当键盘出现时使视图可滚动答案

【问题标题】：Making the view scrollable when keyboard appears当键盘出现时使视图可滚动
【发布时间】：2011-09-02 14:32:51
【问题描述】：

在我的第一个视图上设法得到它，但在第二个视图上不起作用。

这是我在两个视图上所做的，只是在控制台中用于调试目的略有不同

-(void) viewWillAppear:(BOOL)animated {
    //---registers the notifications for keyboard---
    // to see if keyboard is shown / not shown
    [[NSNotificationCenter defaultCenter]
     addObserver: self
     selector:@selector(keyboardDidShow:)
     name:UIKeyboardDidShowNotification
     object:self.view.window];

    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(keyboardDidHide:)
     name:UIKeyboardDidHideNotification
     object:nil];
}

//---when the keyboard appears---
-(void) keyboardDidShow:(NSNotification *) notification {
    if (keyboardIsShown) return;
    NSLog(@"Keyboard is visible 1"); // debugger purpose "Keyboard is visible 2" on the second view.

    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;
}

//---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;
}

//---before the View window disappear---
-(void) viewWillDisappear:(BOOL)animated {
    //---removes the notifications for keyboard---
    [[NSNotificationCenter defaultCenter]
     removeObserver: self
     name:UIKeyboardWillShowNotification
     object:nil];

    [[NSNotificationCenter defaultCenter]
     removeObserver:self
     name:UIKeyboardWillHideNotification
     object:nil];
}

【问题讨论】：

您看到的错误行为是什么？
我尝试在调试器控制台中测试输出。我在我的 secondview 上删除了 NSLog。但是当键盘出现在两个视图中时，它会一直显示 3 行。
简单来说，当键盘出现在第二个视图时，输出NSLog(@"Keyboard is visible 1");而不是 NSLog(@"Keyboard is visible 2");
我认为这可能是我加载视图 2 的方式，因为当我导航到视图 2 时未执行 viewDidLoad 方法。以前使用 codeRegisters *registerview = [[Registers alloc] initWithNibName :nil 捆绑:nil]; [self presentModalViewController:registerview Animation:YES];
@Deepak 然后我改为使用 [self presentModalViewController:registerview animated:YES];反而。 view2 的 ViewDidLoad 已执行，并且启用了滚动，但出现了一些问题。当键盘出现在 view2 中时，keyboardDidShow 方法在 view1 和 view2 上都被触发。控制台输出如下“Keyboard is visible 1 & Keyboard is visible 2”

标签： xcode view keyboard scroll

【解决方案1】：

您正在注册 UIKeyboardDidShowNotification 和 UIKeyboardDidHideNotification 通知，然后取消注册 UIKeyboardWillShowNotification 和 UIKeyboardWillHideNotification 通知。这是你的错误。

【讨论】：

对不起，我是一个新手，我没有明白我应该做些什么来解决这个错误。你能指导我吗？谢谢你的帮助。真的很感激。哦，NVM，我明白了。非常感谢！