private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == NativeMethods.WM_COPYDATA)
{
NativeMethods.COPYDATASTRUCT copyData = (NativeMethods.COPYDATASTRUCT)Marshal.PtrToStructure(lParam, typeof(NativeMethods.COPYDATASTRUCT));
int dataType = (int)copyData.dwData;
if (dataType == 2)
{
string filename = Marshal.PtrToStringAnsi(copyData.lpData);
// Add the file name to the user control
AddEmlFile(filename);
}
else
{
MessageBox.Show("Unrecognized data type = " + dataType);
}
}
return(IntPtr.Zero);
}
private void Application_Startup(object sender, StartupEventArgs e)
{
if (e.Args.Length != 1)
{
MessageBox.Show("File name not specified." + Environment.NewLine + "Usage <executable> <emlfile>");
Environment.Exit(1);
}
var file = e.Args[0];
if (!File.Exists(file))
{
MessageBox.Show("File not found. " + Environment.NewLine + file);
Environment.Exit(2);
}
bool isNewInstance;
Mutex singleMutex = new Mutex(true, "MyAppMutex", out isNewInstance);
if (isNewInstance)
{
// Start the form with the file name as a parameter
var mainWindow = new MainWindow(file);
mainWindow.ShowDialog();
mainWindow.Close();
}
else
{
string windowTitle = "View Emls";
// Find the window with the name of the main form
IntPtr ptrWnd = NativeMethods.FindWindow(null, windowTitle);
if (ptrWnd == IntPtr.Zero)
{
MessageBox.Show("No window found with the title " + windowTitle);
}
else
{
IntPtr ptrCopyData = IntPtr.Zero;
try
{
// Create the data structure and fill with data
NativeMethods.COPYDATASTRUCT copyData = new NativeMethods.COPYDATASTRUCT();
copyData.dwData = new IntPtr(2); // Just a number to identify the data type
copyData.cbData = file.Length + 1; // One extra byte for the \0 character
copyData.lpData = Marshal.StringToHGlobalAnsi(file);
// Allocate memory for the data and copy
ptrCopyData = Marshal.AllocCoTaskMem(Marshal.SizeOf(copyData));
Marshal.StructureToPtr(copyData, ptrCopyData, false);
// Send the message
NativeMethods.SendMessage(ptrWnd, NativeMethods.WM_COPYDATA, IntPtr.Zero, ptrCopyData);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
finally
{
// Free the allocated memory after the contol has been returned
if (ptrCopyData != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(ptrCopyData);
}
}
}
Environment.Exit(1);
}
}