             if let strongSelf = self {
 
                 if strongSelf.messageToolbar.state == .MoreMessages {
-                    strongSelf.conversationCollectionView.contentOffset.y -= keyboardHeight - strongSelf.moreMessageTypesViewHeightConstraintConstant
-                    strongSelf.conversationCollectionView.contentInset.bottom = strongSelf.messageToolbar.frame.height + strongSelf.moreMessageTypesViewHeightConstraintConstant
-
-                    strongSelf.messageToolbarBottomConstraint.constant = strongSelf.moreMessageTypesViewHeightConstraintConstant
+                    strongSelf.conversationCollectionView.contentOffset.y -= keyboardHeight - strongSelf.moreMessageTypesViewDefaultHeight
+                    strongSelf.conversationCollectionView.contentInset.bottom = strongSelf.messageToolbar.frame.height + strongSelf.moreMessageTypesViewDefaultHeight
+
+                    strongSelf.messageToolbarBottomConstraint.constant = strongSelf.moreMessageTypesViewDefaultHeight
                     strongSelf.view.layoutIfNeeded()
 
                 } else {


                    // 注意第一次要减去已经有的高度偏移
                    if appearPostIndex == 0 {
                        strongSelf.conversationCollectionView.contentOffset.y += keyboardHeightIncrement - strongSelf.moreMessageTypesViewHeightConstraintConstant
                    } else {
                        strongSelf.conversationCollectionView.contentOffset.y += keyboardHeightIncrement
                    }

                        if previousState != .BeginTextInput && previousState != .TextInputing {

                            UIView.animateWithDuration(0.2, delay: 0.0, options: .CurveEaseInOut, animations: { _ in
                                strongSelf.conversationCollectionView.contentOffset.y += strongSelf.moreMessageTypesViewDefaultHeight
                                strongSelf.conversationCollectionView.contentInset.bottom = strongSelf.messageToolbar.frame.height + strongSelf.moreMessageTypesViewDefaultHeight

                                strongSelf.messageToolbarBottomConstraint.constant = strongSelf.moreMessageTypesViewDefaultHeight
                                strongSelf.view.layoutIfNeeded()

                            }, completion: { finished in
