ArgumentException when adding ComboBox column to DataGridView with same data source
I have one DataGridView
with custom columns.
But when I add " DataGridViewComboBoxColumn
" and give it a list of my model class as DataSource
, then I had the following error:
System.ArgumentException: The DataGridViewComboBoxCell value is not valid.
New EDIT: 4/9/2009 "More"
I have a named class SmsPart
that has the following properties:
public class SmsPart
{
public int ID
public SmsPart Parent
public string Name
// and more
}
I have a method called GetSmsParts
"return List<SmsPart>
".
I want the column Parent
in the DataGridView to be a ComboBoxColumn to select which part is the parent of the selected part.
So for this reason I created a "DataGridViewComboBoxColumn" and set the DataSource for it to the same DataSource for the hole DataGridView , which is the GetsmsParts method ":
DataGridViewComboBoxColumn comboCulomn = new DataGridViewComboBoxColumn();
comboCulomn.DataSource = listParts;
comboCulomn.DataPropertyName = "Parent";
comboCulomn.DisplayMember = "Name";
comboCulomn.ValueMember = "ID";
comboCulomn.Name = "Parent";
dgvParts.Columns.Add(comboCulomn);
But I always have this error message:
System.ArgumentException: The DataGridViewComboBoxCell value is not valid.
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try assigning a data field name to the property ValueMember
clm2
. While you are specifying what the value type is typeof(smsType)
, you are not specifying the ComboBox column which field to use for the value.
EDIT
Wait a second: Is your smsType
complex type or something else? I'm not sure if any restrictions apply here, but for example, you should use something like int
or string
or like this (whatever you would normally expect to store as a database field).
Also, of course, the type of the DataGridView
underlying data source column (in your example named "Type") must also be the same type as ValueMember
!
EDIT 2
In a second comment: Imagine a database table called "tbl" that contains (among others) one column called "Type" that is of type Integer
. You are displaying the contents of this table in a DataGridView and you want the user to be able to select values for the Type column from the combo box. This is about the scenario you are talking about.
- it is not possible to store complex types like the ones you use in database columns, so you cannot use complex types for a field
Value
inDataGridViewComboBoxColumn
. - To bind the data for the entire grid, you must bind the grid to the "tbl" database table. To create
DataGridViewComboBoxColumn
, you need to assign a list of possible values to a column and tell the column the field in the DataGridView data source that stores the selected value, which field is used as the display value, and which field is used as the value that is stored in the column of the underlying data source.
This means that in the example (if the data source for the column contains the "Value" and "Name" properties):
DataGridViewComboBoxColumn col = new ...
col.DataSource = columnDataSource;
col.DisplayMember = "Name";
col.ValueMember = "Value";
col.DataPropertyName = "Type";
It's all. However, the type of the property assigned to "ValueMember" cannot be a complex type (class / structure) if I remember correctly ...
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The DataGridViewComboBoxColumn restricts the entry of values into the DataSource. I had the same problem. I was trying to set the value of a field outside the DGV. I have bound DGV to DataTable. If I set the DataRow ["somefield"] to a value not contained in the DataSource, I get the error you get.
I ended up creating a DataGridViewColumn descendant that supports the ComboBox editor and accepts values not contained in the DataSource.
I can post the code if you'd like to see it.
EDIT: Here's an example of a ComboBox column
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms.VisualStyles;
namespace YourNamespaceHere
{
/// <summary>
/// DataGridView TextBox column with Items support.
/// </summary>
public class DropTextBoxColumn : DataGridViewColumn
{
[Browsable(false)]
public IEnumerable<string> Items { get; set; }
public ComboBoxStyle DropDownStyle { get; set; }
public DropTextBoxColumn() : base(new DropTextBoxCell())
{
DropDownStyle = ComboBoxStyle.DropDown;
}
private DataGridViewCell cellTemplate = new DropTextBoxCell();
public override DataGridViewCell CellTemplate
{
get
{
return cellTemplate;
}
set
{
// Ensure that the cell used for the template is a DropTextBoxCell.
if (value != null &&
!value.GetType().IsAssignableFrom(typeof(DropTextBoxCell)))
{
throw new InvalidCastException("Must be a DropTextBoxCell");
}
cellTemplate = value;
}
}
}
public class DropTextBoxCell : DataGridViewTextBoxCell
{
[Browsable(false)]
public string[] Items { get; set; }
public DropTextBoxCell() : base() { }
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)
{
base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, paintParts);
//draw a drop down button
if ( (cellState & DataGridViewElementStates.Selected) != 0)
{
var cb = cellBounds;
var r = new Rectangle(cb.Right - cb.Height, cb.Top, cb.Height, cb.Height);
//ComboBoxRenderer.DrawTextBox(graphics, cb, formattedValue as string, this.Style.Font ?? DataGridView.Font, ComboBoxState.Normal);
ComboBoxRenderer.DrawDropDownButton(graphics, r, ComboBoxState.Normal);
}
}
public override void InitializeEditingControl(int rowIndex, object
initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
{
// Set the value of the editing control to the current cell value.
base.InitializeEditingControl(rowIndex, initialFormattedValue,
dataGridViewCellStyle);
DropTextBoxEditingControl ctl =
DataGridView.EditingControl as DropTextBoxEditingControl;
var value = this.Value.ToString();
ctl.Loading = true;
DropTextBoxColumn col = DataGridView.Columns[this.ColumnIndex] as DropTextBoxColumn;
ctl.DropDownStyle = col.DropDownStyle;
ctl.Items.Clear();
if (col.Items != null)
ctl.Items.AddRange(col.Items.ToArray());
ctl.EditingControlFormattedValue = value;
ctl.Loading = false;
}
public override Type EditType
{
get
{
// Return the type of the editing contol that CalendarCell uses.
return typeof(DropTextBoxEditingControl);
}
}
public override Type ValueType
{
get
{
// Return the type of the value that CalendarCell contains.
return typeof(string);
}
}
public override object DefaultNewRowValue
{
get
{
// Use the current date and time as the default value.
return string.Empty;
}
}
}
class DropTextBoxEditingControl : ComboBox, IDataGridViewEditingControl
{
DataGridView dataGridView;
private bool valueChanged = false;
int rowIndex;
public bool Loading { get; set; }
int originalIndex = -1;
public DropTextBoxEditingControl()
{
//this.Format = DateTimePickerFormat.Short;
DropDownStyle = ComboBoxStyle.DropDown;
FlatStyle = FlatStyle.Flat;
}
// Implements the IDataGridViewEditingControl.EditingControlFormattedValue
// property.
public object EditingControlFormattedValue
{
get
{
return Text;
}
set
{
if (value is String)
{
if (DropDownStyle == ComboBoxStyle.DropDown)
Text = value.ToString();
else
{
SelectedIndex = originalIndex = Items.IndexOf(value);
}
}
}
}
// Implements the
// IDataGridViewEditingControl.GetEditingControlFormattedValue method.
public object GetEditingControlFormattedValue(
DataGridViewDataErrorContexts context)
{
return EditingControlFormattedValue;
}
// Implements the
// IDataGridViewEditingControl.ApplyCellStyleToEditingControl method.
public void ApplyCellStyleToEditingControl(
DataGridViewCellStyle dataGridViewCellStyle)
{
this.Font = dataGridViewCellStyle.Font;
}
// Implements the IDataGridViewEditingControl.EditingControlRowIndex
// property.
public int EditingControlRowIndex
{
get
{
return rowIndex;
}
set
{
rowIndex = value;
}
}
// Implements the IDataGridViewEditingControl.EditingControlWantsInputKey
// method.
public bool EditingControlWantsInputKey(
Keys key, bool dataGridViewWantsInputKey)
{
// Let the DateTimePicker handle the keys listed.
//switch (key & Keys.KeyCode)
//{
// case Keys.Left:
// case Keys.Up:
// case Keys.Down:
// case Keys.Right:
// case Keys.Home:
// case Keys.End:
// case Keys.PageDown:
// case Keys.PageUp:
// return true;
// default:
// return !dataGridViewWantsInputKey;
//}
return DroppedDown;
}
// Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit
// method.
public void PrepareEditingControlForEdit(bool selectAll)
{
// No preparation needs to be done.
}
// Implements the IDataGridViewEditingControl
// .RepositionEditingControlOnValueChange property.
public bool RepositionEditingControlOnValueChange
{
get
{
return false;
}
}
// Implements the IDataGridViewEditingControl
// .EditingControlDataGridView property.
public DataGridView EditingControlDataGridView
{
get
{
return dataGridView;
}
set
{
dataGridView = value;
}
}
// Implements the IDataGridViewEditingControl
// .EditingControlValueChanged property.
public bool EditingControlValueChanged
{
get
{
return valueChanged;
}
set
{
valueChanged = value;
}
}
// Implements the IDataGridViewEditingControl
// .EditingPanelCursor property.
public Cursor EditingPanelCursor
{
get
{
return base.Cursor;
}
}
protected override void OnSelectedItemChanged(EventArgs e)
{
if (Loading) return;
// Notify the DataGridView that the contents of the cell
// have changed.
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
base.OnSelectedItemChanged(e);
}
protected override void OnSelectedIndexChanged(EventArgs e)
{
if (Loading || DroppedDown) return;
// Notify the DataGridView that the contents of the cell
// have changed.
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
base.OnSelectedIndexChanged(e);
SendKeys.Send("{ENTER}");
}
protected override void OnTextChanged(EventArgs e)
{
if (Loading) return;
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
base.OnTextChanged(e);
}
protected override void OnDropDownClosed(EventArgs e)
{
if (originalIndex != SelectedIndex)
{
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
}
base.OnDropDownClosed(e);
}
protected override void OnDropDown(EventArgs e)
{
//set dropdown width to accomodate items
var g = CreateGraphics();
DropDownWidth =
Items.Cast<string>().Max(s =>
{
var size = g.MeasureString(s, Font);
return size.Width.To<int>() + 30;
});
base.OnDropDown(e);
}
protected override void OnEnter(EventArgs e)
{
base.OnEnter(e);
DroppedDown = true;
}
}
}
Here's a usage example
var dc = new DropTextBoxColumn();
dc.Name = "FieldName";
dc.DataPropertyName = "FieldName";
dc.DropDownStyle = ComboBoxStyle.DropDownList;
var items = dc.Items = new string[]{ "one", "two", "three" };
items.Insert(0, "<None>");
dc.Items = items;
DirectGrid.Columns.Insert(1,dc);
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