Create Custom DataGridView Column

Hello Abubakr Mahdi,

Try below code.

using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
namespace DataGridViewWatermark
{
public class DataGridViewWatermarkColumn : DataGridViewTextBoxColumn
{
public DataGridViewWatermarkColumn()
{
CellTemplate = new DataGridViewWatermarkCell();
}
public String WatermarkText
{
get
{
if (((DataGridViewWatermarkCell)CellTemplate) == null)
{
throw new InvalidOperationException("cell template required");
}
return ((DataGridViewWatermarkCell)CellTemplate).WatermarkText;
}
set
{
if (this.WatermarkText != value)
{
((DataGridViewWatermarkCell)CellTemplate).WatermarkText = value;
if (this.DataGridView != null)
{
DataGridViewRowCollection dataGridViewRows =
this.DataGridView.Rows;
int rowCount = dataGridViewRows.Count;
for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
{
DataGridViewRow dataGridViewRow =
dataGridViewRows.SharedRow(rowIndex);
DataGridViewWatermarkCell cell =
dataGridViewRow.Cells[this.Index]
as DataGridViewWatermarkCell;
if (cell != null)
{
cell.WatermarkText = value;
}
}
}
}
}
}
}
public class DataGridViewWatermarkCell : DataGridViewTextBoxCell
{
private String watermarkTextValue;
public String WatermarkText
{
get { return watermarkTextValue; }
set { watermarkTextValue = value; }
}
public override object Clone()
{
DataGridViewWatermarkCell cell = (DataGridViewWatermarkCell)base.Clone();
cell.WatermarkText = this.WatermarkText;
return cell;
}
protected override void Paint(Graphics graphics, Rectangle clipBounds,
Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState,
object value, object formattedValue, string errorText,
DataGridViewCellStyle cellStyle,
DataGridViewAdvancedBorderStyle advancedBorderStyle,
DataGridViewPaintParts paintParts)
{
if ((OwningColumn.Site == null || !OwningColumn.Site.DesignMode) &&
(RowIndex < 0 || !IsInEditMode) && !String.IsNullOrEmpty(WatermarkText) &&
(GetValue(rowIndex) == null || GetValue(rowIndex) == DBNull.Value))
{
cellStyle.Font = new Font(cellStyle.Font, FontStyle.Italic);
cellStyle.ForeColor = Color.Gray;
formattedValue = WatermarkText;
}
base.Paint(graphics, clipBounds, cellBounds, rowIndex,
cellState, value, formattedValue, errorText,
cellStyle, advancedBorderStyle, paintParts);
}
}
}

Rferences:
https://docs.microsoft.com/en-us/dotnet/framework/winforms/controls/customize-cells-and-columns-in-the-datagrid-by-extending-behavior
https://docs.microsoft.com/en-us/dotnet/framework/winforms/controls/customizing-the-windows-forms-datagridview-control
https://www.codemag.com/article/0707061/Create-a-Custom-DataGridView-Column

Video links:
https://www.youtube.com/watch?v=vHkYITRArgA
https://www.youtube.com/watch?v=crxsHjuMjE4

Best of luck..

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Elavarasan R7y ago
Accepted answer
Hello Abubakr Mahdi,
Try below code.
using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
namespace DataGridViewWatermark
{
    public class DataGridViewWatermarkColumn : DataGridViewTextBoxColumn

    {
        public DataGridViewWatermarkColumn()
        {
            CellTemplate = new DataGridViewWatermarkCell();
        }
        public String WatermarkText
        {
            get
            {
                if (((DataGridViewWatermarkCell)CellTemplate) == null)
                {
                    throw new InvalidOperationException("cell template required");
                }
                return ((DataGridViewWatermarkCell)CellTemplate).WatermarkText;
            }
            set

            {

                if (this.WatermarkText != value)
                {
                    ((DataGridViewWatermarkCell)CellTemplate).WatermarkText = value;
                    if (this.DataGridView != null)
                    {
                        DataGridViewRowCollection dataGridViewRows =
                            this.DataGridView.Rows;
                        int rowCount = dataGridViewRows.Count;
                        for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
                        {
                            DataGridViewRow dataGridViewRow =
                                dataGridViewRows.SharedRow(rowIndex);
                            DataGridViewWatermarkCell cell =
                                dataGridViewRow.Cells[this.Index]
                                as DataGridViewWatermarkCell;
                            if (cell != null)
                            {
                                cell.WatermarkText = value;
                            }
                        }
                    }
                }
            }
        }
    }
    public class DataGridViewWatermarkCell : DataGridViewTextBoxCell

    {
        private String watermarkTextValue;
        public String WatermarkText
        {
            get { return watermarkTextValue; }
            set { watermarkTextValue = value; }
        }
        public override object Clone()
        {
            DataGridViewWatermarkCell cell = (DataGridViewWatermarkCell)base.Clone();
            cell.WatermarkText = this.WatermarkText;
            return cell;
        }
        protected override void Paint(Graphics graphics, Rectangle clipBounds,
            Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState,
            object value, object formattedValue, string errorText,
            DataGridViewCellStyle cellStyle,
            DataGridViewAdvancedBorderStyle advancedBorderStyle,
            DataGridViewPaintParts paintParts)
        {
            if ((OwningColumn.Site == null || !OwningColumn.Site.DesignMode) &&
                (RowIndex < 0 || !IsInEditMode) && !String.IsNullOrEmpty(WatermarkText) &&
                (GetValue(rowIndex) == null || GetValue(rowIndex) == DBNull.Value))
            {
                cellStyle.Font = new Font(cellStyle.Font, FontStyle.Italic);
                cellStyle.ForeColor = Color.Gray;
                formattedValue = WatermarkText;
            }
            base.Paint(graphics, clipBounds, cellBounds, rowIndex,
                cellState, value, formattedValue, errorText,
                cellStyle, advancedBorderStyle, paintParts);
        }
    }
}
Rferences:
https://docs.microsoft.com/en-us/dotnet/framework/winforms/controls/customize-cells-and-columns-in-the-datagrid-by-extending-behavior
https://docs.microsoft.com/en-us/dotnet/framework/winforms/controls/customizing-the-windows-forms-datagridview-control
https://www.codemag.com/article/0707061/Create-a-Custom-DataGridView-Column

Video links:
https://www.youtube.com/watch?v=vHkYITRArgA
https://www.youtube.com/watch?v=crxsHjuMjE4
Best of luck..
+3