Question

I have a custom built menu system in which I would like to load user controls from another project into a tab control on my main project (menu control)

User control Project : foobar
Menu system Project : Menu

The function to load them into the tab control:

private void LaunchWPFApplication(string header, string pPath)
        {
            // Header - What loads in the tabs header portion.
            // pPath   - Page where to send the user

            //Create a new browser tab object
            BrowserTab bt = tabMain.SelectedItem as BrowserTab;
            bt = new BrowserTab();
            bt.txtHeader.Text = header;
            bt.myParent = BrowserTabs;

             //Load in the path 
        try
        {
            Type formType = Type.GetType(pPath, true);
            bt.Content = (UserControl)Activator.CreateInstance(formType);
        }
        catch
        {
            MessageBox.Show("The specified user control : " + pPath + " cannot be found");
        }

            //Add the browser tab and then focus            
            BrowserTabs.Add(bt);
            bt.IsSelected = true;
        }

And what I send to the function as an example:

LaunchWPFApplication("Calculater", "foobar.AppCalculater");

But every time run, the application complains that the formType is null. I am confused on how to load the user control and curious if I’m sending the correct parameters.

Answer 1

The problem I had was in calling the Type.GetType. The generic call which the MSDN gives is

Type formType = Type.GetType("AppCalculater");

which calls get the type of the specified name. This would still no matter what return a null. I then added the namespace to the mix.

Type formType = Type.GetType("foobar.AppCalculater");

This however was still giving me an error calling the other project files in foobar. To get the user controls in the other project, I added the assembly after the control and namespace call.

Type formType = Type.GetType("foobar.AppCalculater,foobar");

I then was able to reference all the user controls dynamically using this call. Thus my now updated call to load a user control from another project into my tab control is as follows :

private void LaunchWPFApplication(string header, string pPath)
        {
            // Header - What loads in the tabs top portion.
            // Path   - Page where to send the user

            //Create a new browser tab object
            BrowserTab bt = tabMain.SelectedItem as BrowserTab;
            bt = new BrowserTab();
            bt.txtHeader.Text = header;
            bt.myParent = BrowserTabs;

            //Load in the path 
            try
            {
                Type formType = Type.GetType(pPath); //Example "foobar.foobarUserControl,foobar"
                bt.Content = Activator.CreateInstance(formType);
            }
            catch (ArgumentNullException)
            {
                MessageBox.Show("The specified user control : " + pPath + " cannot be found");
            }
            catch (Exception ex)
            {
                MessageBox.Show("An error has occurred while loaded the specified user control : " + pPath + ". It includes the following message : \n" + ex);
            }
            //Add the browser tab and then focus     
            try
            {
                BrowserTabs.Add(bt);
            }
            catch(InvalidOperationException)
            {
                MessageBox.Show("Cannot add " + pPath + " into the tab control");
            }
            bt.IsSelected = true;
        }