C# bring unassociated app to foreground

Question

I've been searching all over the net for answers to get a program to the foreground. I've been doing it the ghetto way by sending alt-tab keystrokes with SendKeys. I've tried this and it doesn't work,

private void execute()
{
    setApp("League of Legends.exe");
    Thread.Sleep(1500);
}

[DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr hWnd);
private static void setApp(String filename)
{
    Process[] SameProcesses = Process.GetProcessesByName(filename);
    Process SameProcess = SameProcesses[0];
    if (SameProcess.Equals(null))
    {
        System.Windows.Forms.MessageBox.Show("No process");
    }
    else
    { 
        SetForegroundWindow(SameProcess.MainWindowHandle); 
    }
}