问题
With the latest iOS 8.3 release, our app starts to have a weird behavior.
After finishing textfield editing, the user can click the close button which brings up an UIAlertView. When the user clicks discard in the alertview, alertview and current view are dismissed. But somehow the keyboard shows up after the view is gone which is quite annoying to users.
After some debugging, it seems that the keyboard is shown for the last textfield that the user has accessed before closing the view. I tried various ways to endEditing for the current view in many places (before showing UIAlertView, after clicking a button in the UIAlertView; I even set the focus to another UI element of the view). It didn't solve the problem.
But for this particular issue, I'm not sure if it's a common issue or something we need to fix. Everything works perfectly before iOS 8.3.
We understand that UIAlertView is deprecated for iOS 8. We're starting to migrate to UIAlertController. But if there's any workaround, we'd love to hear.
Here's some code snippet.
- (IBAction)closeTapped:(UIButton *)sender
{
// try to resign first responder
// [self.tfName resignFirstResponder];
// [self.tfPosition resignFirstResponder];
[self.view endEditing:YES];
if(self.orderDetails.isOpen && self.orderItemChanged)
{
UIAlertView* saveAlert = [[UIAlertView alloc] initWithTitle:@"Unsaved Changes"
message:@"Your changes have not been saved. Discard changes?"
delegate:self
cancelButtonTitle:@"Cancel"
otherButtonTitles:@"Save", @"Discard", nil];
[saveAlert show];
}
else
{
[self close];
}
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
switch(buttonIndex)
{
case 1: // Save
{
[self save];
break;
}
case 2: // Discard
{
[self close];
break;
}
}
}
- (void)close
{
[self.delegate dismissEditOrderItemVC];
}
回答1:
If your deployment target is iOS 8+, try UIAlertController.
Here's a quick fix for UIAlertView: delay the invocation of showing the alert view when your text field or text view resigns first responder.
[self performSelector:@selector(showAlertView) withObject:nil afterDelay:0.6];
回答2:
If anyone struggles with this, I hope this will help:
if (NSClassFromString(@"UIAlertController")) {
UIAlertController* alert = ...
}
else {
UIAlertView* alert = ...
}
回答3:
you need to change alert for ios 8.3
first put this in your view
#define IS_IOS8 [[UIDevice currentDevice].systemVersion floatValue] >= 8.0
then
if (IS_IOS8) {
UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"Unsaved Changes" message:@"Your changes have not been saved. Discard changes?" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *saveAction = [UIAlertAction
actionWithTitle:@"Save"
style:UIAlertActionStyleCancel
handler:^(UIAlertAction *action)
{
[self save];
}];
UIAlertAction *cancelAction = [UIAlertAction
actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:^(UIAlertAction *action)
{
[alertVC dismissViewControllerAnimated:YES completion:nil];
}];
UIAlertAction *discardAction = [UIAlertAction
actionWithTitle:@"Discard"
style:UIAlertActionStyleCancel
handler:^(UIAlertAction *action)
{
[alertVC dismissViewControllerAnimated:YES completion:nil];
}];
[alertVC addAction:saveAction];
[alertVC addAction:cancelAction];
[alertVC addAction:discardAction];
[self.view.window.rootViewController presentViewController:alertVC animated:YES completion:nil];
this will help you as it helps me in same problem. above code is compatible with both ios 7 & 8
回答4:
I too, had a keyboard popping up (with the cursor in the last-used textView) after closing a UIAlertController and here is a very simple fix:
Immediately before building and presenting the UIAlertController,
Using [_activeTextView resignFirstResponder]; the keyboard will reappear. Using [self.view endEditing:YES]; the keyboard will NOT reappear.
I hope this helps you.
回答5:
Try using the below code. It works fine for iOS 8 and below version
if (IS_OS_8_OR_LATER) {
UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:title message:msg preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *cancelAction = [UIAlertAction
actionWithTitle:@"OK"
style:UIAlertActionStyleCancel
handler:^(UIAlertAction *action)
{
}];
[alertVC addAction:cancelAction];
[[[[[UIApplication sharedApplication] windows] objectAtIndex:0] rootViewController] presentViewController:alertVC animated:YES completion:^{
}];
}
else{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title message:msg delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
[alert show];
}
}
回答6:
If a text field is the first responder, it will automatically pop up the keyboard when the alert is dismissed. Ensure the first responder is properly dismissed with:
[textField resignFirstResponder]
Remember: in a table or scroll view, sometimes the field must be visible on the screen to properly dismiss the responder.
If there are no first responders active, keyboard should not appear when alert is dismissed.
For the particular case in this question, I would recommend setting a delegate method to listen for the "done" button and resigning the first responder in the delegate callback.
Alternatively, when beginning editing, you can store a reference to the currently active text field, then in your "clickedButtonAtIndex" method you can resign the active text field if it is still active.
回答7:
I've noticed some weird behavior with textField keyboards and alertViews as well... Maybe make a bool called disableKeyboard and use it like this:
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
if (disableKeyBoard) {
disableKeyboard = NO;
return NO;
} else {
return YES;
}
}
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex {
disableKeyboard = YES;
}
This is just a workaround and doesn't address the core issue, whatever it is. For this method to work you need to set the alertView and textField delegate methods in your header.
来源：https://stackoverflow.com/questions/30129278/keyboard-pops-up-after-uialertview-is-dismissed-on-ios-8-3-for-ipad