Caption and Message only show the first letter when calling CredUIPromptForCredentials API

Question

I am creating a dialog asking for administrative credential by calling CredUIPromptForCredentials API. Here is a snippet of the code:

     int maxUserID = 100;
     int maxPassword = 100;
     int maxDomain = 100;
     StringBuilder userID = new StringBuilder(maxUserID);
     StringBuilder userPassword = new StringBuilder(maxPassword);
     StringBuilder userDomain = new StringBuilder(maxDomain);

     bool getCredential = false;

     // Setup the flags and variables         
     CREDUI_INFO credUI = new CREDUI_INFO();
     credUI.cbSize = Marshal.SizeOf(credUI);
     credUI.pszCaptionText = "Title";
     credUI.pszMessageText = "Please login as an administrator.";
     credUI.hwndParent = hwndParent;
     bool save = false;

     // for Windows XP
     if (IsWindowsXP)
     {            
        CREDUI_FLAGS flags = CREDUI_FLAGS.DO_NOT_PERSIST | CREDUI_FLAGS.REQUEST_ADMINISTRATOR;
        CredUIReturnCodes returnCode1;

        returnCode1 = PInvoke.CredUIPromptForCredentials(ref credUI, serverName, IntPtr.Zero, 0, userID, maxUserID, userPassword, maxPassword, ref save, flags);
        if (returnCode1 == CredUIReturnCodes.NO_ERROR)
        {
           getCredential = true;
        }
     } 

However, under Windows XP only the first letters of the Caption and Message appear, in my case, "T" and "P". And I cannot figure it out why? Any hints would be greatly appreciated!

Answer 1

Post your CREDUI_INFO declaration. It should look something like:

    struct CREDUI_INFO
    {
        public int cbSize;
        public IntPtr hwndParent;
        public string pszMessageText;
        public string pszCaptionText;
        public IntPtr hbmBanner;
    }