Question

这是我的申请摘要：我使用Windows窗体在c＃中创建了这个应用程序，一切顺利，直到我添加了一个登录表单（带有2个电子邮件和密码的文本框），这允许我使用任何电子邮件登录...所以任何人都可以使用此应用程序发送电子邮件。因此，首先会显示一个登录表单，我需要输入我的电子邮件和密码，按下“登录”按钮后，我的主表单将会显示。

这是我的代码：

登录表格代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using SendEmail.Classes;
namespace SendEmail
{
    public partial class Login : Form
    {
        public static string tb1;
        public static string tb2;

        public Login()
        {
            InitializeComponent();
            textBoxPassword.PasswordChar = '*';
        }

        private void btnLogin_Click(object sender, EventArgs e)
        {
            Form1 form1 = new Form1();
            tb1 = textBoxEmail.Text;
            tb2 = textBoxPassword.Text;
            if (textBoxEmail != null && textBoxPassword != null)
            {
                //I use email and pass to take string values and put them into my main form, where I need to specify user's username and password
                form1.email = tb1; 
                form1.pass = tb2;
                form1.Show();
            }
        }
    }
}

Form1的代码（主要表格）：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net.Mail;
using System.Text.RegularExpressions;
using SendEmail.Classes;

namespace SendEmail
{
    public partial class Form1 : DevExpress.XtraEditors.XtraForm 
    {
        User user = new User();
        public string email;
        public string pass;
        public Form1()
        {
            InitializeComponent();
            DevExpress.Skins.SkinManager.EnableFormSkins();
        }
        private void btnSend_Click(object sender, EventArgs e)
        {
            try
            {
                //Error reports
                #region Error Reports
                Regex RX = new Regex("^[a-zA-Z0-9]{1,20}@[a-zA-Z0-9]{1,20}.[a-zA-Z]{2,3}$");
                if (!RX.IsMatch(textBoxTo.Text))
                {
                    errorProviderEmail.SetError(textBoxTo, "Email format is not correct");
                    return;
                }
                if (textBoxSubject.Text == string.Empty)
                {
                    errorProviderEmail.SetError(textBoxSubject, "Enter a subject");
                    return;
                }
                #endregion

                MailMessage mail = new MailMessage();
                SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com", 587);
                //System.Net.NetworkCredential auth = new System.Net.NetworkCredential();
                mail.From = new MailAddress(email);
                mail.To.Add(textBoxTo.Text);
                mail.Subject = textBoxSubject.Text;
                mail.Body = richText.Text;

                SmtpServer.Credentials = new System.Net.NetworkCredential(\*here I need the text from textBoxEmail (Login form) :*/ email, \*here I need the text from textBoxPassword (Login form) */ pass);
                SmtpServer.EnableSsl = true;

                #region Attachments
                Attachment data = new Attachment(textBoxAttachment.Text);
                Attachment data2 = new Attachment(textBoxAttachment2.Text);
                Attachment data3 = new Attachment(textBoxAttachment3.Text);
                mail.Attachments.Add(data);
                mail.Attachments.Add(data2);
                mail.Attachments.Add(data3);
                #endregion

                SmtpServer.Send(mail);
                MessageBox.Show("mail Send");
                Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

        private void textBoxTo_TextChanged(object sender, EventArgs e)
        {
            errorProviderEmail.Clear();
        }

        private void textBoxSubject_TextChanged(object sender, EventArgs e)
        {
            errorProviderEmail.Clear();
        }

        private void buttonUpload_Click(object sender, EventArgs e)
        {
            OpenFileDialog dlg = new OpenFileDialog();
            if (dlg.ShowDialog() == DialogResult.OK)
            {
                textBoxAttachment.Text = dlg.FileName.ToString();
            }
        }

        private void buttonUpload2_Click(object sender, EventArgs e)
        {
            OpenFileDialog dlg = new OpenFileDialog();
            if (dlg.ShowDialog() == DialogResult.OK)
            {
                textBoxAttachment2.Text = dlg.FileName.ToString();
            }
        }

        private void buttonAttachment3_Click(object sender, EventArgs e)
        {
            OpenFileDialog dlg = new OpenFileDialog();
            if (dlg.ShowDialog() == DialogResult.OK)
            {
                textBoxAttachment3.Text = dlg.FileName.ToString();
            }
        }
    }

问题在于，当我进行调试时，它会抛出异常：“参数'fileName'不能是空字符串”，所以我认为我的电子邮件字符串没有从textBoxEmail中获取文本。

我希望我已经明确指出了我的问题：D如果我可以使用我的程序插入图片会更容易。

Answer 1

我将假设其中一个Attachments fileName是空字符串，因此抛出此异常。

        if(!string.IsNullOrEmpty(textBoxAttachment.Text.Trim()))
        {
            Attachment data = new Attachment(textBoxAttachment.Text.Trim());
            mail.Attachments.Add(data);
        }
        if(!string.IsNullOrEmpty(textBoxAttachment2.Text.Trim()))
        {
            Attachment data = new Attachment(textBoxAttachment2.Text.Trim());
            mail.Attachments.Add(data);
        }
        if(!string.IsNullOrEmpty(textBoxAttachment3.Text.Trim()))
        {
            Attachment data = new Attachment(textBoxAttachment3.Text.Trim());
            mail.Attachments.Add(data);
        }

这应解决问题。

使用SMTP在Gmail上发送电子邮件

1 个答案: