Question

I have a datagridview that is docked and anchored with a panel on a Winform. When I resize the form, the datagridview resizes as expected, but the columns do not resize to fit the datagridview. Instead, I am left with the background colour of the Datagridview.

How can I get the columns to grow with the control?

Thanks.

Answer 1

private void dataGrid_SizeChanged(object sender, EventArgs e)
{
    ResizeGridColumns();
}

private void ResizeGridColumns()
{
    //get sum of non-resizable columns width
    int diffWidth = 0;
    foreach (DataGridViewColumn col in this.dataGrid.Columns)
    {
        if (col.Resizable == DataGridViewTriState.False && col.Visible) diffWidth += col.Width;
    }

    //calculate available width
    int totalResizableWith = this.dataGrid.Width - diffWidth;

    //resize column width based on previous proportions
    this.dataGrid.ColumnWidthChanged -= new DataGridViewColumnEventHandler(dataGrid_ColumnWidthChanged);
    for (int i = 0; i < this.colWidthRaport.Count; i++)
    {
        try
        {
            if (this.dataGrid.Columns[i].Resizable != DataGridViewTriState.False && this.dataGrid.Columns[i].Visible)
            {
                this.dataGrid.Columns[i].Width = (int)Math.Floor((decimal)totalResizableWith / this.colWidthRaport[i]);
            }
        }
        catch { }
    }
    this.dataGrid.ColumnWidthChanged += new DataGridViewColumnEventHandler(dataGrid_ColumnWidthChanged);
}

private void dataGrid_ColumnWidthChanged(object sender, DataGridViewColumnEventArgs e)
{
    CalculateGridColWidthsRaport();
}

/// <summary>Calculates the proportions between grid width and column width</summary>
private void CalculateGridColWidthsRaport()
{
    //get sum of non-resizable columns width
    int diffWidth = 0;
    int colWidthsSum = 0;
    foreach (DataGridViewColumn col in this.dataGrid.Columns)
    {
        if (col.Visible)
        {
            colWidthsSum += col.Width;
            if (col.Resizable == DataGridViewTriState.False) diffWidth += col.Width;
        }
    }
    colWidthsSum += 24;

    //calculate available with
    int totalResizableWith = colWidthsSum - diffWidth;// this.dataGrid.Width - diffWidth;
    if (this.ParentForm.WindowState == FormWindowState.Maximized)
    {
        totalResizableWith = this.dataGrid.Width - diffWidth;
    }

    //calculate proportions of each column relative to the available width
    this.colWidthRaport = new List<decimal>();
    foreach (DataGridViewColumn col in this.dataGrid.Columns)
    {
        this.colWidthRaport.Add((decimal)totalResizableWith / (decimal)col.Width);
    }
}