Super slow lag/delay on initial keyboard animation of UITextField

Question

It takes roughly 3-4 seconds for the keyboard to pop up after I touch my UITextField. This only occurs on the first time the keyboard pops up since the app launched, afterwards the animation starts instantly.

At first I thought it was problem of loading too many images, or my UITableView, but I just created a brand new project with only a UITextField, and I still experience this problem. I'm using iOS 5, Xcode ver 4.2, and running on an iPhone 4S.

This is my code:

#import "ViewController.h"

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(20, 20, 280, 30)];
    textField.borderStyle = UITextBorderStyleRoundedRect;
    textField.delegate = self;
    [self.view addSubview:textField];
}

@end

Is this a common problem for all apps?

Right now, the only way I can make it somewhat better is by having textField become/resign first responder in viewDidAppear, but that doesn't solve the problem entirely - it just loads the delay onto when the view loads instead. If I click on textField immediately when the view loads, I still get the problem; if I wait 3-4 seconds after the view loads before touching the textField, I don't get the delay.

Answer 1

Before you implement any exotic hacks to get around this problem, try this: stop the debug session, close the app from multitasking, unplug your device from the computer and run the app normally by tapping its icon. I have seen at least two cases in which the delay only occurs while the device is plugged in.

Answer 2

So the problem is NOT just limited to the first install as I had previously thought, but happens every time the app is launched. Here's my solution that solves the issue completely.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  // Preloads keyboard so there's no lag on initial keyboard appearance.
  UITextField *lagFreeField = [[UITextField alloc] init];
  [self.window addSubview:lagFreeField];
  [lagFreeField becomeFirstResponder];
  [lagFreeField resignFirstResponder];
  [lagFreeField removeFromSuperview];
}

Answer 3

Yeah, I also got a few seconds delay on the latest iPhone 4s. Don't panic. For some reasons, it only happens the first time the app is loaded from Xcode in Debug. When I did Release, I don't get the delay. Just forget it...

Answer 4

You can use Vadoff's solution in Swift by adding this to didFinishLaunchingWithOptions:

// Preloads keyboard so there's no lag on initial keyboard appearance.
let lagFreeField: UITextField = UITextField()
self.window?.addSubview(lagFreeField)
lagFreeField.becomeFirstResponder()
lagFreeField.resignFirstResponder()
lagFreeField.removeFromSuperview()

It is working for me in iOS 8.

Answer 5

Code in block added to main queue and run asynchronously. (don't locked main thread)

dispatch_async(dispatch_get_main_queue(), ^(void){
      [textField becomeFirstResponder];
 });

Answer 6

This bug seems to be fixed in iOS 9.2.1. Since upgrading my device, I no longer have a delay between tapping a text field and the keyboard appearing when my device is connected to my computer.

Answer 7

You can add below code when viewController's view did loaded, like viewDidAppear.Not just application:didFinishLaunchingWithOptions:

UITextField *lagFreeField = [[UITextField alloc] init];
[self.window addSubview:lagFreeField];
[lagFreeField becomeFirstResponder];
[lagFreeField resignFirstResponder];
[lagFreeField removeFromSuperview];