How to merge cells in datagridview?

[rookiebot]

Hi,

Is the following grid layout possible with DataGridView in VB.net? Kind of similiar to html table layout. I'm adding data cell by cell. However I'm not sure on how to get the layout for Group A & Group B Cells

-------------------------------------------------|
       | Item11      | Item12      | Item13      |
       |-----------------------------------------|
       | Item21      | Item22      | Item23      |
GroupA |-----------------------------------------|
       | Item31      | Item32      | Item33      |
       |-----------------------------------------|
       | Item41      | Item42      | Item43      |
-------------------------------------------------|
       | Item51      | Item52      | Item53      |
       |-----------------------------------------|
GroupB | Item61      | Item62      | Item63      |
       |-----------------------------------------|
       |Item71      | Item72      | Item73       |
-------------------------------------------------|

Any help appreciated ...

[rakesh_sharma23]

Suppose one want to merge Cell 2 and 3 in Row 0 of a Datagrid(dg_ESC) then type following code in Cell Painting event of the Datagrid


Private Sub dg_ESC_CellPainting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles dg_ESC.CellPainting

If e.RowIndex = 0 AndAlso (e.ColumnIndex = 2 Or e.ColumnIndex = 3) Then
Using gridBrush As Brush = New SolidBrush(Me.dg_ESC.GridColor), backColorBrush As Brush = New SolidBrush(e.CellStyle.BackColor)
Using gridLinePen As Pen = New Pen(gridBrush)
' Clear cell
e.Graphics.FillRectangle(backColorBrush, e.CellBounds)
'Bottom line drawing
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1)
'top line drawing
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Top, e.CellBounds.Right - 1, e.CellBounds.Top)
'Drawing Right line
If e.ColumnIndex = 3 Then
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top, e.CellBounds.Right - 1, e.CellBounds.Bottom)
End If
'Inserting text
If e.ColumnIndex = 3 Then
e.Graphics.DrawString(CType(e.Value, String), e.CellStyle.Font, Brushes.Black, e.CellBounds.X - (e.CellBounds.X / 4), e.CellBounds.Y + 5)
End If
e.Handled = True
End Using
End Using
End If

This solve's the problem...

Thanking

Rakesh Sharma,

Jodhpur INDIA

[MacShand]

Is it possible to either:

Assign a similar code to a button to merge user-selected cells;
code the cell painting so that if two cells appear next to each other have the same content, they automatically "merge" as highlighted above?

I'd be looking to merge across rows, eg, in the example below, BEFORE the code took action, row 1,2 and 3 of Column A all held the text ''DATA 123''

========================
COLUMN A | COLUMN B |
------------------------------
Row1.| |''col. b info''|
Row2.| DATA 123 |more info |
Row3.| |further info |

[kevininstructor]

Use the custom DataGridView here.

Here is a working example project here

[MacShand]

Hi Kevin - im coding in vb.net and am new at programming so am unable to convert ... any further suggestions? I've found some samples, eg...

Private Sub DataGridView1_CellPainting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles DataGridView1.CellPainting


        Dim y As Integer

        For y = 0 To DataGridView1.Rows.Count - 1

            If (e.ColumnIndex = 0 And e.RowIndex = y) Then

                If Not IsNumeric(DataGridView1(0, y).Value) Then   ' for instance i wanted to make something like band end merged with the next cell(s.t.h. like header band )

                    e.AdvancedBorderStyle.Right = DataGridViewAdvancedCellBorderStyle.Single

                End If

                e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.Single

            End If

           
            If (e.ColumnIndex = 1 And e.RowIndex = y) Then

                If y > 0 Then

                    If DataGridView1(1, y).Value = DataGridView1(1, y - 1).Value Then
                    Else

                        e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.Single

                    End If
                End If

            End If


        Next

    End Sub

This is fine, but ideally, I'd like the merged cells to look like cells that are merged in excel, ie, just one line of text, centred in the merged cells, rather than the same thing repeated in all rows...(hope that makes sense)

help is greatly appreciated

[kevininstructor]

Hi Kevin - im coding in vb.net and am new at programming so am unable to convert ... any further suggestions? I've found some samples, eg...

Private Sub DataGridView1_CellPainting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles DataGridView1.CellPainting


        Dim y As Integer

        For y = 0 To DataGridView1.Rows.Count - 1

            If (e.ColumnIndex = 0 And e.RowIndex = y) Then

                If Not IsNumeric(DataGridView1(0, y).Value) Then   ' for instance i wanted to make something like band end merged with the next cell(s.t.h. like header band )

                    e.AdvancedBorderStyle.Right = DataGridViewAdvancedCellBorderStyle.Single

                End If

                e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.Single

            End If

           
            If (e.ColumnIndex = 1 And e.RowIndex = y) Then

                If y > 0 Then

                    If DataGridView1(1, y).Value = DataGridView1(1, y - 1).Value Then
                    Else

                        e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.Single

                    End If
                End If

            End If


        Next

    End Sub

This is fine, but ideally, I'd like the merged cells to look like cells that are merged in excel, ie, just one line of text, centred in the merged cells, rather than the same thing repeated in all rows...(hope that makes sense)

help is greatly appreciated

Is there a reason for adding cells one by one? Have you considered creating a DataTable, adding rows to the DataTable then assign the DataTable to the DataGridView DataSource as this would make this a lot easier. Otherwise you are in for a great mess of code to contend with.

In the example below the rows added might simulate obtaining data from some source i.e. a text file etc.

Private Sub Demo()
    Dim MockedData As New DataTable()
    MockedData.Columns.AddRange(New DataColumn() _
        { _
            New DataColumn("Identifier", GetType(System.Int32)), _
            New DataColumn("ColumnA", GetType(System.String)), _
            New DataColumn("ColumnB", GetType(System.String)) _
        } _
    )

    MockedData.TableName = "Mocked"

    MockedData.Rows.Add(New Object() {1, "A", "Apples"})
    MockedData.Rows.Add(New Object() {1, "B", "Grapes"})
    MockedData.Rows.Add(New Object() {1, "C", "Pears"})
    MockedData.Rows.Add(New Object() {3, "D", "Cherries"})
    MockedData.Rows.Add(New Object() {3, "E", "Oranges"})
    MockedData.Rows.Add(New Object() {6, "F", "Prunes"})
    MockedData.Rows.Add(New Object() {6, "G", "Grapes"})
    MockedData.Rows.Add(New Object() {6, "H", "Oranges"})
    MockedData.Rows.Add(New Object() {6, "I", "Oranges"})

    DataGridView1.DataSource = MockedData
End Sub

I am not saying this is right for you since it sounds like you have taken a different path to load data but we need to be flexible and at least consider other options such as this.

[MacShand]

The way the form works at run time, is that the user inputs the data to the datagridview in defined columns, but the rows will be changed so pre-loaded data will unfortunately not work. I appreciate you thinking of alternatives, it's great to get help and advice.

Also, is the code you've suggested above for C# programming? I'm using Visual Basic 2010.

Cheers

[kevininstructor]

Private Sub DataGridView1_CellPainting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles DataGridView1.CellPainting


        Dim y As Integer

        For y = 0 To DataGridView1.Rows.Count - 1

            If (e.ColumnIndex = 0 And e.RowIndex = y) Then

                If Not IsNumeric(DataGridView1(0, y).Value) Then   ' for instance i wanted to make something like band end merged with the next cell(s.t.h. like header band )

                    e.AdvancedBorderStyle.Right = DataGridViewAdvancedCellBorderStyle.Single

                End If

                e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.Single

            End If

           
            If (e.ColumnIndex = 1 And e.RowIndex = y) Then

                If y > 0 Then

                    If DataGridView1(1, y).Value = DataGridView1(1, y - 1).Value Then
                    Else

                        e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.Single

                    End If
                End If

            End If


        Next

    End Sub

Here is a consideration in regards to having logic in cell paint, place the following into your form with any amount of rows, at least two columns. At run time traverse thru the cells and each time you move cell to cell the Paint event is called, does this raise any red flags to you? It should.

Private Sub DataGridView1_Paint( _
    ByVal sender As Object, _
    ByVal e As System.Windows.Forms.PaintEventArgs) _
    Handles DataGridView1.Paint

    Console.WriteLine(Now)
End Sub

[kevininstructor]

The way the form works at run time, is that the user inputs the data to the datagridview in defined columns, but the rows will be changed so pre-loaded data will unfortunately not work. I appreciate you thinking of alternatives, it's great to get help and advice.
Cheers

I do not have time to code an example but the custom DataGridView can work for your situation.

Basic steps:
1. Assign an empty DataTable as the DataSource of the DataGridView.
2. User inputs data, you add a new row to the DataTable
3. Refresh the DataSource of the DataGridView

Also, is the code you've suggested above for C# programming? I'm using Visual Basic 2010.

The link is in C Sharp but the code I supplied is VB.NET a conversion from the original code. Hence it works in VS2010 VB.NET