UserForm to add from a selected cell from a TextBox value-CodePudding

I am trying to have a UserForm GUI so that we can add and subtract from inventory, I have got it so that I can select a worksheet and a row, but I am having trouble adding and subtracting part. Pretty new to VBA and I am not sure how to call that variable and modify it. Any help would be great!! Here is my code in the UserForm:

Option Explicit
Private Sub BTNadd_Click()
    
    
End Sub

Private Sub BTNDone_Click()
    'This will save and close the GUI'
    ThisWorkbook.Save
    StgRmGUI.Hide
End Sub

Private Sub BTNrmv_Click()

End Sub

Private Sub ItmNmSlct_Change()
    Dim actItm As String
    
End Sub

Private Sub ItmTypSlct_Change()
    'This allows ItmTypSlct to show available wrkshts then will make item show in Item Name box'
    With Worksheets(ItmTypSlct.Value)
    ItmNmSlct.RowSource = Range(.Cells(2, 1), .Cells(Rows.Count, 1).End(xlUp)).Address(, , , True)
End With
    
End Sub

Private Sub NumBox_Change()
    Dim NewVal As Integer

    NewVal = Val(NumBox.Text)
    If NewVal >= SpBtnARNum.Min And _
        NewVal <= SpBtnARNum.Max Then _
        SpBtnARNum.Value = NewVal
End Sub

Private Sub SpBtnARNum_Change()
    NumBox.Text = SpBtnARNum.Value
End Sub

Private Sub UserForm_Click()

End Sub

Private Sub UserForm_Initialize()
Dim ws As Worksheet

    For Each ws In ActiveWorkbook.Worksheets
        If ws.Visible = xlSheetVisible Then
            ItmTypSlct.AddItem ws.Name
        End If
    Next ws
    
End Sub

CodePudding user response：

An simple example of updating the column B value by the amount in NumBox

Private Sub BTNadd_Click()
     Dim r As Long, cell As Range
     With ItmNmSlct
          r = .ListIndex
          If r < 0 Then Exit Sub
          
          ' select quatity cell and increment value
          Set cell = Range(.RowSource).Cells(r   1, 2)
          cell.Value = cell.Value   NumBox.Value
     End With
End Sub