Add new row on a grid bound to an object which does not have a parameterless constructor

[Andrea]

Hello, i have this, were working using microsoft grid, how can i make it work with the winforms grid?

When i try to add a new row raise an exception like 'System.MissingMethodException' no parameterless constructor.

[Serializable]
public class ScheduledMovement : NotifyPropertyChanged
{
    //various props
    public excMovements Movements
      {get;set;}
    //other
}

public class excMovements :
  BindingList<ScheduledMovementDetail>, IBindingList
{
  protected override object AddNewCore()
  {
      ScheduledMovementDetail n = new ScheduledMovementDetail(parent);
      Add(n);
      return n;
   }
}

[Dimitar]

Hi Andrea,

Thank you for writing.

I have tested with similar structure, but there is no exception on my side. I have attached my test project. Could you please let me know what I need to change in order to reproduce the exception.

I am looking forward to your reply.

Regards,
Dimitar
Telerik by Progress

[Andrea]

Hi, using your project i can generate the exceptio with this modification: add a constructor with a parameter

 

class MyList : BindingList<ChildData>, IBindingList
   {
       protected override object AddNewCore()
       {
           ChildData item = new ChildData(0);
           item.ChildText = "test";
           Add(item);
           return item;
       }
   }
   class ChildData
   {
       public ChildData(int x)
       { }
       public string ChildText { get; set; }
   }

that's it.

when you try to add a new row on the child template, the exception is generatd.

 

[Dimitar]

Hi Andrea,

Thank you for writing back.

In this case, the parameterless constructor is required by our implementation. We use it to create a new instance of the class and populate the data according to the data in the columns. So in order to be able to add new rows you need to add a parameterless constructor as well. 

I hope that you find this information useful. 

Regards,
Dimitar
Telerik by Progress

[Andrea]

Ok thanks.  It is possible in any way to use an external factory to let the grid create the instance or to have an event to capture to let me create the object using the newRowInfo as parameter?

 

 

[Dimitar]

Hello Andrea,

Thank you for writing.

You can use the UserAddingRow event to cancel the adding operation and then manually add new row directly to your data source. For example:

private void RadGridView1_UserAddingRow(object sender, GridViewRowCancelEventArgs e)
{
    if (e.Rows[0].ViewTemplate == radGridView1.MasterTemplate.Templates[0])
    {
        e.Cancel = true;
        radGridView1.CurrentRow = null;
        var item = data[0].Data.AddNew();

    }
}

Please let me know if there is something else I can help you with. 

 

Regards,
Dimitar
Telerik by Progress