Select All Cells in a DataGridView Column or Row on Header Click

Question

I have a DataGridView with SelectionMode = "CellSelect".  I do this because I want the user to be able to click the Column Header and drag the column to a different DisplayIndex.  They move the column by clicking and holding down the left mouse button, then moving the column.  I also want the user to be able to click the column header and all the cells in the column would be selected.  But if I change the SelectionMode property to "FullColumnSelect" or "ColumnHeaderSelect" the user can no longer move the column.

In the code below, I can select all the cells in the DataGridView just fine, but I can't select all cells in a particular Column or Row.  Any ideas?

    Private Sub DGV_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles dgvPending.MouseDown, dgvCurrent.MouseDown, dgvCompleted.MouseDown

        If e.Button = Windows.Forms.MouseButtons.Left Then

            Dim dgv As DataGridView = CType(sender, DataGridView)
            Dim ht As DataGridView.HitTestInfo = dgv.HitTest(e.X, e.Y)

            dgv.SuspendLayout()

            Select Case ht.Type

                ' select all cells
                Case Is = DataGridViewHitTestType.TopLeftHeader
                    dgv.SelectAll()

                    'select the entire column
                Case Is = DataGridViewHitTestType.ColumnHeader
                    dgv.Columns(ht.ColumnIndex).Selected = True
                    For i As Integer = 0 To dgv.Rows.Count - 1
                        dgv.Item(i, ht.ColumnIndex).Selected = True
                    Next

                    'select all cells in the row entire row
                Case Is = DataGridViewHitTestType.RowHeader
                    dgv.Rows(ht.RowIndex).Selected = True
                    For i As Integer = 0 To dgv.Columns.Count - 1
                        dgv.Item(ht.RowIndex, i).Selected = True
                    Next
            End Select
            dgv.ResumeLayout()
        End If

        ' call the appropriate context menu
        If e.Button = Windows.Forms.MouseButtons.Right Then

            Dim dgv As DataGridView = CType(sender, DataGridView)

            Select Case dgv.Name
                Case Is = "dgvPending" : Me.penDGVSettings.ShowContextMenu(sender, e, Me.flpPending)
                Case Is = "dgvCurrent" : Me.curDGVSettings.ShowContextMenu(sender, e, Me.flpCurrent)
                Case Is = "dgvCompleted" : Me.comDGVSettings.ShowContextMenu(sender, e, Me.flpCompleted)
            End Select
        End If

    End Sub

Thanks in advance,

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Ryan

Answer 1

You can select a row, but you cannot select a column.

An often made mistake is that some think that an whatever DataGrid is a spreadsheet; it is not

A DataGrid exist from rows of items which get there (same) description because they are in the same column.

However a column itself is not a collection of items like in a spreadsheet.

 

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Success
Cor

Answer 2

Better to use MouseUp instead of MouseDown, otherwise, the column sort may unselect the cells.

And change your code as:

  If e.Button = Windows.Forms.MouseButtons.Left Then

    Dim dgv As DataGridView = CType(sender, DataGridView)
    Dim ht As DataGridView.HitTestInfo = dgv.HitTest(e.X, e.Y)

    dgv.SuspendLayout()

    Select Case ht.Type

      ' select all cells
      Case Is = DataGridViewHitTestType.TopLeftHeader
        dgv.ClearSelection()
        dgv.SelectAll()

        'select the entire column
      Case Is = DataGridViewHitTestType.ColumnHeader
        dgv.ClearSelection()
        dgv.Columns(ht.ColumnIndex).Selected = True
        For i As Integer = 0 To dgv.Rows.Count - 1
          dgv.Rows(i).Cells(ht.ColumnIndex).Selected = True
        Next

        'select all cells in the row entire row
      Case Is = DataGridViewHitTestType.RowHeader
        dgv.ClearSelection()
        dgv.Rows(ht.RowIndex).Selected = True
        For i As Integer = 0 To dgv.Columns.Count - 1
          dgv.Rows(ht.RowIndex).Cells(i).Selected = True
        Next
    End Select
    dgv.ResumeLayout()
  End If

---

Bob Bao [MSFT]
MSDN Community Support | Feedback to us

Answer 3

Hi,

Can't you use 3rd party tool?

Answer 4

Cor, I realize the DataGridView is made up of a collection of rows and not a collection of columns.  However, the end user does not know that the DataGridView functions differently from a spreadsheet so I try my best to accommodate for that.

Thanks Bob for the showing me the ClearSelection() method.  I did not know about this and I can use this in other places in my application.

I figured out a work around last night.  Since the DataGridView has its SelectionMode = "CellSelect" at design time, I decided to keep my MouseDown event and ask the user to hold the Ctrl key while selecting Columns or Rows.  If the Ctrl key is held down I change the SelectionMode to "FullColumnSelect" or "ColumnHeaderSelect".  What do you think?

    Private Sub DGV_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles dgvPending.MouseDown, dgvCurrent.MouseDown, dgvCompleted.MouseDown

        If e.Button = Windows.Forms.MouseButtons.Left Then

            Dim dgv As DataGridView = CType(sender, DataGridView)

            Select Case dgv.HitTest(e.X, e.Y).Type

                ' select all cells
                Case Is = DataGridViewHitTestType.TopLeftHeader
                    dgv.ClearSelection()
                    dgv.SelectAll()

                    'select the entire column
                Case Is = DataGridViewHitTestType.ColumnHeader

                    ' user must click column header + Ctrl key to select all cells in a column, if not the column can be moved to change display index 
                    If Control.ModifierKeys = Keys.Control Then
                        ' allows user to select all cells in the column
                        dgv.SelectionMode = DataGridViewSelectionMode.ColumnHeaderSelect
                        ' un-select the current cell if it is not part of the selected columns
                        If Not dgv.SelectedColumns.Contains(dgv.Columns(dgv.CurrentCell.ColumnIndex)) Then
                            dgv.CurrentCell.Selected = False
                        End If
                    Else
                        ' this is the dgv default setting so users can left click column header and move column to change display index
                        dgv.SelectionMode = DataGridViewSelectionMode.CellSelect
                    End If

                    'select all cells in the row entire row
                Case Is = DataGridViewHitTestType.RowHeader

                    ' user must click row header + Ctrl key to select all cells in the row
                    If Control.ModifierKeys = Keys.Control Then
                        ' allows user to select all cells in the row
                        dgv.SelectionMode = DataGridViewSelectionMode.RowHeaderSelect
                        ' un-select the current cell if it is not part of the selected rows
                        If Not dgv.SelectedRows.Contains(dgv.Rows(dgv.CurrentCell.RowIndex)) Then
                            dgv.CurrentCell.Selected = False
                        End If
                    Else
                        ' this is the dgv default setting so users can left click column header and move column to change display index
                        dgv.SelectionMode = DataGridViewSelectionMode.CellSelect
                    End If
            End Select
        End If

    End Sub

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Ryan

Answer 5

Hi Ryan,

Of couse, it can. You just define the rules.

However, for a the user experience, you should listen the customers' feedback for this rule, press CLT and we can select the Row and Column.

For the feature and the code, that is fine.

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Bob Bao [MSFT]
MSDN Community Support | Feedback to us