private void btnCancel_Click(object sender, EventArgs e)
 {
     if (this.AfterInputCredential != null)
     {
         EmailCredentialEventArgs arg = new EmailCredentialEventArgs(string.Empty, string.Empty, string.Empty, true);
         this.AfterInputCredential(this, arg);
     }
     this.Close();
 }
 void frmCred_AfterInputCredential(object sender, EmailCredentialEventArgs args)
 {
     if (args.Cancel)
         return;
     this.SenderEmail = args.UserID;
     this.SenderPassword = args.Password;
     this.CC = args.CC;
     this.validated_cc.Clear();
     //處理寄件備份
     string[] ccs = this.CC.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
     foreach (string cc in ccs)
     {
         if (cc.Trim().Length > 0)
             this.validated_cc.Add(cc);
     }
 }
        private void btnOK_Click(object sender, EventArgs e)
        {
            bool isOk = true ;

            //Validate UserID
            if (string.IsNullOrWhiteSpace(this.txtUserID.Text))
            {
                this.errorProvider1.SetError(this.txtUserID, "請輸入帳號。");
                isOk = false;
            }
            else
            {
                if (!this.isValidEmail(this.txtUserID.Text.Trim()))
                {
                    this.errorProvider1.SetError(this.txtUserID, string.Format("帳號『{0}』是不正確的電子郵件格式。", this.txtUserID.Text));
                    isOk = false;
                }
                else
                    this.errorProvider1.SetError(this.txtUserID, "");
            }

            //  驗證副本是否符合電子郵件格式
            string[] ccs = this.txtCC.Text.Trim().Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
            List<string> err_emails = new List<string>();
            foreach (string cc in ccs)
            {
                if (cc.Trim().Length > 0)
                {
                    if (!this.isValidEmail(cc))
                        err_emails.Add(cc);
                }
            }
            if (err_emails.Count > 0)
            {
                this.errorProvider1.SetError(this.txtCC, string.Format("寄信副本『{0}』是不正確的電子郵件格式。", string.Join(",", err_emails)));
                isOk = false;
            }
            else
                this.errorProvider1.SetError(this.txtCC, "");

            if (isOk)
            {
                //Validate Password
                if (string.IsNullOrWhiteSpace(this.txtPassword.Text))
                {
                    if (MessageBox.Show("確定密碼是空白嗎?", "注意", MessageBoxButtons.YesNo, MessageBoxIcon.Information) != System.Windows.Forms.DialogResult.Yes)
                    {
                        isOk = false;
                    }
                }
            }

            if (isOk)
            {
                if (this.AfterInputCredential != null)
                {
                    EmailCredentialEventArgs arg = new EmailCredentialEventArgs(this.txtUserID.Text, this.txtPassword.Text, this.txtCC.Text);
                    this.AfterInputCredential(this, arg);
                }
                this.Close();
            }
        }