void SetUpToolbar()
        {
            toolbar = new UIToolbar {
                TranslatesAutoresizingMaskIntoConstraints = false
            };
            chatInputView = new ChatInputView {
                TranslatesAutoresizingMaskIntoConstraints = false
            };

            View.AddSubview(toolbar);

            var pinLeft = NSLayoutConstraint.Create(toolbar, NSLayoutAttribute.Leading, NSLayoutRelation.Equal, View, NSLayoutAttribute.Leading, 1, 0);

            View.AddConstraint(pinLeft);

            var pinRight = NSLayoutConstraint.Create(toolbar, NSLayoutAttribute.Trailing, NSLayoutRelation.Equal, View, NSLayoutAttribute.Trailing, 1, 0);

            View.AddConstraint(pinRight);

            toolbarBottomConstraint = NSLayoutConstraint.Create(View, NSLayoutAttribute.Bottom, NSLayoutRelation.Equal, toolbar, NSLayoutAttribute.Bottom, 1, 0);
            View.AddConstraint(toolbarBottomConstraint);

            toolbarHeightConstraint = NSLayoutConstraint.Create(toolbar, NSLayoutAttribute.Height, NSLayoutRelation.Equal, null, NSLayoutAttribute.NoAttribute, 0, 44);
            View.AddConstraint(toolbarHeightConstraint);

            toolbar.AddSubview(chatInputView);

            var c1 = NSLayoutConstraint.FromVisualFormat("H:|[chat_container_view]|",
                                                         NSLayoutFormatOptions.DirectionLeadingToTrailing,
                                                         "chat_container_view", chatInputView
                                                         );
            var c2 = NSLayoutConstraint.FromVisualFormat("V:|[chat_container_view]|",
                                                         NSLayoutFormatOptions.DirectionLeadingToTrailing,
                                                         "chat_container_view", chatInputView
                                                         );

            toolbar.AddConstraints(c1);
            toolbar.AddConstraints(c2);
        }
		void SetUpToolbar ()
		{
			toolbar = new UIToolbar {
				TranslatesAutoresizingMaskIntoConstraints = false
			};
			chatInputView = new ChatInputView {
				TranslatesAutoresizingMaskIntoConstraints = false
			};

			View.AddSubview (toolbar);

			var pinLeft = NSLayoutConstraint.Create (toolbar, NSLayoutAttribute.Leading, NSLayoutRelation.Equal, View, NSLayoutAttribute.Leading, 1, 0);
			View.AddConstraint (pinLeft);

			var pinRight = NSLayoutConstraint.Create (toolbar, NSLayoutAttribute.Trailing, NSLayoutRelation.Equal, View, NSLayoutAttribute.Trailing, 1, 0);
			View.AddConstraint (pinRight);

			toolbarBottomConstraint = NSLayoutConstraint.Create (View, NSLayoutAttribute.Bottom, NSLayoutRelation.Equal, toolbar, NSLayoutAttribute.Bottom, 1, 0);
			View.AddConstraint (toolbarBottomConstraint);

			toolbarHeightConstraint = NSLayoutConstraint.Create (toolbar, NSLayoutAttribute.Height, NSLayoutRelation.Equal, null, NSLayoutAttribute.NoAttribute, 0, 44);
			View.AddConstraint (toolbarHeightConstraint);

			toolbar.AddSubview (chatInputView);

			var c1 = NSLayoutConstraint.FromVisualFormat ("H:|[chat_container_view]|",
				NSLayoutFormatOptions.DirectionLeadingToTrailing,
				"chat_container_view", chatInputView
			);
			var c2 = NSLayoutConstraint.FromVisualFormat ("V:|[chat_container_view]|",
				NSLayoutFormatOptions.DirectionLeadingToTrailing,
				"chat_container_view", chatInputView
			);
			toolbar.AddConstraints (c1);
			toolbar.AddConstraints (c2);
		}