Hello everyone.
There is a problem that has bothered me for a long time recently.
I have two controllers, let's call them controllerA and controllerB. When I click some button in controllerA, I want to push controllerB into the navigation. Besides, I need some UITextField get the focus automatically when I enter controllerB. The code is very simple.
@implementation ControllerA
-(void)p_addClick:(id)sender {
ControllerB *controllerB = [[ControllerB alloc] init];
[self.navigationController pushViewController:controllerB animated:YES];
}
@end
@implementation ControllerB
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor grayColor];
_editorView = [[UITextField alloc] init];
_editorView.placeholder = @"test";
_editorView.clearButtonMode = UITextFieldViewModeWhileEditing;
_editorView.frame = CGRectMake(200, 200, 100, 100);
[_editorView becomeFirstResponder]; /* This is the point code */
[self.view addSubview:_editorView];
}
@end
If I code like this, then controllerB will first come out a little from the right of the screen, then go back, and finally show completely. It seems that the screen is shaking a little.
I test on some OS and found that only 16.0 and above models will behave like this, 15.5 and below is very smooth.
I think this seems to be a system bug, but don't know how to fix it.
I try to call becomeFirstResponder in the method of viewDidAppear in controllerB, then everything is OK. But there's many cases like this. Changing every controller seems not elegant enough.
