Converting to an int in LINQ not working?

The following query complains that the int conversion is not supported.

var list = from d in data
           where d.Id == (int)GridView1.DataKeys[0].Value
           select d;

It complains on the (int)GridView1.SelectedInex line telling me that the Int conversion is not supported. I also tried Convert.ToInt32, but that did not work either.

Is this logic that has to be calculated before such as above the linq query or is there a special way to do it and if not, why does it 开发者_StackOverflow中文版not support it?

Why not try and parse the value to an integer before hand, it's not needed in the query.

Int id;
if (Int32.TryParse(ridView1.DataKeys[0].Value.ToString(), out id))
{
    var list = from d in data
               where d.Id == id
               select d;
}

I assume the semicolon after the where line is a typo?

Pull the cast outside the linq query, it's trying to generate SQL for the cast operation, which isn't supported

int id = (int)GridView1.DataKeys[0].Value;
var list = from d in data
           where d.Id = id
           select d;

you are casting, not converting.

int.Parse( GridView1.DataKeys[0].Value ) 

would be converting.

GridView1.DataKeys[0].Value returns an object which may or may not be an int.

I'm guessing here, but try:

where d.Id == (int)(GridView1.DataKeys[0].Value);

in case it's trying to cast the GridView.

(edit: fixed code - see comment on question)

This answer is wrong!