iphone - ResignFirstResponder 不会关闭键盘 (iPhone)

Question

我在这个网站上搜索过，但找不到解决我现在面临的问题的方法。希望有人能帮忙。

我创建了一个 UIAlertView 来提示用户在 iPhone 应用程序中输入他们的姓名。

    UIAlertView *enterNameAlert = [[UIAlertView alloc] initWithTitle:@"Enter your name"
                                                             message:@"\n\n\n"
                                                            delegate:self
                                                   cancelButtonTitle:NSLocalizedString(@"Cancel", nil)
                                                   otherButtonTitles:NSLocalizedString(@"OK", nil),nil];

    UITextField *enterNameField = [[UITextField alloc] initWithFrame:CGRectMake(16, 83, 252, 25)];
    enterNameField.keyboardAppearance = UIKeyboardAppearanceAlert;
    enterNameField.borderStyle = UITextBorderStyleRoundedRect;
    enterNameField.autocorrectionType = UITextAutocorrectionTypeNo;
    enterNameField.clearButtonMode = UITextFieldViewModeWhileEditing;
    enterNameField.returnKeyType = UIReturnKeyDone;
    enterNameField.delegate = self;
    [enterNameField becomeFirstResponder];
    [enterNameAlert addSubview:enterNameField];

    [enterNameAlert show];
    [enterNameAlert release];
    [enterNameField release];

我已将此 viewController 设置为符合头文件中的 UITextFieldDelegate，并实现了 textFieldShouldReturn: 尝试在用户点击“完成”时关闭键盘。

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    if ([textField isFirstResponder]) {
        [textField resignFirstResponder];
        NSLog(@"text field was first responder");
    } else {
        [textField becomeFirstResponder];
        [textField resignFirstResponder];
        NSLog(@"text field was not first responder");
    }
    NSLog(@"textfieldshouldreturn");
    return YES;
}

在调试器中，当我点击“完成”按钮时，我确认此方法已成功调用，此时 textField 是第一个响应者。然而，键盘并没有消失，只是那个小clearButton消失了。很明显，textField 不再是第一响应者，因为当我再次单击“完成”按钮时，没有任何内容被调用。我只想使用“完成”按钮关闭键盘。有人可以提供解决方案吗？万分感谢。

Answer 1

首先，您需要在界面 header 中定义您的enterNameAlert。然后使用下面的代码。

- (void)viewDidLoad {    
    [super viewDidLoad];
    enterNameAlert = [[UIAlertView alloc] initWithTitle:@"Enter your name"
                                                             message:@"\n\n\n"
                                                            delegate:self
                                                   cancelButtonTitle:NSLocalizedString(@"Cancel", nil)
                                                   otherButtonTitles:NSLocalizedString(@"OK", nil),nil];

    UITextField *enterNameField = [[UITextField alloc] initWithFrame:CGRectMake(16, 83, 252, 25)];
    enterNameField.keyboardAppearance = UIKeyboardAppearanceAlert;
    enterNameField.borderStyle = UITextBorderStyleRoundedRect;
    enterNameField.autocorrectionType = UITextAutocorrectionTypeNo;
    enterNameField.clearButtonMode = UITextFieldViewModeWhileEditing;
    enterNameField.returnKeyType = UIReturnKeyDone;
    enterNameField.delegate = self;    
    [enterNameAlert addSubview:enterNameField];
    [enterNameField becomeFirstResponder];
    [enterNameAlert show];    
    [enterNameField release];
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    if ([textField isFirstResponder]) {
        [textField resignFirstResponder];
        [enterNameAlert dismissWithClickedButtonIndex:1 animated:YES];
        [enterNameAlert release];
        NSLog(@"text field was first responder");
    } else {
        [textField becomeFirstResponder];
        [textField resignFirstResponder];
        NSLog(@"text field was not first responder");
    }
    NSLog(@"textfieldshouldreturn");
    return YES;
}