Programmatically size a DataGridView

Question

Hi, I posted this in the 'windows forms data controls & databinding forum' but didn't get any response -- so am trying here as well. i'd like to set up a DataGridView with: (a) just a horizontal scroll bar at design time (b) porgrammatically size it vertically to accomodate all rows plus the column header, unless the number rows exceeds N, in which case, programmatically add a vertical scroll bar. The datagridview will not be bound to any data-source. Instead i programmatically add rows to its (initially empty) DataGridViewRowCollection. I have experimented with trying to programmatically determine the height to set it to with the following code: dgv.height = dgv.rows.GetRowsHeight(DataGridViewElementStates.None) + dgv.columnHeadersHeight // where dgv is my DataGridView instance Anyway, this does not seem to work - it falls short of the height it should be. As such, any idea how i'd do (b)? Thanks, Mark

Answer 1

Is is possible that it is off just by some constant value (like the size of the borders, etc)? Then you could just add the constant value to get the correct height.

Answer 2

I wrote this to dynamically resize the width of the datagridView control

    Private Sub ResizeDgVarGrid()
        Dim iWidth As Integer = 0
        Dim maxWidth as Integer=527
        For i As Integer = 0 To dgVarData.Columns.Count - 1
            iWidth += dgVarData.Columns(i).Width
        Next
        If (iWidth + 50) >= maxWidth Then
            Me.dgVarData.ScrollBars = ScrollBars.Horizontal
        Else
            Me.dgVarData.ScrollBars = ScrollBars.None
        End If
    End Sub

I'm sure a similar method would work for height. I have a max width that I have set for form limitation, the '50' is to prevent the horizontal scrollbar appearing

Hope this helps

Answer 3

I put together this basic control to do this for me. It is nothing fancy and I am sure there are sizing issues based on font selected. The application I wrote this for is a very specific usage. That being said you could take this and use it as a starting point to make a more robust control to take into account resolution and font.

 

Basic usage of this is set the "Rows to Display" property either programatically or at design-time. If you specifiy a number of rows to display it will size the grid to display at max that number of rows, if the row count exceeds that number it forces scroll. If you set "Rows to Display" to zero the grid will function normally in this regard.

Code Block

 

public partial class FormattedGridView : DataGridView {

private bool __FirstPaint = true;

private int __RowsToDisplay;

public FormattedGridView() {

InitializeComponent();

}

public int RowsToDisplay {

get { return __RowsToDisplay; }

set { __RowsToDisplay = value; }

}

/// <summary>

/// Adds a confirmation box on deletes.

/// </summary>

private void GridView_UserDeletingRow(object sender, DataGridViewRowCancelEventArgs e) {

if (!e.Row.IsNewRow) {

DialogResult response =

MessageBox.Show("Are you sure you want to delete this record?", "Delete Record?", MessageBoxButtons.YesNo, MessageBoxIcon.Question,

MessageBoxDefaultButton.Button2);

if (response == DialogResult.No) {

e.Cancel = true;

}

}

}

private int GetGridHeight() {

int x = 0;

foreach (DataGridViewRow row in Rows) {

x += row.Height;

}

x += ColumnHeadersHeight;

x += 2;

return x;

}

private int GetMaxGridSize() {

int singleRowHeight = Rows[0].Height;

if (__RowsToDisplay == 0) {

return 300;

}

else {

return singleRowHeight*__RowsToDisplay + ColumnHeadersHeight + 2;

}

}

private void GridView_Paint(object sender, PaintEventArgs e) {

if (__RowsToDisplay == 0) return;

if (__FirstPaint) {

__FirstPaint = false;

MaximumSize = new Size(1024, GetMaxGridSize());

}

Height = GetGridHeight();

}

}

 

 

Answer 4

Im not a 100% sure but u cant show(if set in properties menu) Scrollbars before the number of rows or columns exceeds that of the DGV(DataGridView) height or width, having said that, you will have to find a way to make the DGV grow maybe 1 row before before the last row reaches the bottom of the grid until a certain height, after that the scroll bar will automatically pop up if u set the scroll bar property to vertical but in your case you will want it set to both and that way the bars pop up automatically because u have allowed the rows to reach the bottom of the grid

Public Class Form1
    Dim i As Integer
    Dim cellwidth As Integer
    Dim cellheight As Integer
    Private Sub AddRowsButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles AddRowsButton.Click

        If DataGridView1.Columns.Count < 1 Then

            DataGridView1.Columns.Add("", "")
            cellheight += DataGridView1.Rows(i).Height
            Label1.Text = cellheight.ToString

        Else

            i += 1
            DataGridView1.Rows.Add(1)
            cellheight += DataGridView1.Rows(i).Height
            Label1.Text = cellheight.ToString

            If Not DataGridView1.Height = 400 Then 'this is the point where you want the Grid to stop growing
                If cellheight > DataGridView1.Height - 20 Then ' This is how fine you want the bottom row to reach before grid grow but 
                    'watch how u set it as they catch up with each other 

                    DataGridView1.Height += 20
                End If
            End If
          End If
    End Sub

    Private Sub AddColumnsButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles AddColumnsButton.Click

        DataGridView1.Columns.Add("", "") 'you can do the same for your columns
    End Sub
  
End Class

Remember to enable scroll bars in properties other wise this theory will not work

as i do not know how to force scroll bars to appear before rows/columns have reached the botton/side of grid

Did not realize this was a 2006 post lol