[c#] How to SELECT a dropdown list item by value programmatically

How to SELECT a drop down list item by value programatically in C#.NET?

ddl.SetSelectedValue("2");

With a handy extension:

public static class WebExtensions
{

    /// <summary>
    /// Selects the item in the list control that contains the specified value, if it exists.
    /// </summary>
    /// <param name="dropDownList"></param>
    /// <param name="selectedValue">The value of the item in the list control to select</param>
    /// <returns>Returns true if the value exists in the list control, false otherwise</returns>
    public static Boolean SetSelectedValue(this DropDownList dropDownList, String selectedValue)
    {
        ListItem selectedListItem = dropDownList.Items.FindByValue(selectedValue);

        if (selectedListItem != null)
        {
            selectedListItem.Selected = true;
            return true;
        }
        else
            return false;
    }
}

Note: Any code is released into the public domain. No attribution required.

combobox1.SelectedValue = x;

I suspect you may want yo hear something else, but this is what you asked for.

Please try below:

myDropDown.SelectedIndex = 
myDropDown.Items.IndexOf(myDropDown.Items.FindByValue("myValue"))

For those who come here by search (because this thread is over 3 years old):

string entry // replace with search value

if (comboBox.Items.Contains(entry))
   comboBox.SelectedIndex = comboBox.Items.IndexOf(entry);
else
   comboBox.SelectedIndex = 0;

This is a simple way to select an option from a dropdownlist based on a string val

private void SetDDLs(DropDownList d,string val)
    {
        ListItem li;
        for (int i = 0; i < d.Items.Count; i++)
        {
            li = d.Items[i];
            if (li.Value == val)
            {
                d.SelectedIndex = i;
                break;
            }
        }
    }

ddlPageSize.Items.FindByValue("25").Selected = true;

If anyone else is trying this and facing problem then let me point one possible problem: If you are using Web Application then inside Page_Load if you are loading drop-down from DB and at the sametime you want to load data, then first load your drop-down lists and then load your data with selected drop-down conditions.

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        LoadDropdown(); //drop-downs generated first
        LoadData(); // other data loading and drop-down value selection logic here
    }
}

And for successfully selecting drop-down from code follow the approved answer above which is

ddl.SelectedValue = "2";.

Hope it solves the problem

Ian Boyd (above) had a great answer -- Add this to Ian Boyd's class "WebExtensions" to select an item in a dropdownlist based on text:

/// <summary>
/// Selects the item in the list control that contains the specified text, if it exists.
/// </summary>
/// <param name="dropDownList"></param>
/// <param name="selectedText">The text of the item in the list control to select</param>
/// <returns>Returns true if the value exists in the list control, false otherwise</returns>
public static Boolean SetSelectedText(this DropDownList dropDownList, String selectedText)
{
    ListItem selectedListItem = dropDownList.Items.FindByText(selectedText);
    if (selectedListItem != null)
    {
        selectedListItem.Selected = true;
        return true;
    }
    else
        return false;
}

To call it:

WebExtensions.SetSelectedText(MyDropDownList, "MyValue");

I prefer

if(ddl.Items.FindByValue(string) != null)
{
    ddl.Items.FindByValue(string).Selected = true;
}

Replace ddl with the dropdownlist ID and string with your string variable name or value.