Iphone iOS 8自定义键盘高度从纵向更改为横向，再从横向更改为纵向

我们可以在viewdidload中创建自定义键盘，如apple开发者网站所示

self.nextKeyboardButton = [UIButton buttonWithType:UIButtonTypeSystem];

[self.nextKeyboardButton setTitle:NSLocalizedString(@"Next Keyboard", @"Title for 'Next Keyboard' button") forState:UIControlStateNormal];
[self.nextKeyboardButton sizeToFit];
self.nextKeyboardButton.translatesAutoresizingMaskIntoConstraints = NO;

[self.nextKeyboardButton addTarget:self action:@selector(advanceToNextInputMode) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:self.nextKeyboardButton];

NSLayoutConstraint *nextKeyboardButtonLeftSideConstraint = [NSLayoutConstraint constraintWithItem:self.nextKeyboardButton attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeLeft multiplier:1.0 constant:0.0];
NSLayoutConstraint *nextKeyboardButtonBottomConstraint = [NSLayoutConstraint constraintWithItem:self.nextKeyboardButton attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeBottom multiplier:1.0 constant:0.0];
[self.view addConstraints:@[nextKeyboardButtonLeftSideConstraint, nextKeyboardButtonBottomConstraint]];

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然而，有一个问题。当我们以纵向方式运行该程序时，自定义键盘的高度约为220。然后我们转向风景。不到220。奇怪的是，当我回到纵向视图时，高度不再是220，而是与横向高度相同。它永远不会回到原来的高度。那么，有没有一种方法可以改变我们将添加子视图的视图高度？

这可能是苹果键盘约束问题的一个缺陷，当我在日志中看到这些消息时：

 Unable to simultaneously satisfy constraints.
        Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
    (
        "<NSLayoutConstraint:0xfd04d80 V:[_UIKBCompatInputView:0xf97a580(216)]>",
        "<NSLayoutConstraint:0xe325bf0 V:[_UIKBCompatInputView:0xf97a580(162)]>"
    )

    Will attempt to recover by breaking constraint 
    <NSLayoutConstraint:0xfd04d80 V:[_UIKBCompatInputView:0xf97a580(216)]>

    Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
    The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

无法同时满足约束。
可能下面列表中至少有一个约束是您不想要的。试着这样做：（1）看看每个约束，试着找出你不期望的约束；（2） 找到添加了不需要的约束的代码，然后修复它。（注意：如果您看到不理解的NSAutoresizingMaskLayoutConstraints，请参阅UIView属性TranslatesAutoResizingMaskToConstraints的文档）
(
"",
""
)
将尝试通过打破约束进行恢复
在UIViewAlertForUnsatifiableConstraints处创建一个符号断点，以便在调试器中捕获该断点。
中列出的UIView上UIConstraintBasedLayoutDebugging类别中的方法也可能会有所帮助。

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我已经为它提交了一个bug。

嘿，woof-你如何使用键盘分机登录？我无法使用键盘扩展成功地将日志打印到控制台更新到最新Xcode在设备上运行时应修复日志。有时它仍然损坏，您可以尝试在最新的Xcode上卸载appBeen，但没有成功。也许这只是键盘扩展（相对于其他扩展）苹果已经修复了它们的约束错误，如果你使用自动布局，并且约束有问题，这也会被打破。对我来说，它时不时地显示没有。如果没有出现此类错误，则当at VIEWD出现时，self.view中没有约束。