IWindowsFormsEditorService delay after closing

Question

I need to have a custom property value editor integrated into PropertyGrid control. Code is listed below

internal class VariableTypeEditor : UITypeEditor
{
    public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
    {
        return UITypeEditorEditStyle.DropDown;
    }

    public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
    {
        IWindowsFormsEditorService service = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;

        Type type = context.GetType();
        PropertyInfo property = type.GetProperty("OwnerGrid");

        IPlugIn plug = context.Instance as IPlugIn;

        if (service != null && property != null
                            && plug != null)
        {
            PropertyGrid owner = property.GetValue(context) as PropertyGrid;

            if (owner != null)
            {
                Collection<VariableWrapper> variables = owner.Tag as Collection<VariableWrapper>;

                if (variables != null)
                {
                    VariableEditorForm editor = new VariableEditorForm();
                    editor.Value = plug.VariableName;
                    editor.Variables = variables.Select(o => o.Variable).Where(o => o.ValueType == plug.VariableType).ToArray();
                    editor.TopLevel = false;
                    editor.FormClosed += new FormClosedEventHandler((sender, args) =>
                    {
                        service.CloseDropDown();
                    });

                    service.DropDownControl(editor);
                    value = editor.Value;
                }
            }
        }

        return value;
    }
}

I want it to work this way:

• to change value of the property user opens up the DropDown with VariableEditorForm (using PropertyGrid)
• user selects one of the values listed in the VariableEditorForm and after that VariableEditorForm would close automatically

It works now. But for some reason it takes 2-3 seconds before EditValue method would return its value.

Why service.DropDownControl(editor) does not return immediately after its closing?

Answer 1

Is it possible to have value of const : WM_DISABLE_RENDER and WM_ENABLE_RENDER