Question

I’m trying to use a MonthCalendar Control that uses winforms, in a simple WPF application. I found out that by using a WindowsFormsHost, winforms controls can be used in wpf apps. It worked for the built-in controls of winforms, but when I try to instantiate an object of this control MonthCalendar, I get an error saying “Cannot instantiate an object of MonthCalendar”.

Any suggestions as to why this is happening and how to overcome this?
The source code for MonthCalendar is available at http://www.codeproject.com/Articles/10840/Another-Month-Calendar?msg=2298161#xx2298161xx

Im instantiating it in xaml:

<Window x:Class="MonthCalendarTest.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:wf="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
    xmlns:pc="clr-namespace:Pabo.Calendar"
    Title="MainWindow" Height="350" Width="525">
<Grid Height="65" Width="280">

    <WindowsFormsHost Margin="0,0,12,12" Height="100">
        <pc:MonthCalendar></pc:MonthCalendar>

    </WindowsFormsHost>
</Grid>

Answer 1

I can get it to work by following these steps:

• using Visual Studio 2010
• create new WPF Application
• change platform to “.Net Framework 4” (NOT client profile)

• add references to System.Windows.Forms and WindowsFormIntegration

• download MonthCalendar from:
  http://www.codeproject.com/KB/selection/MonthCalendar/MonthCalendar_src_vs2005.zip

• extract MonthCalendar, and add as existing project to Solution
• change MonthCalendar platform to “.Net Framework 4” (NOT client profile)
• delete and re-add the System.Design reference so that you use the .NET 4 one
• in the WPF Application add reference to the MonthCalendar project
• use the namespace reference xmlns:pc=”clr-namespace:Pabo.Calendar;assembly=MonthCalendar” in XAML

<Window x:Class="WpfApplication6.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:wf="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
        xmlns:pc="clr-namespace:Pabo.Calendar;assembly=MonthCalendar"
    Title="MainWindow" Height="350" Width="525">
    <Grid Height="65" Width="280">
        <WindowsFormsHost Margin="0,0,12,12" Height="100">
            <pc:MonthCalendar x:Name="myCalendar"/>
        </WindowsFormsHost>
    </Grid>
</Window>

So what are you doing differently?

Did you keep the MonthCalendar in it’s own project?

What OS platform are you running on ?