使用iOS SDK:

我有一个带UITextFields的UIView,可以启动键盘。我需要它能够:

启动键盘后,允许滚动UIScrollView的内容以查看其他文本字段自动“跳转”(通过向上滚动)或缩短

我知道我需要一个UIScrollView。我已经尝试将UIView的类更改为UIScrollView,但仍然无法上下滚动文本框。

我需要UIView和UIScrollView吗?一个在另一个里面吗?

要自动滚动到活动文本字段,需要执行哪些操作?

理想情况下,尽可能多的组件设置将在Interface Builder中完成。我只想编写需要的代码。

注意:我使用的UIView(或UIScrollView)是由一个选项卡(UITabBar)启动的,它需要正常工作。


我正在添加滚动条,只为键盘出现时使用。尽管不需要它,但我觉得它提供了一个更好的界面,例如,用户可以滚动和更改文本框。

当键盘上下移动时,我可以改变UIScrollView的框架大小。我只是在使用:

-(void)textFieldDidBeginEditing:(UITextField *)textField {
    //Keyboard becomes visible
    scrollView.frame = CGRectMake(scrollView.frame.origin.x,
                                  scrollView.frame.origin.y,
    scrollView.frame.size.width,
    scrollView.frame.size.height - 215 + 50);   // Resize
}

-(void)textFieldDidEndEditing:(UITextField *)textField {
    // Keyboard will hide
    scrollView.frame = CGRectMake(scrollView.frame.origin.x,
                                  scrollView.frame.origin.y,
                                  scrollView.frame.size.width,
                                  scrollView.frame.size.height + 215 - 50); // Resize
}

然而,这不会自动“向上移动”或将可见区域中的下部文本字段居中,这是我真正想要的。


当前回答

这是使用Swift的解决方案。

import UIKit

class ExampleViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet var scrollView: UIScrollView!

    @IBOutlet var textField1: UITextField!
    @IBOutlet var textField2: UITextField!
    @IBOutlet var textField3: UITextField!
    @IBOutlet var textField4: UITextField!
    @IBOutlet var textField5: UITextField!

    var activeTextField: UITextField!

    // MARK: - View
    override func viewDidLoad() {
        super.viewDidLoad()
        self.textField1.delegate = self
        self.textField2.delegate = self
        self.textField3.delegate = self
        self.textField4.delegate = self
        self.textField5.delegate = self
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        self.registerForKeyboardNotifications()
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        self.unregisterFromKeyboardNotifications()
    }

    // MARK: - Keyboard

    // Call this method somewhere in your view controller setup code.
    func registerForKeyboardNotifications() {
        let center:  NSNotificationCenter = NSNotificationCenter.defaultCenter()
        center.addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
        center.addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
    }

    func unregisterFromKeyboardNotifications () {
        let center:  NSNotificationCenter = NSNotificationCenter.defaultCenter()
        center.removeObserver(self, name: UIKeyboardDidShowNotification, object: nil)
        center.removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }

    // Called when the UIKeyboardDidShowNotification is sent.
    func keyboardWasShown (notification: NSNotification) {
        let info : NSDictionary = notification.userInfo!
        let kbSize = (info.objectForKey(UIKeyboardFrameBeginUserInfoKey)?.CGRectValue() as CGRect!).size

        let contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
        scrollView.contentInset = contentInsets;
        scrollView.scrollIndicatorInsets = contentInsets;

        // If active text field is hidden by keyboard, scroll it so it's visible
        // Your app might not need or want this behavior.
        var aRect = self.view.frame
        aRect.size.height -= kbSize.height;
        if (!CGRectContainsPoint(aRect, self.activeTextField.frame.origin) ) {
            self.scrollView.scrollRectToVisible(self.activeTextField.frame, animated: true)
        }
    }

    // Called when the UIKeyboardWillHideNotification is sent
    func keyboardWillBeHidden (notification: NSNotification) {
        let contentInsets = UIEdgeInsetsZero;
        scrollView.contentInset = contentInsets;
        scrollView.scrollIndicatorInsets = contentInsets;
    }

    // MARK: -  Text Field

    func textFieldDidBeginEditing(textField: UITextField) {
        self.activeTextField = textField
    }

    func textFieldDidEndEditing(textField: UITextField) {
        self.activeTextField = nil
    }

}

其他回答

当UITextField位于UITableViewCell中时,应自动设置滚动。

如果不是,可能是因为表视图的代码/设置不正确。

例如,当我重新加载长表时,底部有一个UITextField,如下所示:,

-(void) viewWillAppear:(BOOL)animated
{
   [self.tableview reloadData];
}

然后,当我在文本字段内单击时,底部的文本字段被键盘遮挡。

为了解决这个问题,我必须这样做-

-(void) viewWillAppear:(BOOL)animated
{
    //add the following line to fix issue
    [super viewWillAppear:animated];
    [self.tableview reloadData];
}

要恢复到原始视图状态,请添加:

-(void)textFieldDidEndEditing:(UITextField *)sender

{
    //move the main view, so that the keyboard does not hide it.
    if  (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

找到最简单的解决方案

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    [self animateTextField: textField up: YES];
}


- (void)textFieldDidEndEditing:(UITextField *)textField
{
    [self animateTextField: textField up: NO];
}

- (void) animateTextField: (UITextField*) textField up: (BOOL) up
{
    const int movementDistance = 80; // tweak as needed
    const float movementDuration = 0.3f; // tweak as needed

    int movement = (up ? -movementDistance : movementDistance);

    [UIView beginAnimations: @"anim" context: nil];
    [UIView setAnimationBeginsFromCurrentState: YES];
    [UIView setAnimationDuration: movementDuration];
    self.view.frame = CGRectOffset(self.view.frame, 0, movement);
    [UIView commitAnimations];
}

简单的解决方案和最新的动画api。将origin.y更改215,您可以将其自定义为适合您的值。

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    if (self.view.frame.origin.y >= 0) {

        [UIView animateWithDuration:0.5 animations:^{
           self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y-215, self.view.frame.size.width, self.view.frame.size.height);
       }];
   }
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    if (self.view.frame.origin.y < 0) {
        [UIView animateWithDuration:0.5 animations:^{
           self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y+215, self.view.frame.size.width, self.view.frame.size.height);
        }];

    }
}

一个适用于许多UITextFields的小补丁:

#pragma mark UIKeyboard handling

#define kMin 150

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if (currTextField) {
        [currTextField release];
    }
    currTextField = [sender retain];
    // Move the main view, so that the keyboard does not hide it.
    if (self.view.frame.origin.y + currTextField.frame.origin. y >= kMin) {
        [self setViewMovedUp:YES];
    }
}


// Method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMovedUp:(BOOL)movedUp
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3]; // If you want to slide up the view

    CGRect rect = self.view.frame;
    if (movedUp)
    {
        // 1. move the view's origin up so that the text field that will be hidden come above the keyboard
        // 2. increase the size of the view so that the area behind the keyboard is covered up.
        rect.origin.y = kMin - currTextField.frame.origin.y ;
    }
    else
    {
        // Revert back to the normal state.
        rect.origin.y = 0;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)keyboardWillShow:(NSNotification *)notif
{
    // Keyboard will be shown now. Depending on which textfield is active, move up or move down the view appropriately

    if ([currTextField isFirstResponder] && currTextField.frame.origin.y + self.view.frame.origin.y >= kMin)
    {
        [self setViewMovedUp:YES];
    }
    else if (![currTextField isFirstResponder] && currTextField.frame.origin.y + self.view.frame.origin.y < kMin)
    {
        [self setViewMovedUp:NO];
    }
}


- (void)keyboardWillHide:(NSNotification *)notif
{
    // Keyboard will be shown now. Depending on which textfield is active, move up or move down the view appropriately
    if (self.view.frame.origin.y < 0 ) {
        [self setViewMovedUp:NO];
    }
}


- (void)viewWillAppear:(BOOL)animated
{
    // Register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification object:self.view.window];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification object:self.view.window];
}

- (void)viewWillDisappear:(BOOL)animated
{
    // Unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
}