Error after Adding WPF on VB.Net

[k3nnt0ter0]

I embedded the WPF to vb.net and I got some error.
1. There's still a green underline on line

Me.SampleUserControl1 = New SampleWpfUserControlLibrary.SampleUserControl()

but that's nothing I guess since the underline was green.
2. My very problem is on the line

_hostWindow.OpenDocument();

says

Object reference not set to an instance of an object.

My guess is that, it was suppose to be hosted on a Window but in my project's case, it was hosted on an Elementhost


Here's the code :

using System;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;


namespace SampleWpfUserControlLibrary
{
    /// <summary>
    /// Interaction logic for SampleUserControl.xaml
    /// </summary>
    public partial class SampleUserControl
    {
        private IApplicationHostWindow _hostWindow;
        
        [Obsolete("This constructor should not be used", false)]
        public SampleUserControl()
        {
            InitializeComponent();
        }


        public SampleUserControl(IApplicationHostWindow applicationHostWindow)
        {
            _hostWindow = applicationHostWindow;


            I****TestVisible = true;


            InitializeComponent();
        }


        public double GetViewboxWidth()
        {
            return viewHost.ActualWidth;
        }


        public double GetViewboxHeight()
        {
            return viewHost.ActualHeight;
        }


        public void SetViewboxChild(UIElement child)
        {
            viewHost.Content = child;
        }


        public void ProcessLeftButtonDown(Point point)
        {
            var result = VisualTreeHelper.HitTest(this, point);
            return;
        }


        protected override HitTestResult HitTestCore(PointHitTestParameters hitTestParameters)
        {
            return base.HitTestCore(hitTestParameters) ??
                   new PointHitTestResult(viewHost.Content as Visual ?? viewHost, hitTestParameters.HitPoint);
        }


        private void exitMenuItem_Click(object sender, RoutedEventArgs e)
        {
            _hostWindow.Exit();
        }


        private void newProjectMenuItem_Click(object sender, RoutedEventArgs e)
        {
             _hostWindow.OpenDocument();
        }


        private void UserControl_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            return;
        }


        private void UserControl_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            return;
        }
    }
}

 

[JohnH]

My guess is that, it was suppose to be hosted on a Window but in my project's case, it was hosted on an Elementhost

IApplicationHostWindow interface is not from WPF or anywhere in .Net framework libraries, it has probably something to do with your library.

 

[k3nnt0ter0]

IApplicationHostWindow interface is not from WPF or anywhere in .Net framework libraries, it has probably something to do with your library.

Any clue what to do about that something in my library?

It works fine if I run the WPF only. I get error when I add it on the VB Project. .

 

[k3nnt0ter0]

Anyone? Here are some related code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace SampleWpfUserControlLibrary
{
    public interface IApplicationHostWindow
    {
        void OpenDocument();
        void Exit();
    }
}

It is from the C++ File

[COLOR=blue][FONT=Consolas]using[/FONT][/COLOR][COLOR=blue][FONT=Consolas]namespace[/FONT][/COLOR][COLOR=black][FONT=Consolas] SampleWpfUserControlLibrary;[/FONT][/COLOR]
 [COLOR=blue]ref[/COLOR] [COLOR=blue]class[/COLOR] ApplicationHostWrapper : IApplicationHostWindow
{
[COLOR=blue]public[/COLOR]:    ApplicationHostWrapper(CMainFrame * pMainFrame)    
{        _pMainFrame = pMainFrame;    
}       
[COLOR=blue]virtual[/COLOR] [COLOR=blue]void[/COLOR] __clrcall Exit() [COLOR=blue]sealed[/COLOR]   
 {       
 _pMainFrame->SendMessage(WM_CLOSE);    
}     
[COLOR=blue]virtual[/COLOR] [COLOR=blue]void[/COLOR] __clrcall OpenDocument() [COLOR=blue]sealed[/COLOR]   
 {        _pMainFrame->OpenDocument();    
} [COLOR=blue]private[/COLOR]:    CMainFrame * _pMainFrame;
};

 

[JohnH]

This is probably what you should have posted first: Embedding PowerPoint presentation player into a WPF application - CodeProject
The problem with that is that the sample is actually hosting a WPF user control in a MFC application. The WPF usercontrol itself does not appear it can be used in neither WPF environment nor by ElementHost in winforms environment.

 

[k3nnt0ter0]

Is that so?
But according to the goal stated on that link

1. Create a reusable component (ActiveX) in C++ using MFC which could later be embedded into a .NET-base application;

I guess it will be reusable. .

 

[JohnH]

That was the first of three options author considered, and you can read that option was abandoned.

 

[k3nnt0ter0]

I missed that one. Anyway, can I at least make it at the top most of the form? I mean It will not be brought back if I pressed somehow click or did something on the form behind it?

 

[annaharris]

IapplicationHostWindow doesn't seem to be from WPF library, I think it's from C++ library.