Get Component's Parent Form
I have a non-visual component which manages other visual controls.
I need to have a reference to the form that the component is operating on, but i don't know how to get it.
I am unsure of adding a constructor with the parent specified as control, as i want the component to work by just being dropped into the designer.
The other thought i had was to have a Property of parent as a control, with the default value as 'Me'
any suggestions would be great
Edit:
To clarify, this is a component, not a control, see here :ComponentModel.Component
[It is important to understand that the ISite technique below only works at design time. Because ContainerControl is public and gets assigned a value VisualStudio will write initialization code that sets it at run-time. Site is set at run-time, but you can't get ContainerControl from it]
Here's an article that describes how to do it for a non-visual component.
Basically you need to add a property ContainerControl to your component:
public ContainerControl ContainerControl
{
get { return _containerControl; }
set { _containerControl = value; }
}
private ContainerControl _containerControl = null;
and override the Site property:
public override ISite Site
{
get { return base.Site; }
set
{
base.Site = value;
if (value == null)
{
return;
}
IDesignerHost host = value.GetService(
typeof(IDesignerHost)) as IDesignerHost;
if (host != null)
{
IComponent componentHost = host.RootComponent;
if (componentHost is ContainerControl)
{
ContainerControl = componentHost as ContainerControl;
}
}
}
}
If you do this, the ContainerControl will be initialized to reference the containing form by the designer. The linked article explains it in more detail.
A good way to see how to do things is to look at the implementation of Types in the .NET Framework that have behaviour similar to what you want with a tool such as Lutz Reflector. In this case, System.Windows.Forms.ErrorProvider is a good example to look at: a Component that needs to know its containing Form.
I use a recursive call to walk up the control chain. Add this to your control.
public Form ParentForm
{
get { return GetParentForm( this.Parent ); }
}
private Form GetParentForm( Control parent )
{
Form form = parent as Form;
if ( form != null )
{
return form;
}
if ( parent != null )
{
// Walk up the control hierarchy
return GetParentForm( parent.Parent );
}
return null; // Control is not on a Form
}
Edit: I see you modified your question as I was typing this. If it is a component, the constructor of that component should take it's parent as a parameter and the parent should pass in this when constructed. Several other components do this such as the timer.
Save the parent control as a member and then use it in the ParentForm property I gave you above instead of this.