定向到定义的View Controller。我有一个带有用户名和密码字段的登录页面。以下是我的代码。任何帮助非常感谢。

#import "LoginTableViewController.h"

@interface LoginTableViewController ()
@property (weak, nonatomic) IBOutlet UITextField *UIEmailTextField;
@property (weak, nonatomic) IBOutlet UITextField *UIPasswordTextField;

@end

@implementation LoginTableViewController
@synthesize UIEmailTextField;
@synthesize UIPasswordTextField;

- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
    // Custom initialization
}
return self;
}

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

- (void)viewDidUnload
{
[self setUIEmailTextField:nil];
[self setUIPasswordTextField:nil];
[super viewDidUnload];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark - barButton Outlet

- (IBAction)loginButtonPressed:(UIBarButtonItem *)sender {
NSString *data = [NSString stringWithFormat:@"username=%@&password=%@",UIEmailTextField.text, UIPasswordTextField.text];
NSData *postData = [data dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

// preaparing URL request to send data.

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
NSString *url = [NSString stringWithFormat:@"http://www.twitter.com"];
[request setURL:[NSURL URLWithString:url]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setHTTPBody:postData];
[request setTimeoutInterval:7.0];

NSURLResponse *response;
NSError *error;

NSData *urlData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSString *str=[[NSString alloc]initWithData:urlData encoding:NSUTF8StringEncoding];

NSLog(@"Login response:%@",str);

NSLog(@"Log In button was pressed!");
}

@end

Answer 1

现在你设置它的方式，你的NSURLConnection将阻塞主线程直到它完成。如果您使用异步NSURLConnection，您可以成为它的委托并适当地响应失败和成功，如下所示：

NSURLConnection* connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];  //Conform to NSURLConnectionDelegate before you use this.

-(void)connection:(NSURLConnection*)connection didReceiveResponse:(NSURLResponse*)response
{
    //Got a response.  Not necessarily an error, so login might have been successful,
    //or it might not have.
}
-(void)connection:(NSURLConnection*)connection didReceiveData:(NSData*)data
{
    //The connection returned data.  Really only useful for requesting files.
}
-(void)connection:(NSURLConnection*)connection didFailWithError:(NSError*)error
{
    //Handle the error properly
}
-(void)connectionDidFinishLoading:(NSURLConnection*)connection
{
    //Connection's finished completely.  Probably a good time to check for an error,
    //Or change the view controller 
}

另外，更多的旁注，属性应该 NOT 以ObjC中的大写字母开头，这就是类使用的情况。并且明智的做法是不要使用变量名称的UI命名空间。 的

Answer 2

如果您正在尝试登录页面，我建议采用不同的方法：将成功登录的页面放在首位，然后将其设置为根视图控制器。然后，立即将登录控制器作为模态控制器推送。这样，即使登录失败，您也可以再次按下登录屏幕。如果您允许用户保留其凭据而不必在启动后再次登录（如果适用），这也会清除您的代码。无论如何，这是一种更清洁的方法。您没有rootViewController级别的登录屏幕。

Answer 3

设置视图控制器，以便在成功登录后解除LoginTableViewController将显示相应的视图控制器。

例如：

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    UIViewController *rootViewController = [[UIViewController alloc] init];
    self.window.rootViewController = rootViewController;

    LoginTableViewController *loginViewController = [[LoginTableViewController alloc] init];
    [rootViewController presentViewController:loginViewController animated:NO completion:nil];

    return YES;
}

登录成功后，请关闭LoginTableViewController：

[self dismissViewControllerAnimated:YES completion:nil];

登录成功Xcode后转到View Controller

3 个答案: