How to change orderby on postback for LINQ to SQL query

I have a drop down list set to auto post back which needs to return a list of products in the specified order. I thought I could just put that query in its own method and use a parameter to specify the orderby, but I cannot get it to work.

Here is an example:

protected void Show_Products(int item)
    {
      开发者_StackOverflow社区  using (storeDataContext db = new storeDataContext())
        {
           string query = "";
            switch (item)
            {
                case 1:
                    query ="x.Name";
                    break;
                case 2:
                    query = "x.MSRP";
                    break;
                default:
                    break;
            }
            var q = db.Items.OrderBy(x=> query).Select(x => x);
            foreach(var n in q)
             {
               Do work
             }
           }
       }

And the drop down list method that gets called on postback:

protected void ddlSortBy_SelectedIndexChanged(object sender, EventArgs e)
    {
        int value =int.Parse(ddlSortBy.SelectedValue);
        Show_Products(value);
    }

---

var q = from p in db.Items
        select q;

switch(item)
{
    case 1:
        q.OrderBy(x=> x.Name);
        break;
    case 2:
        q.OrderBy(x=> x.MSRP);
        break;
    default:
        break;

}

foreach(var n in q)
{
    // Do work
}

---

I took one look at that book of code someone linked and knew there was a way to do it. Low and behold I was right.

protected void Show_Products(int item)
{
    using (storeDataContext db = new storeDataContext())
    {
       var q = db.Items.OrderBy(x=> x.Name).Select(x => x);
        switch (item)
        {
            case 1:
                var q = db.Items.OrderBy(x=> x.Name).Select(x => x);
                break;
            case 2:
                q = db.Items.OrderBy(x => x.MSRP).Select(x => x);
                break;
            default:
                break;
        }

        foreach(var n in q)
         {
           Do work
         }
       }
   }

I initially set var q to a query for initialization, but it doesn't matter because this method will be passed a parameter which will change it.

It may not be the most elegant way, but for only a few options I think it is doable.

---

Sorry, but what you are trying to do is using a Literal "x.Name" and "x.MSRP" to access methods.. you don't do it unless you are using Reflection to get Method and Properties.