iOS8以后第三方键盘获取高度不对的问题

iOS8以后苹果可以安装第三方键盘，

通过断点我们会发现使用第三方键盘之后，

键盘将要弹出的方法：- (void)keyBoardWillShow:(NSNotification *)notification会执行三次，

三次的高度分别是:0:216:282。我们发现我们需要的是第三次的高度。

我们需要注册键盘隐藏和显示的通知：

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyBoardDidHide:) name:UIKeyboardWillHideNotification object:nil];

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];

#pragma mark–键盘显示事件

- (void)keyboardWillShow:(NSNotification *)notification {
    CGFloat curkeyBoardHeight = [[[notification userInfo] objectForKey:@"UIKeyboardBoundsUserInfoKey"] CGRectValue].size.height;
    CGRect begin = [[[notification userInfo] objectForKey:@"UIKeyboardFrameBeginUserInfoKey"] CGRectValue];
    CGRect end = [[[notification userInfo] objectForKey:@"UIKeyboardFrameEndUserInfoKey"] CGRectValue];
    
    // 第三方键盘回调三次问题，监听仅执行最后一次
    if(begin.size.height>0 && (begin.origin.y-end.origin.y>0)){
        
        CGFloat keyBoardHeight = curkeyBoardHeight;
        
        NSLog(@"第三次：%f",keyBoardHeight);
        [UIView  animateWithDuration:0.05 animations:^{
            self.bgView.hidden = NO;
            self.commentToolView.y = kScreenHeight - keyBoardHeight - 44;
            
        }];
    }
}

#pragma mark–键盘隐藏事件

-(void)keyBoardDidHide:(NSNotification *)notification{
    NSLog(@"键盘隐藏");
    self.bgView.hidden = YES;
    self.commentToolView.y = kScreenHeight;
}