切换到另一个视图时隐藏键盘

Question

我在视图上有一些 UITextField，当点击它时会弹出键盘。还有一个按钮也可以导航到另一个视图。当我在键盘处于活动状态的情况下从该视图导航到第二个视图时，出现问题。当我从第二个视图导航回来时，键盘将单独出现。我该如何防止这种情况？

   -(IBAction) loginButton:(id) sender
    {
        [currentTextField resignFirstResponder];
        RequestPage *RequestPageview = [[RequestPage alloc] initWithNibName:nil bundle:nil];


        [UIView beginAnimations:@"flipping view" context:nil];
        [UIView setAnimationDuration:1];
        [UIView setAnimationCurve:UIViewAnimationCurveLinear];
        [UIView setAnimationTransition:UIViewAnimationTransitionCurlUp
                               forView:self.view.superview
                                 cache:YES];

        [UIView commitAnimations];
        [self presentModalViewController:RequestPageview animated:YES];
        //ß[self.view addSubview:RequestPageview.view];
    }
//---when the keyboard appears---
-(void) keyboardDidShow:(NSNotification *) notification {
    if (keyboardIsShown) return;

    NSDictionary* info = [notification userInfo];

    //---obtain the size of the keyboard---
    NSValue *aValue =
    [info objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect =
    [self.view convertRect:[aValue CGRectValue] fromView:nil];


    //---resize the scroll view (with keyboard)---
    CGRect viewFrame = [scrollview frame];
    NSLog(@"%f", viewFrame.size.height);
    viewFrame.size.height -= keyboardRect.size.height;
    scrollview.frame = viewFrame;
    NSLog(@"%f", keyboardRect.size.height);
    NSLog(@"%f", viewFrame.size.height);
    //---scroll to the current text field---
    CGRect textFieldRect = [currentTextField frame];
    [scrollview scrollRectToVisible:textFieldRect animated:YES];
    keyboardIsShown = YES;
        NSLog(@"Login Keyboard appear");
}

//---when the keyboard disappears---
-(void) keyboardDidHide:(NSNotification *) notification {
    NSDictionary* info = [notification userInfo];

    //---obtain the size of the keyboard---
    NSValue* aValue =
    [info objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect =
    [self.view convertRect:[aValue CGRectValue] fromView:nil];


    //---resize the scroll view back to the original size
    // (without keyboard)---
    CGRect viewFrame = [scrollview frame];
    viewFrame.size.height += keyboardRect.size.height;
    scrollview.frame = viewFrame;

    keyboardIsShown = NO;
        NSLog(@"Login Keyboard disappear");
}


2011-05-27 16:57:20.628 LoginPage[322:207] Login view appear // loaded the app
2011-05-27 16:57:32.220 LoginPage[322:207] Login Keyboard appear // tap on textfield
2011-05-27 16:57:35.665 LoginPage[322:207] Request view appeared // navigate to second view with keyboard shown
2011-05-27 16:57:35.667 LoginPage[322:207] Login view disappear
2011-05-27 16:57:35.978 LoginPage[322:207] Request Keyboard disappear // weird? I should have hide the Login Keyboard instead
2011-05-27 16:57:39.738 LoginPage[322:207] Login view appear // navigate back
2011-05-27 16:57:39.740 LoginPage[322:207] Request view disappeared 

Answer 1

如果您想在点击按钮时隐藏键盘，并且您有多个文本字段，那么您可以使用此代码...

[self.view endEditing:YES];

点击视图中的任何位置，键盘将会消失...

享受吧！...

Answer 2

在 loginButton 方法中，对正在编辑的文本字段调用 resignFirstResponder。当用户导航回该视图控制器时，键盘将不再存在。您需要稍微更改代码，以便可以引用文本字段。如果只有一个文本字段，则 IBOutlet 即可。对于多个字段，使您的视图控制器成为委托，并且您可以在用户开始编辑时保留对当前文本字段的引用。您还可以遍历视图的子视图，尽管这可能效率不高。