Question

I’m trying to filter a datatable with following code

private void Filter(string text)
    {
        int outText=0;
        if (Int32.TryParse(text, out outText))
        {
            text = string.Empty;
        }
     DataTable DT = new DataTable();
            DT = PinCDAO.GetArea().AsEnumerable().Where(r => r.Field<int>("AreaID")==Convert.ToInt32(outText) || (r.Field<string>("AreaDescription").Contains(text))).AsDataView().ToTable();

}

I’m getting the error “Specified cast is not valid”.because of the code

r => r.Field<int>("AreaID")==Convert.ToInt32(outText) 

I’m sure about that AreaID column Contains Integers

plz help me to solve this.

Answer 1

Try out code – Handle null in you code

because “AreaID” is nullable field.

DT = PinCDAO.GetArea().AsEnumerable().Where(r => 
   (Convert.IsDBNull(r["AreaID"]) ? 0 :  Convert.ToInt32(r["AreaID"])) ==outText
  || (r.Field<string>("AreaDescription").Contains(text))).AsDataView().ToTable();

this code handles null value easily..

already answered question by me : "Specified cast is not valid" error in LINQ's orderby clause