How to add the RadioButton column in WinForms DataGrid (SfDataGrid)?

About the sample

This example illustrates how to add the radio button column in winforms datagrid

By default, SfDataGrid doesn’t have a build in RadioButtonColumn, but we can create the GridRadioButtonColumn by customizing the GridColumn, RadioButtonAdv and GridCellRendererBase in SfDataGrid.

[ToolboxItem(false)]
public partial class GridCellRadioButton : RadioButtonAdv
{
    public GridCellRadioButton()
    {
    }

    /// <summary>
    /// Draws  check mark of the radio button.
    /// </summary>
    /// <param name="g">Graphics object</param>
    public void DrawSelectedCheckMark(Graphics g, Rectangle mrectBox, RadioButtonAdv radio, Color circleBackColor, Color iconColor)
    {
        Rectangle rect = mrectBox;
        rect.Inflate((int)DpiAware.LogicalToDeviceUnits(-5), (int)DpiAware.LogicalToDeviceUnits(-5));

        using (Pen pen = new Pen(circleBackColor))
        {
            g.DrawEllipse(pen, rect);
        }

        rect.Inflate(-1, -1);

        using (GraphicsPath path = this.GetCheckMarkPath(rect))
        {
            using (PathGradientBrush brush = new PathGradientBrush(path))
            {
                brush.CenterColor = iconColor;
                brush.CenterPoint = new PointF((float)rect.X + 1, (float)rect.Y + 1);
                brush.SurroundColors = new Color[] { iconColor };
                SmoothingMode mode = SmoothingMode.AntiAlias;
                g.SmoothingMode = mode;
                g.FillPath(brush, path);
            }
        }

        using (GraphicsPath path = this.GetCheckMarkBorderPath(rect))
        {
            using (Pen pen = new Pen(iconColor))
            {
                g.DrawPath(pen, path);
            }
        }
    }

    internal GraphicsPath GetCheckMarkBorderPath(Rectangle rect)
    {
        GraphicsPath path = new GraphicsPath();

        #region Fortouch
        path.AddEllipse(rect);
        path.CloseFigure();
        #endregion
        return path;
    }

    internal GraphicsPath GetCheckMarkPath(Rectangle rect)
    {
        GraphicsPath path = new GraphicsPath();
        path.AddEllipse(rect);
        path.CloseFigure();
        return path;
    }

    public void DrawBorder(Graphics g, Color borderColor, Rectangle mrectBox, RadioButtonAdv radioButtonAdv)
    {
        Rectangle rect = mrectBox;
        rect.Inflate(-1, -1);
        g.SmoothingMode = SmoothingMode.AntiAlias;
        g.CompositingQuality = CompositingQuality.AssumeLinear;

        using (Pen pen = new Pen(borderColor))
        {
            pen.Width = 1;
            g.DrawEllipse(pen, rect);
        }
    }
}

public class GridRadioButtonCellRender : GridCellRendererBase
{
    public GridRadioButtonCellRender(SfDataGrid dataGrid, Options options)
    {
        IsEditable = true;
        DataGrid = dataGrid;
        RadioOptions = options;
    }

    protected Options RadioOptions { get; set; }

    protected List<GridCellRadioButton> RadioButtonCollection { get; set; }

    /// <summary>
    /// Gets or Sets to specifies the datagrid.
    /// </summary>
    protected SfDataGrid DataGrid { get; set; }

    protected override void OnRender(Graphics paint, Rectangle cellRect, string cellValue, CellStyleInfo style, DataColumnBase column, RowColumnIndex rowColumnIndex)
    {
        int starHeight, starWidth;
        Rectangle drawArea;

        var padding = 5;
        starWidth = 16;
        starHeight = 16;

        var RadioButtonColumn = column.GridColumn as GridRadioButtonColumn;
        drawArea = new Rectangle(cellRect.X + padding, cellRect.Y + ((cellRect.Height / 2) - (starHeight / 2)), starWidth, starHeight);

        RadioButtonCollection = new List<GridCellRadioButton>();
        for (int i = 0; i < RadioButtonColumn.ItemCount; i++)
        {
            var radioButton = new GridCellRadioButton();

            radioButton.Location = new Point(drawArea.X, drawArea.Y);
            radioButton.Width = starWidth;
            radioButton.Height = starHeight;

            //Draw outer border of RadioButton
            radioButton.DrawBorder(paint, Color.Black, drawArea, radioButton);

            Point point = new Point(drawArea.X + drawArea.Width + 2, drawArea.Y);
            Font font = style.GetFont() != Control.DefaultFont ? style.GetFont() : Control.DefaultFont;

            int value = i;
            var buttonValue = ((Options)value).ToString();

            //Draw string for RadioButton
            paint.DrawString(buttonValue, font, new SolidBrush(Color.Gray), point);
            if (buttonValue.Equals(cellValue))
            {
                radioButton.DrawSelectedCheckMark(paint, drawArea, radioButton, Color.Black, Color.Black);
            }
            //Add RadioButton to Cell
            RadioButtonCollection.Add(radioButton);

            //Set the start point for next RadioButton
            Size stringlenth = TextRenderer.MeasureText((RadioOptions = 0).ToString(), font);
            drawArea.X += drawArea.Width + 10 + stringlenth.Width;
        }
    }

    protected override void OnMouseDown(DataColumnBase dataColumn, RowColumnIndex rowColumnIndex, MouseEventArgs e)
    {
        var radiobuttoncollection = (dataColumn.Renderer as GridRadioButtonCellRender).RadioButtonCollection;
        PropertyInfo dataRow = (dataColumn as DataColumnBase).GetType().GetProperty("DataRow", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
        DataRow rowdata = (DataRow)dataRow.GetValue(dataColumn as DataColumnBase);

        for (int i = 0; i < radiobuttoncollection.Count; i++)
        {
            var rect = radiobuttoncollection[i].Bounds;
            if (e.Location.X > rect.X && e.Location.X < (rect.X + rect.Width))
            {
                radiobuttoncollection[i].Checked = true;
                (rowdata.RowData as OrderInfo).RadioOptions = (Options)i;

                DataGrid.TableControl.Invalidate(rect, true);

            }
        }
    }
}

public class GridRadioButtonColumn : GridColumn
{
    public GridRadioButtonColumn()
    {
        SetCellType("RadioButton");
    }

    private int itemCount;
    public int ItemCount
    {
        get
        {
            return itemCount;
        }
        set
        {
            itemCount = value;
        }
    }
}

this.sfDataGrid1.Columns.Add(new GridRadioButtonColumn() { MappingName = "RadioOptions", ItemCount = 3, Width = 140 });

Requirements to run the demo

Visual Studio 2015 and above versions