How to have custom control in DataGridView display object's value?

Question

I have a sample project located
here
The project has a main form `Form1` where the user can enter customers in a datagridview. The `CustomerType` column is a custom control and when the user clicks the button, a search form `Form2` pops up.
The search form is populated with a list of type `CustomerType`. The user can select a record by double-clicking on the row, and this object should be set in the custom control. The `DataGridView` should then display the `Description` property but in the background
each cell should hold the value (ie. the `CustomerType` instance).
The relevant code is located in the following classes:
The column class:
public class DataGridViewCustomerTypeColumn : DataGridViewColumn
public DataGridViewCustomerTypeColumn()
: base(new CustomerTypeCell())
public override DataGridViewCell CellTemplate
get { return base.CellTemplate; }
set
if (value != null && !value.GetType().IsAssignableFrom(typeof(CustomerTypeCell)))
throw new InvalidCastException("Should be CustomerTypeCell.");
base.CellTemplate = value;
The cell class:
public class CustomerTypeCell : DataGridViewTextBoxCell
public CustomerTypeCell()
: base()
public override void InitializeEditingControl(int rowIndex, object initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
base.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle);
CustomerTypeSearch ctl = DataGridView.EditingControl as CustomerTypeSearch;
if (this.Value == null)
ctl.Value = (CustomerType)this.DefaultNewRowValue;
else
ctl.Value = (CustomerType)this.Value;
public override Type EditType
get { return typeof(CustomerTypeSearch); }
public override Type ValueType
get { return typeof(CustomerType); }
public override object DefaultNewRowValue
get { return null; }
And the custom control:
public partial class CustomerTypeSearch : UserControl, IDataGridViewEditingControl
private DataGridView dataGridView;
private int rowIndex;
private bool valueChanged = false;
private CustomerType value;
public CustomerTypeSearch()
InitializeComponent();
public CustomerType Value
get { return this.value; }
set
this.value = value;
if (value != null)
textBoxSearch.Text = value.Description;
else
textBoxSearch.Clear();
private void buttonSearch_Click(object sender, EventArgs e)
Form2 f = new Form2();
DialogResult dr = f.ShowDialog(this);
if (dr == DialogResult.OK)
Value = f.SelectedValue;
#region IDataGridViewEditingControl implementation
public object EditingControlFormattedValue
get
if (this.value != null)
return this.value.Description;
else
return null;
set
if (this.value != null)
this.value.Description = (string)value;
public object GetEditingControlFormattedValue(DataGridViewDataErrorContexts context)
return EditingControlFormattedValue;
public void ApplyCellStyleToEditingControl(DataGridViewCellStyle dataGridViewCellStyle)
this.BorderStyle = BorderStyle.None;
this.Font = dataGridViewCellStyle.Font;
public int EditingControlRowIndex
get { return rowIndex; }
set { rowIndex = value; }
public bool EditingControlWantsInputKey(Keys key, bool dataGridViewWantsInputKey)
return false;
public void PrepareEditingControlForEdit(bool selectAll)
//No preparation needs to be done
public bool RepositionEditingControlOnValueChange
get { return false; }
public DataGridView EditingControlDataGridView
get { return dataGridView; }
set { dataGridView = value; }
public bool EditingControlValueChanged
get { return valueChanged; }
set { valueChanged = value; }
public Cursor EditingPanelCursor
get { return base.Cursor; }
#endregion
private void CustomerTypeSearch_Resize(object sender, EventArgs e)
buttonSearch.Left = this.Width - buttonSearch.Width;
textBoxSearch.Width = buttonSearch.Left;
However, the `DataGridView` is not displaying the text and it also is not keeping the `CustomerType` value for each cell.
What am I missing?
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Answer 1

Hello,
1. To display the text, we need to override the ToString method for CustomerType
public class CustomerType
public int Id { get; set; }
public string Description { get; set; }
public CustomerType(int id, string description)
this.Id = id;
this.Description = description;
public override string ToString()
return this.Description.ToString();
2. To get the cell's value changed, we could pass the cell instance to that editing control and get its value changed with the following way.
public partial class CustomerTypeSearch : UserControl, IDataGridViewEditingControl
private DataGridView dataGridView;
private int rowIndex;
private bool valueChanged = false;
private CustomerTypeCell currentCell = null;
public CustomerTypeCell OwnerCell
get { return currentCell; }
set
currentCell = null;
currentCell = value;
public CustomerTypeSearch()
InitializeComponent();
private void buttonSearch_Click(object sender, EventArgs e)
Form2 f = new Form2();
DialogResult dr = f.ShowDialog(this);
if (dr == DialogResult.OK)
currentCell.Value = f.SelectedValue;
this.textBoxSearch.Text = f.SelectedValue.Description;
#region IDataGridViewEditingControl implementation
public object EditingControlFormattedValue
get
if (this.currentCell.Value != null)
return (this.currentCell.Value as CustomerType).Description;
else
return null;
set
if (this.currentCell != null)
(this.currentCell.Value as CustomerType).Description = (string)value;
public object GetEditingControlFormattedValue(DataGridViewDataErrorContexts context)
return EditingControlFormattedValue;
public void ApplyCellStyleToEditingControl(DataGridViewCellStyle dataGridViewCellStyle)
this.BorderStyle = BorderStyle.None;
this.Font = dataGridViewCellStyle.Font;
public int EditingControlRowIndex
get { return rowIndex; }
set { rowIndex = value; }
public bool EditingControlWantsInputKey(Keys key, bool dataGridViewWantsInputKey)
return false;
public void PrepareEditingControlForEdit(bool selectAll)
//No preparation needs to be done
public bool RepositionEditingControlOnValueChange
get { return false; }
public DataGridView EditingControlDataGridView
get { return dataGridView; }
set { dataGridView = value; }
public bool EditingControlValueChanged
get { return valueChanged; }
set { valueChanged = value; }
public Cursor EditingPanelCursor
get { return base.Cursor; }
#endregion
private void CustomerTypeSearch_Resize(object sender, EventArgs e)
buttonSearch.Left = this.Width - buttonSearch.Width;
textBoxSearch.Width = buttonSearch.Left;
Cell:
public class CustomerTypeCell : DataGridViewTextBoxCell
public CustomerTypeCell()
: base()
public override void InitializeEditingControl(int rowIndex, object initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
base.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle);
CustomerTypeSearch ctl = DataGridView.EditingControl as CustomerTypeSearch;
ctl.OwnerCell = this;
public override Type EditType
get { return typeof(CustomerTypeSearch); }
public override Type ValueType
get { return typeof(CustomerType); }
public override object DefaultNewRowValue
get { return null; }
Result:
Regards,
Carl
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