Edit data in the msflexgrid cells in VB6.0

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Q)

I have a msflexgrid control. I want the user to input some data. But I when I click the cell, it won't put itself in edit mode. How do u edit these cells?

A)

I have no idea why Microsoft has not added direct editing to the FlexGrid Control; I guess it has been designed for read only, databinding. Anyway, I have posted the standard work around that I always use, it is a bit long, but it works great.

MSFlexGrid does not have a built-in cell editing capability, but it provides the hooks to make it easy for you to add that capability programmatically. The advantage of this approach is that you can tailor editing behavior to your taste. The basic technique involves smoke and mirrors: the editing occurs not in MSFlexGrid at all, but in a standard Textbox control that is positioned precisely over the cell being edited.

In this example, we will give the user two ways to get into the edit mode, either by double-clicking on a cell, or by simply starting to type in the current cell. The following two routines implement this:

Private Sub MSFlexGrid1_DblClick()
GridEdit Asc(" ")
End Sub

Private Sub MSFlexGrid1_KeyPress(KeyAscii As Integer)
GridEdit KeyAscii
End Sub

In each case we call a grid edit subroutine and pass it a keystroke. In the case of double-clicking, we pass the space character as a flag. The GridEdit routine initializes the edit box and moves it into position:

Sub GridEdit(KeyAscii As Integer)

'use correct font
Text1.FontName = MSFlexGrid1.FontName
Text1.FontSize = MSFlexGrid1.FontSize

Select Case KeyAscii
Case 0 To Asc(" ")
Text1 = MSFlexGrid1
Text1.SelStart = 1000
Case Else
Text1 = Chr(KeyAscii)
Text1.SelStart = 1
End Select
'position the edit box
Text1.Left = MSFlexGrid1.CellLeft + MSFlexGrid1.Left
Text1.Top = MSFlexGrid1.CellTop + MSFlexGrid1.Top
Text1.Width = MSFlexGrid1.CellWidth
Text1.Height = MSFlexGrid1.CellHeight
Text1.Visible = True
Text1.SetFocus
End Sub

For demonstration purposes, the Case statement in the GridEdit routine shows two different behaviors when entering the edit mode. In practice you would probably only use one of them, or a different one of your own creation. If the edit mode is entered by virtue of a double-click or a control key press, we copy the contents of the grid cell to the exit box and place the cursor at the end of the string. If the edit mode is entered by pressing a normal key, we ignore the original cell contents and insert the pressed key into the edit box. The positioning of the exit box could be done on one line with the Move method. Here we have used four lines so that it reads more easily in this article. Notice that MSFlexGrid conveniently gives us all the coordinate information we need.

Next, we need a couple of routines that handle housekeeping when the user moves to a different cell or moves focus back to the grid from another control. The LeaveCell event is also the place where you would put any data validation code that might be applicable.

Private Sub MSFlexGrid1_LeaveCell()
If Text1.Visible Then
MSFlexGrid1 = Text1
Text1.Visible = False
End If
End Sub

Private Sub MSFlexGrid1_GotFocus()
If Text1.Visible Then
MSFlexGrid1 = Text1
Text1.Visible = False
End If
End Sub

Next we place some navigation code in the KeyDown event of the edit box so that, for instance, the user can leave the edit mode by pressing ESC, and move to a different row by pressing an arrow key:

Private Sub Text1_KeyDown(KeyCode As Integer, Shift As Integer)
Select Case KeyCode
Case vbKeyEscape
Text1.Visible = False
MSFlexGrid1.SetFocus
Case vbKeyReturn
MSFlexGrid1.SetFocus
Case vbKeyDown
MSFlexGrid1.SetFocus
DoEvents
If MSFlexGrid1.Row < MSFlexGrid1.Rows - 1 Then
MSFlexGrid1.Row = MSFlexGrid1.Row + 1
End If
Case vbKeyUp
MSFlexGrid1.SetFocus
DoEvents
If MSFlexGrid1.Row > MSFlexGrid1.FixedRows Then
MSFlexGrid1.Row = MSFlexGrid1.Row - 1
End If
End Select
End Sub

Finally we need a line of code to suppress the Beep that occurs when ENTER is pressed in a Textbox:

Private Sub Text1_KeyPress(KeyAscii As Integer)
'noise suppression
If KeyAscii = vbKeyReturn Then KeyAscii = 0
End Sub


In order for the edit box to merge seamlessly into the grid, you need to set several Textbox properties at design-time: set Appearance = 0 (flat), and BorderStyle = 0 (none). Also set Visible = False so that the edit box is not initially visible. To really fine-tune this code, the edit box needs a slight additional offset to the southeast (with a corresponding reduction in size) so that the text in it lines up exactly with the text in the cell beneath. You would probably also want to write some code behind the scroll event of the grid since clicking on the grid's scroll bar will not cause the edit box to loose focus.

Note that this technique is not limited to using a Textbox as your edit box. You could modify the sample code to use a ComboBox, a CheckBox, or even a calendar control for editing, based on the column being edited.

MSFlexGrid is a very flexible control indeed, and this article just touches on some of the things you can do with it. As you gain familiarity with it, it will become a more regular part of your toolbox. Cell merging and pivoting are two more unique features of the MSFlexGrid that give it tremendous power and bear investigation. Comments pls

Credits: Shreejith G