C# convert object array into datatable

Hello everyone,

I failed to find a sample about how to convert an array instances of user defined types into a (C# ADO.Net) datatable -- I want to use the datatable to bind to ASP.Net data bound controls (e.g. gridview). Could anyone provide a sample or recommend me to some simple samples?

Another question is, whether it is a must to convert to datatable in order to bound to controls in ASP.Net? Could I bound to any array of user defined types?

thanks in advance, George

From stackoverflow

• No, you don't need a DataTable to do binding - in fact, most binding now is object based, especially with LINQ (which generates an object model, not a DataTable). Just use the public property names (from your class) as the data-members for different columns, etc.

  George2 : Hi Marc, glad to see you here. :-) Sorry I can not use LINQ for non-technical reasons. Are there any other solutions for me if not using DataTable/DataSet?

• I would suggest using the ObjectDataSource class to do what you want. Then you won't need to use a DataTable at all, and you'll still be able to get data binding. ObjectDataSource allows you to expose user defined types to data binding, and it doesn't matter how the types are obtained; they don't need to come from a database at all, if that's what you need.

  George2 : I read the link you recommended. Currently, my application is 3 tiers, ASP.Net -- Web Service -- Database. In the sample of the link, ASP.Net queries data source directly which violates my design purpose to make Web Service layer in the middle to transparent data access. Comments or better samples?

  Sean Reilly : Is the example you're referring to the one that references EmployeeLogic? If so, change the implementation of the GetAllEmployees() method to call the Web Service instead using a SqlDataSource. ObjectDataSource works with any kind of object, so you can obtain the data from anywhere you need to.

• I had the same requirement and I found a nice article at Pauls Blog. You can have a look at the following link if you still wanted it

  http://weblogs.asp.net/psperanza/archive/2005/05/18/407389.aspx

  Here is the code that I have used in my project. Hope that helps

  Public Function ConvertArrayToDatatable(ByVal arrList As ArrayList) As DataTable
              Dim dt As New DataTable
              Try
                  If arrList.Count > 0 Then
                      Dim arrype As Type = arrList(0).GetType()
                      dt = New DataTable(arrype.Name)
  
                      For Each propInfo As PropertyInfo In arrype.GetProperties()
                          dt.Columns.Add(New DataColumn(propInfo.Name))
                      Next
  
                      For Each obj As Object In arrList
                          Dim dr As DataRow = dt.NewRow()
  
                          For Each dc As DataColumn In dt.Columns
                              dr(dc.ColumnName) = obj.GetType().GetProperty(dc.ColumnName).GetValue(obj, Nothing)
                          Next
                          dt.Rows.Add(dr)
  
                      Next
                  End If
  
  
                  Return dt
              Catch ex As Exception
                  Return dt
              End Try
  
          End Function
  

• In regards to the comment "can not use LINQ for non-technical reasons":

  I presume you don't want to use LINQ to SQL since you want to maintain your three-tiered architecture. But you may not know that you can use LINQ to Objects and that would provide the flexibility you seek.

  Suppose you have a middle tier method: List Tier2.SomeMethod(). You can assign that return value of that method as the GridView data source and then specify SomeObject methods/properties in the GridView control: gvSomeGridView.DatasSource = Tier2.SomeMethod(); gvSomeGridView.DataBind();

  Further you can then retrieve SomeObject from the DataItem in GridView callbacks.

  HTH.