在 UITextField UIControlEventEditingDidBegin 上调用 UIAlertView 关闭键盘

Question

我注意到一些非常奇怪的行为。我想在选择 UITextField 时显示 UIAlertView：

[self.addressTextField addTarget:self action:@selector(addressTextFieldSelected) forControlEvents:UIControlEventEditingDidBegin];

正在调用的方法是：

- (void)addressTextFieldSelected {

    if (!geoPoint) {

        UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Text" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alertView show];

    }

}

触摸 textField 时，键盘确实开始向上滑动。但是，当 alertView 出现时，键盘消失了。选择 'OK' 并关闭 alertView 后，文本字段的键盘向上滑动。

编辑

在其他人的帮助下，我创建了这个解决方法，尽管我对键盘一开始就消失有点不满意。

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {

    if (textField.tag == 2) {

        if (!geoPoint && !justShowedGeoPointAlert) {

            showingGeoPointAlert = YES;

            UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Make sure to geotag this address." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
            [alertView show];

            return NO;

        } else {

            justShowedGeoPointAlert = NO;

        }

    }

    return YES;

}

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex {

    if (showingGeoPointAlert) {

        justShowedGeoPointAlert = YES;
        showingGeoPointAlert = NO;
        [self.addressTextField becomeFirstResponder];

    }

}

Answer 1

将 UIAlertView 的代码移至 - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField，如果 return NO 键盘将不会出现

Answer 2

实现以下 UITextField 的委托方法：

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField;

在此方法中显示警报视图，return在此方法中为否，将不显示键盘。

然后实现以下UIAlertView的委托方法：

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex;

在此方法中，显示键盘：

[self.addressTextField becomeFirstResponder];

Answer 3

尝试如下操作：

@interface ViewController () <UIAlertViewDelegate, UITextFieldDelegate>

@property (weak, nonatomic) IBOutlet UITextField *textField;
@property (weak, nonatomic) UITextField *selectedTextField;

@end

@implementation ViewController

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
    if (textField == self.selectedTextField) {
        self.selectedTextField = nil;
        return YES;
    }

    self.selectedTextField = textField;

    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Text" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alertView show];

    return NO;
}

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex {
    [self.selectedTextField becomeFirstResponder];
}

@end

在 UITextField UIControlEventEditingDidBegin 上调用 UIAlertView 关闭键盘

Calling UIAlertView on UITextField UIControlEventEditingDidBegin dismisses keyboard

objective-c

uitextfield

uialertview

ios