Question

private void treeView_ItemDrag(object sender, ItemDragEventArgs e)
{
    try
    {
        IVariable variable = getSelectedNode();
        this.treeView.DoDragDrop((Variable)variable, DragDropEffects.Copy);
    }
    catch (Exception)       {       }
}

private void splitContainer_Panel2_DragDrop(object sender, DragEventArgs e)
{

    Variable var = (Variable)(e.Data);
}

The Variable is a variable object (singleton pattern). I want this object dragged from a treeview to a other view (to draw the object).
I get this error code:

The object of type “System.Windows.Forms.DataObject” can not be converted to type ‘ORANGE_VARIABLE.Variable “.

I have the right Object inside the data.form.

How can I unwrap this object?

Answer 1

When you call DoDragDrop, your Variable object is automatically wrapped in a DataObject. To retrieve it, you need to call GetData with the type of the data you want to retrieve:

Variable var = (Variable)e.Data.GetData(typeof(Variable));