转换char []到System :: String ^（VC ++）的麻烦

Question

我正在尝试将char []转换为String ^，但我没有成功。转换仅返回用户名的第一个字符作为样本跟随MailMessage的属性主题^。有人能帮助我吗？非常感谢你。

     #include "windows.h"
        #include "Lmcons.h"
        #include "tchar.h"

        using namespace System::Net::Mail;


        void sendMail()
        {

        char username[UNLEN+1];
        DWORD username_len = UNLEN+1;
        GetUserName((LPWSTR)username, &username_len);

        String^ user = gcnew String(username);


        String^ email = L"mylogin@gmail.com";
        String^ to = L"recipient@live.com";
        String^ password = L"password";
        MailMessage^ message = gcnew MailMessage( email,to );
        message->Subject = user;
        message->Body = L"=================";
        message->Attachments->Add(gcnew Attachment("C:\\Windows\\client.txt"));
        SmtpClient^ client = gcnew SmtpClient( "smtp.gmail.com", 587 );
        client->UseDefaultCredentials = true;
        client->UseDefaultCredentials = false;
        client->Credentials = gcnew System::Net::NetworkCredential(email, password);
        client->EnableSsl = true;
        client->Send(message);
        client->~SmtpClient();

    }