CODEWITHSUNDEEP
c#.netcomboboxcompact-framework
Mark
Mark

Reputation: 179

Selecting a value in combobox that's populated from a DataTable

I have a combobox being populated by a DataTable as shown below. I want to be able to set which item is shown. The value it is to be set to is a string that will be found in the "Id" column.

public DataTable list = new DataTable();
public ComboBox cbRates = new ComboBox();

//prepare rates combo data source
this.list.Columns.Add(new DataColumn("Display", typeof(string)));
this.list.Columns.Add(new DataColumn("Id", typeof(string)));

//populate the rates combo
int counter = 0;

foreach (string item in dropdownItems)
{
    this.list.Rows.Add(list.NewRow());
    if (counter == 0)
    {
    this.list.Rows[counter][0] = "Select Rate..";
    this.list.Rows[counter][1] = "";
}
else
{
string[] itemSplit = item.Split('`');
if (itemSplit.Length == 2)
{
    this.list.Rows[counter]["Display"] = itemSplit[0];
    this.list.Rows[counter]["Id"] = itemSplit[1];
}
else
{
    this.list.Rows[counter]["Display"] = item;
    this.list.Rows[counter]["Id"] = item;
}
}
counter++;
}
this.cbRates.DataSource = list;
this.cbRates.DisplayMember = "Display";
this.cbRates.ValueMember = "Id";

//now.. how to set the selected value?

int rowCount = 0;
foreach (DataRow cbrow in this.list.Rows)
{
    if (DB.GetString(cbrow["Id"]) == answerSplit[1])
    {
        //attempting to set the SelectedIndex throws an exception
        //on another combobox populated NOT from a DataTable - this does work fine.
        this.cbRates.SelectedIndex = rowCount;
    }
    rowCount++;
}

//this doesn't seem to do anything.
foreach (DataRow dr in this.list.Rows)
{
    if ((string)dr["Id"] == answerSplit[1]) this.cbRates.SelectedItem = dr;
}

//nor this
foreach(DataRow dr in this.cbRates.Items)
{
   try
   {
     if ((string)dr["Id"] == answerSplit[1]) this.cbRates.SelectedItem = dr;
   }
    catch
    {
      MessageBox.Show("Ooops");
    }
}

Without FindExactString, FindString, FindByValue being not present in compact framework I am running out of things to try.

If attempt to use

this.cbRates.SelectedIndex = 2;

I get the following error;

System.Exception: Exception
at Microsoft.AGL.Common.MISC.HandleAr(PAL_ERROR ar)
at System.Windows.Forms.ComboBox.set_SelectedIndex(Int32 value)

However, if I put the relevant code into it's own form for testing purposes I can set the selectedIndex without error.

I think these issues are linked.

Upvotes: 3

Views: 10362

Answers (4)

Avishka Dambawinna
Avishka Dambawinna

Reputation: 1215

You can set SelectedIndex by finding the item that exactly matches the specified string ComboBox.FindStringExact Method

cbRates.SelectedIndex = cbRates.FindStringExact("Value_need_to_Select") ;

Upvotes: 0

Szörényi Ádám
Szörényi Ádám

Reputation: 1263

You can do this, it's working but not too fast if you have tons of items:

foreach (object item in comboBox1.Items)
{
    DataRowView row = item as DataRowView;
    if ((String)row["YourDisplayMemberColumn"] == "ValueYouWantToSelect")
    {
        comboBox1.SelectedItem = item;
    }
}

Upvotes: 1

Morten
Morten

Reputation: 3854

Are you aware that you can use the datatable directly as datasource? 

        cbo.DataSource = table;
        cbo.DisplayMember = "Display";
        cbo.ValueMember = "Id";

Upvotes: 4

26071986
26071986

Reputation: 2330

Did you try to set SelectedValue? You have an Id, and you state that ValueMember is Id, then use it.

Upvotes: 2

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