by Jason J. Martin (1 Submission)
Category: Custom Controls/Forms/Menus
Compatability: Visual Basic 3.0
Difficulty: Unknown Difficulty
Date Added: Wed 3rd February 2021
Rating: 
(7 Votes)
Ever wondered what the button_click event was for in a DBGrid? Well, this is it! You have to populate a listbox control and display that with the selection information. This will simulate a dropdown box within the dbgrid. This is an excelent way to input specific information into the dbgrid.
Code Returns
Nont
Side Effects
Lose the ability to use the down arrow key in the column with the button.
API DeclarationsGlobal Declarations within form:
Dim intColIdx As Integer 'This will contain the index for the current cell in the dbgrid
Dim blnListShow As Boolean 'is the list showing or not
Dim intKeyCode As Integer 'the last key pressed within the dbgrid
VBcodersCreate a form with a dbgrid(DBGrid1), and a listbox(List1). Populate the listbox with the choices you need the user to select from. Set the visible property on the listbox to false. Set the button property on one of the DBGrid columns to true. This example is using column 2. If you want to limit the input to the DBGrid to just the items in the listbox, set the enabled property to false, otherwise, users can type in their own data.
Private Sub DBGrid1_ButtonClick(ByVal ColIndex As Integer)
Dim intTop As Integer 'used for positioning the list box for display.
intColIdx = ColIndex 'this is the column of the dbgrid you are in
If blnListShow = False Then 'if the list is not showing then...
blnListShow = True
List1.Left = DBGrid1.Columns(ColIndex).Left + 250 'you may have to play
'with this a little to get it
'positioned just right.
intTop = DBGrid1.Top + (DBGrid1.RowHeight * (DBGrid1.Row + 2))
List1.Top = intTop 'position the list box just below the row you are in
List1.Width = DBGrid1.Columns(ColIndex).Width + 15 'setting the width of
'the listbox to display
'within the column
' width
List1.Visible = True 'show the listbox
List1.SetFocus
Else 'if the list is shown, hide it
blnListShow = False
List1.Visible = False
End If
End Sub
Private Sub DBGrid1_KeyDown(KeyCode As Integer, Shift As Integer)
'This is to display the list when the user presses the down arrow key.
'This makes it easier to make a selection during data entry. The user
'doesn't have to go to the mouse to click the button.
If DBGrid1.Col = 2 Then 'change the number here to your appropriate column
'that has the button, other wise you will display the
' listbox on the wrong column
If KeyCode = vbKeyDown Then
Call DBGrid1_ButtonClick(DBGrid1.Col)
End If
End If
End Sub
Private Sub Form_Click()
'hide the listbox if the user clicks elsewhere
List1.Visible = False 'hide the list
End Sub
Private Sub Form_Load()
blnListShow = False 'initialize the variable
End Sub
Private Sub Form_Resize()
'hide the list if they resize the form
List1.Visible = False 'hide the list
End Sub
Private Sub List1_Click()
'insert the selected list item into the dbgrid, and hide the listbox
If intKeyCode <> vbKeyUp And intKeyCode <> vbKeyDown Then
DBGrid1.Columns(intColIdx).Text = List1.Text 'set the value of the dbgrid
List1.Visible = False 'hide the list
End If
End Sub
Private Sub List1_KeyDown(KeyCode As Integer, Shift As Integer)
'handle the keyboard events
intKeyCode = KeyCode
If intKeyCode = vbKeyReturn Then
DBGrid1.Columns(intColIdx).Text = List1.Text 'set the value of the dbgrid
List1.Visible = False 'hide the list
Else
If intKeyCode = vbKeyEscape Then
List1.Visible = False
End If
End If
End Sub
Private Sub List1_LostFocus()
'hide the list if you lose focus
blnListShow = False
List1.Visible = False
End Sub