Question

我需要调整一条消息栏＆＃39;当键盘显示并且在使用iPad模态视图控制器时遇到问题。消息栏＆＃39;应该在键盘显示时坐在键盘顶部，然后在键盘隐藏时位于模态的底部（一个消息应用程序样式）。

问题是我需要根据Modal的坐标系获得键盘框架的最高点。我发现这个答案在理论上似乎是正确的，但不起作用（How can I find portion of my view which isn't covered by the keyboard (UIModalPresenationStyleFormSheet)?）：

FYI当显示键盘时，主窗口中的键盘框架（即＆＃39; keyboardFrame＆＃39;）=（ - 84.0,526.0,768.0,264.0）。翻译为模态视图控制器坐标系时的键盘框架（即＆＃39; newSize＆＃39;）=（-168.0,292.0,768.0,264.0）*

// Convert the keyboard rect into the view controller's coordinate system
// The fromView: nil means keyboardRect is in the main window's coordinate system
let newSize = self.view.convertRect(keyboardFrame, fromView: nil)

// And then this is the part that gets covered!
let keyboardCoveredHeight = self.view.bounds.height - newSize.origin.y
self.messageToolbar.bottomConstraint.constant = -keyboardCoveredHeight

enter image description here

Answer 1

我认为你遇到了两个问题之一（可能两个）：

在iOS 8中，您必须从屏幕的坐标空间转换键盘的矩形
在iPad上，当显示键盘时，工作表视图有时会向上移动一点，在显示键盘后发生，因此您需要再次计算的结果在viewWillLayoutSubviews

此处a sample project that does what you want。

对于后人来说，这是有趣的源代码：

class TypingViewController: UIViewController { var keyboardHoverView: UIView! // your keyboard toolbar or whatever var lastKeyboardFrame : CGRect! // whenever you get a frame update, store it here override func viewDidLoad() { super.viewDidLoad() createKeyboardHoverView() observeKeyboard() } func createKeyboardHoverView() { // make your keyboard toolbar keyboardHoverView = view } func observeKeyboard() { NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil) NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil) } func keyboardWillShow(notification : NSNotification) { let dict = notification.userInfo! let frameValue = dict[UIKeyboardFrameEndUserInfoKey] as! NSValue lastKeyboardFrame = frameValue.CGRectValue() moveKeyboardView() } func keyboardWillHide(notification : NSNotification) { moveKeyboardView() } override func viewWillLayoutSubviews() { // this moves the view again, in case the modal view has shifted up moveKeyboardView() } func moveKeyboardView() { if lastKeyboardFrame != nil { // this conversion is used in iOS 8 and differs from most online tutorials let frameInThisView = self.view.convertRect(lastKeyboardFrame, fromCoordinateSpace: view.window!.screen.coordinateSpace) var newRect = keyboardHoverView.frame newRect.origin.y = frameInThisView.origin.y - CGRectGetHeight(newRect) keyboardHoverView.frame = newRect println("Setting rect: \(newRect)") } } }

Answer 2

我最终使用熟悉的类别在iPad模式视图中获得正确的键盘框架：

- (CGFloat)heightCoveredByKeyboardOfSize:(CGSize)keyboardSize
{
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
CGRect frameInWindow = [self convertRect:self.bounds toView:nil];
CGRect windowBounds = self.window.bounds;

CGFloat keyboardTop;
CGFloat heightCoveredByKeyboard;

//Determine height of the view covered by the keyboard relative to current rotation

switch (orientation)
{
    case UIInterfaceOrientationLandscapeLeft:
    case UIInterfaceOrientationLandscapeRight:
        keyboardTop = windowBounds.size.height - keyboardSize.height;
        heightCoveredByKeyboard = windowBounds.size.height - frameInWindow.origin.y - keyboardTop;
        break;
    case UIInterfaceOrientationPortraitUpsideDown:
    default:
        keyboardTop = windowBounds.size.height - keyboardSize.height;
        heightCoveredByKeyboard = CGRectGetMaxY(frameInWindow) - keyboardTop;
        break;
}

return MAX(0.0f,heightCoveredByKeyboard);
}

以及DAKeyboardControl（用于平移）：

    // Use [unowned self] in closure for weak reference
    self.view.addKeyboardPanningWithFrameBasedActionHandler(nil, constraintBasedActionHandler: { [unowned self] (keyboardFrameInView, opening, closing) -> Void in
        if opening
        {
            if UIDevice.isIpad()
            {
                // iPad requires a different method due to use of modal view
                self.messageToolbar.bottomConstraint.constant = -self.view.heightCoveredByKeyboardOfSize(keyboardFrameInView.size)
            }
            else
            {
                self.messageToolbar.bottomConstraint.constant = -keyboardFrameInView.size.height
            }
        }

        if closing
        {
            self.messageToolbar.bottomConstraint.constant = 0
        }

        self.view.updateConstraintsIfNeeded()
        self.view.layoutIfNeeded()
    })

Answer 3

可以在keyboardDidShowNotification 上以这种方式计算精确重叠

let parentRelativeFrame = view.convert(view.frame, to: nil)
let viewBottomVerticalOffset = parentRelativeFrame.origin.y + parentRelativeFrame.height
let overlap = viewBottomVerticalOffset - keyboardFrame.origin.y

iOS：在iPad模式视图中获得键盘点的顶部？

3 个答案: