Get Component's Parent Form

Question

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

Answer 1

I found this solution which does not need the input. For C# I implemented it this way:

public partial class RegistryManager : Component, ISupportInitialize
{

    private Form _parentForm;
    public Form ParentForm
    {
        get { return _parentForm;  }
        set { _parentForm = value; }
    }

    // Etc....

    #region ISupportInitialize
    public void BeginInit() {  }
    public void EndInit()
    {
        setUpParentForm();
    }
    private void setUpParentForm()
    {
        if (_parentForm != null) return; // do nothing if it is set
        IDesignerHost host;
        if (Site != null)
        {
            host = Site.GetService(typeof(IDesignerHost)) as IDesignerHost;
            if (host != null)
            {
                if (host.RootComponent is Form)
                {
                    _parentForm = (Form)host.RootComponent;
                }
            }
        }
    }
    #endregion
}

This way allows the set ParentForm by user, but it is set by parent form as Default.

I hope it helps you.

Answer 2

Try This ....

private Form GetParentForm(Control parent)
{
    if (parent is Form)
        return parent as Form;

    return parent.FindForm();
}

Call GetParentForm(this.Parent) from component

Answer 3

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.

Answer 4

You will have to set the parent container some how. Your component is just a class, that resides in memory just like everything else. It has no true context of what created it unless something tells you that it did. Create a Parent control property and set it.

Or simply derive from control and use FindForm(). Not all controls must have a visible component

Answer 5

Thanks Rob, I used your solution in a VB.Net program, looks like this:

''' <summary>
''' Returns the parent System.Windows.form of the control
''' </summary>
''' <param name="parent"></param>
''' <returns>First parent form or null if no parent found</returns>
''' <remarks></remarks>
Public Shared Function GetParentForm(ByVal parent As Control) As Form
    Dim form As Form = TryCast(parent, Form)
    If form IsNot Nothing Then
        Return form
    End If

    If parent IsNot Nothing Then
        ' Walk up the control hierarchy
        Return GetParentForm(parent.Parent)
    End If

    ' Control is not on a Form
    Return Nothing
End Function

Referenced it on my blog: http://www.dailycode.info/Blog/post/2012/07/03/How-to-get-a-user-controls-parent-form-(Windows-forms).aspx

Answer 6

I think you want to use the Site property of the IComponent. It's more or less an equivalent to the Parent property.