Inserting ComboBoxes in a DataGrid with specific items in each row

resultsDataGridView.DataSource = myDataSet;

{

c.DataSource = (x.similars).ToArray();

}

resultsDataGridView.DataSource = myDataSet;

//****************************************************************

2-using the table style with DataGrid

//**************

DataGridTableStyle tableStyle = new DataGridTableStyle();

DataGridTextBoxColumn columnTextBox;

X.DataGridComboBoxColumn columnComboBox;

DataGridViewComboBoxColumn cv ;

columnTextBox = new DataGridTextBoxColumn();

columnTextBox.Alignment = HorizontalAlignment.Left;

columnTextBox.ReadOnly = true;

columnTextBox = new DataGridTextBoxColumn();

columnTextBox.Alignment = HorizontalAlignment.Right;

columnTextBox.ReadOnly = true;

columnComboBox = new X.DataGridComboBoxColumn();

columnComboBox.Alignment = HorizontalAlignment.Right;

columnComboBox.ReadOnly = true;

tableStyle.AlternatingBackColor = Color.Gainsboro;

tableStyle.AllowSorting = false;

tableStyle.ReadOnly = true;

dataGrid1.DataMember = "Tags Table with ComboBox";

//*************

where X namespace has the definition of the DataGridComboBoxColumn class as follows:

//----------------

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

namespace X

#region DataGridComboBoxColumn

//**********************************************************************************************

// DataGridComboBoxColumn

//**********************************************************************************************

public class DataGridComboBoxColumn : DataGridColumnStyle

private DataGridComboBox combobox;

private bool edit;

//-------------------------------------------------------------------------------------------

// Constructors and destructors

//-------------------------------------------------------------------------------------------

public DataGridComboBoxColumn()

combobox = new DataGridComboBox();

combobox.Visible = false;

combobox.DropDownStyle = ComboBoxStyle.DropDownList;

combobox.Leave += new EventHandler(ComboHide);

combobox.SelectionChangeCommitted += new EventHandler(ComboStartEditing);

edit = false;

} // DataGridComboBoxColumn

//-------------------------------------------------------------------------------------------

// Properties

//-------------------------------------------------------------------------------------------

public ComboBox comboBox

get

return combobox;

} // comboBox

//-------------------------------------------------------------------------------------------

// ComboBox event handlers

//-------------------------------------------------------------------------------------------

private void ComboHide(object sender, EventArgs e)

// When the ComboBox looses focus, then simply hide it.

} // ComboHide

private void ComboStartEditing(object sender, EventArgs e)

// Enter edit mode.

edit = true;

base.ColumnStartedEditing((Control)sender);

} // ComboStartEditing

//-------------------------------------------------------------------------------------------

// Override DataGridColumnStyle

//-------------------------------------------------------------------------------------------

protected override void SetDataGridInColumn(DataGrid value)

// Add the ComboBox to the DataGrids controls collection.

// This ensures correct DataGrid scrolling.

base.SetDataGridInColumn(value);

} // SetDataGridInColumn

protected override void Abort(int rowNum)

// Abort edit mode, discard changes and hide the ComboBox.

edit = false;

} // Abort

protected override void Edit(System.Windows.Forms.CurrencyManager source, int rowNum, System.Drawing.Rectangle bounds, bool readOnly, string instantText, bool cellIsVisible)

// Setup the ComboBox for action.

// This includes positioning the ComboBox and showing it.

// Also select the correct item in the ComboBox before it is shown.

combobox.Parent = this.DataGridTableStyle.DataGrid;

combobox.Size = new Size(this.Width, this.comboBox.Height);

comboBox.SelectedValue = base.GetColumnValueAtRow(source, rowNum).ToString();

combobox.Visible = (cellIsVisible == true) && (readOnly == false);

} // Edit

protected override bool Commit(System.Windows.Forms.CurrencyManager source, int rowNum)

// Commit the selected value from the ComboBox to the DataGrid.

if (edit == true)

edit = false;

this.SetColumnValueAtRow(source, rowNum, combobox.SelectedValue);

return true;

} // Commit

protected override object GetColumnValueAtRow(System.Windows.Forms.CurrencyManager source, int rowNum)

// Return the display text associated with the data, insted of the

// data from the DataGrid datasource.

return combobox.GetDisplayText(base.GetColumnValueAtRow(source, rowNum));

} // GetColumnValueAtRow

protected override void SetColumnValueAtRow(CurrencyManager source, int rowNum, object value)

// Save the data (value) to the DataGrid datasource.

// I try a few different types, because I often uses GUIDs as keys in my

// data.

// String.

try

base.SetColumnValueAtRow(source, rowNum, value.ToString());

return;

catch { }

// Guid.

try

base.SetColumnValueAtRow(source, rowNum, new Guid(value.ToString()));

return;

catch { }

// Object (default).

base.SetColumnValueAtRow(source, rowNum, value);

} // SetColumnValueAtRow

protected override int GetMinimumHeight()

// Return the ComboBox preferred height, plus a few pixels.

return combobox.PreferredHeight + 2;

} // GetMinimumHeight

protected override int GetPreferredHeight(Graphics g, object val)

// Return the font height, plus a few pixels.

return FontHeight + 2;

} // GetPreferredHeight

protected override Size GetPreferredSize(Graphics g, object val)

// Return the preferred width.

// Iterate through all display texts in the dropdown, and measure each

// text width.

int widest = 0;

SizeF stringSize = new SizeF(0, 0);

foreach (string text in combobox.GetDisplayText())

stringSize = g.MeasureString(text, base.DataGridTableStyle.DataGrid.Font);

if (stringSize.Width > widest)

widest = (int)Math.Ceiling(stringSize.Width);

return new Size(widest + 25, combobox.PreferredHeight + 2);

} // GetPreferredSize

protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum)

Paint(g, bounds, source, rowNum, false);

} // Paint

protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum, bool alignToRight)

string text = GetColumnValueAtRow(source, rowNum).ToString();

Brush backBrush = new SolidBrush(base.DataGridTableStyle.BackColor);

Brush foreBrush = new SolidBrush(base.DataGridTableStyle.ForeColor);

Rectangle rect = bounds;

StringFormat format = new StringFormat();

// Handle that the row can be selected.

if (base.DataGridTableStyle.DataGrid.IsSelected(rowNum) == true)

backBrush = new SolidBrush(base.DataGridTableStyle.SelectionBackColor);

foreBrush = new SolidBrush(base.DataGridTableStyle.SelectionForeColor);

// Handle align to right.

if (alignToRight == true)

format.FormatFlags = StringFormatFlags.DirectionRightToLeft;

// Handle alignment.

switch (this.Alignment)

case HorizontalAlignment.Left:

format.Alignment = StringAlignment.Near;

break;

case HorizontalAlignment.Right:

format.Alignment = StringAlignment.Far;

break;

case HorizontalAlignment.Center:

format.Alignment = StringAlignment.Center;

break;

// Paint.

format.FormatFlags = StringFormatFlags.NoWrap;

g.DrawString(text, this.DataGridTableStyle.DataGrid.Font, foreBrush, rect, format);

} // PaintText

} // DataGridComboBoxColumn

#region DataGridComboBox

//**********************************************************************************************

// DataGridComboBox

//**********************************************************************************************

public class DataGridComboBox : ComboBox

private const int WM_KEYUP = 0x101;

protected override void WndProc(ref System.Windows.Forms.Message message)

// Ignore keyup to avoid problem with tabbing and dropdown list.

if (message.Msg == WM_KEYUP)

return;

base.WndProc(ref message);

} // WndProc

public string GetValueText(int index)

// Validate the index.

if ((index < 0) && (index >= base.Items.Count))

throw new IndexOutOfRangeException("Invalid index.");

// Get the text.

string text = string.Empty;

int memIndex = -1;

try

base.BeginUpdate();

memIndex = base.SelectedIndex;

base.SelectedIndex = index;

text = base.SelectedValue.ToString();

base.SelectedIndex = memIndex;

catch

finally

base.EndUpdate();

return text;

} // GetValueText

public string GetDisplayText(int index)

// Validate the index.

if ((index < 0) && (index >= base.Items.Count))

throw new IndexOutOfRangeException("Invalid index.");

// Get the text.

string text = string.Empty;

int memIndex = -1;

try

base.BeginUpdate();

memIndex = base.SelectedIndex;

base.SelectedIndex = index;

text = base.SelectedItem.ToString();

base.SelectedIndex = memIndex;

catch

finally

base.EndUpdate();

return text;

} // GetDisplayText

public string GetDisplayText(object value)

// Get the text.

string text = string.Empty;

int memIndex = -1;

try

base.BeginUpdate();

memIndex = base.SelectedIndex;

base.SelectedValue = value.ToString();

text = base.SelectedItem.ToString();

base.SelectedIndex = memIndex;

catch

finally

base.EndUpdate();

return text;

} // GetDisplayText

public string[] GetDisplayText()

// Get the text.

string[] text = new string[base.Items.Count];

int memIndex = -1;

try

base.BeginUpdate();

memIndex = base.SelectedIndex;

for (int index = 0; index < base.Items.Count; index++)

base.SelectedIndex = index;

text[index] = base.SelectedItem.ToString();

base.SelectedIndex = memIndex;

catch

finally

base.EndUpdate();

return text;

} // GetDisplayText

} // DataGridComboBox

//----------------

also the result is empty cells in the column that expected to be ComboBoxes !!.

So, How can I solve that .