MVC - Set selected value of SelectList

Question

How can I set the selectedvalue property of a SelectList after it was instantiated without a selectedvalue;

SelectList selectList = new SelectList(items, \"I         


        

Answer 1

In case someone is looking I reposted my answer from: SelectListItem selected = true not working in view

After searching myself for answer to this problem - I had some hints along the way but this is the resulting solution for me. It is an extension Method. I am using MVC 5 C# 4.52 is the target. The code below sets the Selection to the First Item in the List because that is what I needed, you might desire simply to pass a string and skip enumerating - but I also wanted to make sure I had something returned to my SelectList from the DB)

Extension Method:

public static class SelectListextensions {

public static System.Web.Mvc.SelectList SetSelectedValue

(this System.Web.Mvc.SelectList list, string value) { if (value != null) { var selected = list.Where(x => x.Text == value).FirstOrDefault(); selected.Selected = true;
} return list; }
}

And for those who like the complete low down (like me) here is the usage. The object Category has a field defined as Name - this is the field that will show up as Text in the drop down. You can see that test for the Text property in the code above.

Example Code:

SelectList categorylist = new SelectList(dbContext.Categories, "Id", "Name");

SetSelectedItemValue(categorylist);

select list function:

private SelectList SetSelectedItemValue(SelectList source) { Category category = new Category();

SelectListItem firstItem = new SelectListItem();

int selectListCount = -1;

if (source != null && source.Items != null)
{
    System.Collections.IEnumerator cenum = source.Items.GetEnumerator();

    while (cenum.MoveNext())
    {
        if (selectListCount == -1)
        {
            selectListCount = 0;
        }

        selectListCount += 1;

        category = (Category)cenum.Current;

        source.SetSelectedValue(category.Name);

        break;
    }
    if (selectListCount > 0)
    {
        foreach (SelectListItem item in source.Items)
        {
            if (item.Value == cenum.Current.ToString())
            {
                item.Selected = true;

                break;
            }
        }
    }
}
return source;

}

You can make this a Generic All Inclusive function / Extension - but it is working as is for me