问题

近日在写代码时，有时候会写全局的弹出框，我一般是直接把view贴在keywindow上，我发现在keywindow上的视图中有输入框的时候，IQKeyboardManager无法自动将这个输入框弹起。

排查过程

要找这个问题还得看IQKeyboardManager源码，我发现IQKeyboardManager是根据相应者链拿到所属UIViewController，然后再做之后的操作，如果没找到，之后的操作都白搭，因为我的view是直接创建好加在了keywindow上，没有归于某个UIViewController，所以就会出现无效的问题。

查找解决办法

于是呼我去百度了一番，没找到解决方案。
我又找到了IQKeyboardManager的github，查看issue，发现果然有人更我有同样的困惑，并且开发者回复的是

This library don't support textFields that are directly added to a UIWindow, it must come throught UIViewController or one of it's subclass.

此库不支持直接添加到uiwindow的文本字段，它必须通过uiviewcontroller或其子类之一。

issue截图
WTF！开发者直接就说不适配加在keywindow上的输入框。

解决办法

万万没想到，最终我还是解决了这个问题。
我模仿IQKeyboardManager，自己实现了一个支持keywindow的KeyboardManager，思路是这样的：

创建一个单例。
重写+ (void)load;方法，模仿IQKeyboardManager的拖进项目就生效功能。
监听keyboard的弹出通知和UITextField的开始结束编辑通知。
[主要操作]在开始编辑时用响应者链查找UIViewController如果有的话不处理，正常的还是交给IQKeyboardManager处理吧，毕竟人家是专业的。每找到一个UIView就做记录，直到找到UIWindow，这时候我就记录了uiview之前响应者链中的最后一个view，然后在键盘弹起时如果键盘高度高于textfield就将这个找到的view向上提起一部分，我用的是CGAffineTransform做的移动，因为方便恢复，恢复的话只需要把view的transform设置为CGAffineTransformIdentity就可以复原了。

上代码

下面代码是整个manager的.m代码，只是实现了一个简单的UITextfield上提功能

#import "WZZKeyboardManager.h"

WZZKeyboardManager * wzzKeyboardManager;

@interface WZZKeyboardManager ()

@property (assign, nonatomic) CGRect keyboardFrame;
@property (weak, nonatomic) UITextField * nowTF;

@end

@implementation WZZKeyboardManager

+ (void)load {
    [self shareInstance];
}

+ (instancetype)shareInstance {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        wzzKeyboardManager = [[WZZKeyboardManager alloc] init];
        [wzzKeyboardManager setup];
    });
    return wzzKeyboardManager;
}

- (void)setup {
    [[NSNotificationCenter defaultCenter] addObserver:wzzKeyboardManager selector:@selector(KeyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:wzzKeyboardManager selector:@selector(KeyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:wzzKeyboardManager selector:@selector(TextFieldTextDidBeginEditing:) name:UITextFieldTextDidBeginEditingNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:wzzKeyboardManager selector:@selector(TextFieldTextDidEndEditing:) name:UITextFieldTextDidEndEditingNotification object:nil];
}

- (void)KeyboardWillShow:(NSNotification *)noti {
    NSValue * vv = noti.userInfo[UIKeyboardFrameEndUserInfoKey];
    self.keyboardFrame = [vv CGRectValue];
    UITextField * tf = self.nowTF;
    UIView * view = [self getViewOnWindow:tf];
    if (view) {
        CGRect fr = [tf.superview convertRect:tf.frame toView:[UIApplication sharedApplication].keyWindow];
        CGRect fr2 = [view.superview convertRect:view.frame toView:[UIApplication sharedApplication].keyWindow];
        CGFloat y = CGRectGetMaxY(fr);
        CGFloat y2 = self.keyboardFrame.origin.y;
        CGFloat y3 = y2-y-8;
        if (y3 < 0) {
            //tf提起
            [UIView animateWithDuration:0.25f animations:^{
                view.transform = CGAffineTransformMakeTranslation(fr2.origin.x, fr2.origin.y+y3);
            }];
        }
    }
}

- (void)KeyboardWillHide:(NSNotification *)noti {
//    NSLog(@"wzz%@", noti.userInfo);
}

- (void)TextFieldTextDidBeginEditing:(NSNotification *)noti {
    UITextField * tf = noti.object;
    self.nowTF = tf;
}

- (void)TextFieldTextDidEndEditing:(NSNotification *)noti {
    UITextField * tf = noti.object;
    UIView * view = [self getViewOnWindow:tf];
    if (view) {
        [UIView animateWithDuration:0.25f animations:^{
            view.transform = CGAffineTransformIdentity;
        }];
    }
}

- (UIView *)getViewOnWindow:(UIView *)view {
    UIResponder *nextResponder = view;
    
    while (![nextResponder isKindOfClass:[UIWindow class]]) {
nextResponder = [nextResponder nextResponder];

        if (!nextResponder) {
            return nil;
        }
        if ([nextResponder isKindOfClass:[UIViewController class]]) {
            return nil;
        }
        if (![nextResponder isKindOfClass:[UIWindow class]] && [nextResponder isKindOfClass:[UIView class]]) {
            view = (UIView *)nextResponder;
        }
    }
    
    return view;
}

@end