webview上添加自定义view

思路：

1. 获取到键盘所在的window
2. 自定义view添加到window上

获取window的代码如下

- (UIWindow *)keyboardWindow{
    UIWindow *keyboardWindow = nil;
    for(UIWindow *window in [UIApplication sharedApplication].windows)
    {
        if([window isKindOfClass:NSClassFromString(@"UIRemoteKeyboardWindow")])
        {
            keyboardWindow = window;
        }
    }
    return keyboardWindow;
}

添加view代码如下

键盘出现：

- (void)keybordShowAnimalByKeyboardHeight:(float)keyboardHeight AndAnimalTime:(float)keyboardDuration{
    UIWindow *keyboardWindow = [self keyboardWindow];
    // 添加自定义view
    if (![keyboardWindow.subviews containsObject:self.toolBarView]) {
        [keyboardWindow addSubview:self.toolBarView];
        [keyboardWindow addSubview:self.keyBoardInputView];
    }
    // 键盘工具栏
    [self.keyBoardInputView mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.bottom.equalTo(keyboardWindow);
        make.left.right.equalTo(keyboardWindow);
        make.height.mas_equalTo(keyboardHeight);
    }];
    // 键盘覆盖层
    [self.toolBarView mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.bottom.equalTo(self.keyBoardInputView.mas_top);
        make.left.right.equalTo(keyboardWindow);
        make.height.mas_equalTo(TOOL_BAR_HEIGHT);
    }];
    // 更新约束
    [keyboardWindow layoutIfNeeded];
}

键盘隐藏：

- (void)keybordHiddenAnimalByKeyboardHeight:(float)keyboardHeight AndAnimalTime:(float)keyboardDuration{
    UIWindow *keyboardWindow = [self keyboardWindow];
    if (![keyboardWindow.subviews containsObject:self.toolBarView]) {
        [keyboardWindow addSubview:self.toolBarView];
        [keyboardWindow addSubview:self.keyBoardInputView];
    }
    // 修改为以前的约束（距下边距0）这么写的目的是为了动画效果
    [self.toolBarView mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(keyboardWindow.mas_bottom);
        make.left.right.equalTo(keyboardWindow);
        make.height.mas_equalTo(TOOL_BAR_HEIGHT);
    }];
    [self.keyBoardInputView mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.toolBarView.mas_bottom);
        make.left.right.equalTo(keyboardWindow);
        make.height.mas_equalTo(keyboardHeight);
    }];
    // 更新约束
    [keyboardWindow layoutIfNeeded];
}