Problem trying to get a datatable from an IList or an IQuery

g_r_a_robinson@hotmail.co · **Joined:** Sat Sep 17, 2005 5:48 am **Posts:** 9

I saw another post in this forum demonstrating how to create a datatable from either Ilist or IQuery but I cant seem to get it to work and I am wondering if the code is wrong. I am desperate to get this working. Heres the code

Code:

public class TypedListGenerator { 
   public TypedListGenerator(IList nestedArrays) { 
      this._nestedArrays = nestedArrays; 
      this._view = new DataTable(); 
   } 
    
   IList _nestedArrays; 
   DataTable _view; 
    
   public void AddColumn(string name) { 
      this.AddColumn(name, typeof(String)); 
   } 
    
   public void AddColumn(string name, Type type) { 
      this._view.Columns.Add(name, type); 
   } 
    
   public ITypedList Format() { 
      if(this._view.Rows.Count != this._nestedArrays.Count) { 
         foreach(object[] row in this._nestedArrays) { 
            this._view.Rows.Add(row); 
         } 
      } 
       
      return this._view.DefaultView; 
   }    
}

The code breaks on the line:

foreach(object[] row in this._nestedArrays)

with the error :

specified cast is not valid.

I cant see why, I realise this might be more of a .net problem but I'm not sure.

Thanks

KPixel · **Posted:** Sat Oct 08, 2005 7:29 am

_nestedArrays doesn't contains object[], you need to find the type of the elements in _nestedArrays and use it (it is either an entity, an IList or a simple field).

g_r_a_robinson@hotmail.co · **Joined:** Sat Sep 17, 2005 5:48 am **Posts:** 9

I hate to have to ask, but how could i find out?

Thanks again

KPixel · **Posted:** Wed Oct 12, 2005 2:04 pm

As I said, it is either an entity, an IList or a simple field; so, you can write something like:

Code:

if( o is IList) ...
else if( o is ...) ...

I think that System.Type has a IsValue() or something like that to know if it is a "simple field".
For IList, you probably need to do a recursive call...