Question

i used vb.net before and want to explore c#. (they said c# is better than vb.net) but anyways… i used this code below from vb.net calling controls in parent window.

Dim strWindowToLookFor As String = GetType(MainWindowForm).Name
Me.Close()
Dim win = (From w In Application.Current.Windows Where DirectCast(w, Window).GetType.Name = strWindowToLookFor Select w).FirstOrDefault
If win IsNot Nothing Then
    DirectCast(win, MainWindowForm).imglogin.Visibility = Windows.Visibility.Visible
    DirectCast(win, MainWindowForm).Focus()
End If

i found this code before in other forums and helps me a lot in vb.net… but now i want to use this code in c# for me to call controls… so i converted it using SharpDevelop ( a good software)….

        string strWindowToLookFor = typeof(MainWindowForm).Name;
        this.Close();
        var win = (from w in Application.Current.Windowswhere ((Window)w).GetType().Name == strWindowToLookForw).FirstOrDefault;
        if (win != null) {
            ((MainWindowForm)win).imglogin.Visibility = System.Windows.Visibility.Visible;
            ((MainWindowForm)win).Focus();
        }

the problem is it gives me an error:

Error 1 Could not find an implementation of the query pattern for source type ‘System.Windows.WindowCollection’. ‘Where’ not found. Consider explicitly specifying the type of the range variable ‘w’.

Error #1 highlighted the Application.Current.Windows.

Error 2 A query body must end with a select clause or a group clause

Answer 1

I don’t think you really need to use reflection here. You could try something much simpler:

var mainWindow = Application.Current.Windows.OfType<MainWindowForm>()
                                            .FirstOrDefault();

if (mainWindow != null)
{
   //Visibility stuff goes here
}