How do I bind a ComboBox so the displaymember is concat of 2 fields of source datatable?

Question

I'd like to bind a ComboBox to a DataTable (I cannot alter its original schema)

cbo.DataSource = tbldata;
cbo.DataTextField = "Name";
cbo.DataValueField = "GUID";
cbo.DataBind();

I want the ComboBox show tbldata.Name + tbldata.Surname.

Of course adding the new name+surname as a field to the tbldata just before binding is possible, but I am hoping for a more elegant solution along the lines of (pseudocode)

cbo.DataTextField = "Name";
cbo.DataTextField += "Surname";

score 26 · Accepted Answer · edited May 23 '14 at 15:10

The calculated column solution is probably the best one. But if you can't alter the data table's schema to add that, you can loop through the table and populate a new collection that will serve as the data source.

var dict = new Dictionary<Guid, string>();
foreach (DataRow row in dt.Rows)
{
    dict.Add(row["GUID"], row["Name"] + " " + row["Surname"]);
}
cbo.DataSource = dict;
cbo.DataTextField = "Value";
cbo.DataValueField = "Key";
cbo.DataBind();

Obviously this isn't as performant as binding directly to the DataTable but I wouldn't worry about that unless the table has thousands of rows.

score 19 · Answer 2 · answered Jun 17 '09 at 11:54

19

The easiest way is to create a new calculated column in the DataTable, using the Expression property :

tbldata.Columns.Add("FullName", typeof(string), "Name + ' ' + Surname");
...
cbo.DataTextField = "FullName";

answered Jun 17 '09 at 11:54

Thomas Levesque

286,951
70
623
758

1

I like this a lot better than the suggestions people keep making about modifying the data object and creating a new property. – TheTXI Jun 17 '09 at 12:10

score 5 · Answer 3 · answered Jun 17 '09 at 11:51

I would create a property on your data object then map that to the DataTextField

Data Object

public string FullName
{
  get { return Name + " " + Surname; }
}

Code-behind

cbo.DataSource = tbldata;
cbo.DataTextField = "FullName";
cbo.DataValueField = "GUID";
cbo.DataBind();

score 5 · Answer 4 · answered Dec 04 '09 at 09:21

5

Or implement 'Format' event like this:

DataRow r = ((DataRowView)e.ListItem).Row;
e.Value = r[ "FirstName" ] + " - " + r[ "LastName" ];

answered Dec 04 '09 at 09:21

anaconda

1,065
10
20

1

Most useful ! Thanks. – Konstantinos Chertouras Feb 29 '16 at 11:08
Where is the Format event? – Moon soon Feb 27 '20 at 02:36
@TangMonk, the Format event is in the ComboBox class. See here: [ComboBox](https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.combobox?view=netframework-4.8) – jlear Mar 04 '20 at 14:10

score 2 · Answer 5 · answered Jun 17 '09 at 11:53

2

Have a property in your class that is the concat of Name and Surname. And bind the DataTextField to this property.

In case you are binding it to a DataTable, you can add a new column to the DataTable whose values are concat of Name and Surname and bind it to the combo.

answered Jun 17 '09 at 11:53

Rashmi Pandit

23,230
17
71
111

i agree, can't think of another way – AlexDrenea Jun 17 '09 at 11:54
Since this is a simple one-use only, using a class as a base for this is overkill. – callisto Jun 17 '09 at 12:17

score 1 · Answer 6 · answered Jun 17 '09 at 11:54

1

Have a look at calculated columns using the Expression property of DataColumn.

answered Jun 17 '09 at 11:54

Ajw

716
3
8

score 0 · Answer 7 · answered Jun 17 '09 at 11:54

0

You can register the combo binding event and iterate the items, setting each item text to the desired fields using the combobox item data item.

answered Jun 17 '09 at 11:54

Tamir

3,833
3
32
41

How do I bind a ComboBox so the displaymember is concat of 2 fields of source datatable?

7 Answers7

Linked

Related