C# 如何獲取彈出消息框的計數？

Question

我正在制作一個批量郵件發件人，它將從數據庫中獲取郵件地址。 一切正常，測試郵件正在發送，但只有在所有郵件發送后才會顯示成功消息。 我想要一個消息框或一個進度框來計算通過的郵件。 幫我添加一個消息排場來計算已發送的郵件。 這里是我用於發送郵件的代碼，請給我寫消息框的代碼以顯示計數 -

private void btnSendEmail_Click(object sender, EventArgs e){
string subject = txtSubject.Text;
string message = txtMessage.Text;            
if (!txtFile.Text.Equals(String.Empty))
{
    if (System.IO.Directory.GetFiles(txtFile.Text).Length > 0)
    {
        foreach (string file in System.IO.Directory.GetFiles(txtFile.Text))
        {
        }
    }
    else
    {
    }
}

var con = "Data Source=Ashiq-pc;Initial Catalog=OfferMails;Integrated Security=True;MultipleActiveResultSets=True";
List<EmailModel> emailList = new List<EmailModel>();
using (SqlConnection myConnection = new SqlConnection(con))
{
    string oString = "Select * from tbl_MailAdd where Flag=@Flag";
    SqlCommand oCmd = new SqlCommand(oString, myConnection);
    oCmd.Parameters.AddWithValue("@Flag", true);     
    myConnection.Open();
    using (SqlDataReader oReader = oCmd.ExecuteReader())
    {
        while (oReader.Read())
        {
            EmailModel emailModel = new EmailModel();
            emailModel.ID = Convert.ToInt16(oReader["ID"]);
            emailModel.EmailAdd = oReader["EmailAdd"].ToString();
            emailModel.Flag = Convert.ToBoolean(oReader["Flag"]);
            emailList.Add(emailModel);                 
        }

        myConnection.Close();
    }               
}

//return matchingPerson;
foreach (EmailModel email in emailList)
{
    try
    {
        SmtpClient client = new SmtpClient("smtp.gmail.com");
        client.Port = 587;
        client.EnableSsl = true;
        client.Timeout = 100000;
        client.DeliveryMethod = SmtpDeliveryMethod.Network;
        client.UseDefaultCredentials = false;
        client.Credentials = new NetworkCredential("my mail", "my pass");
        MailMessage msg = new MailMessage();
        msg.To.Add(email.EmailAdd);
        msg.From = new MailAddress("my from name");
        msg.Subject = subject;
        msg.Body = message;
        if (!txtFile.Text.Equals(String.Empty))
        {
            if (System.IO.Directory.GetFiles(txtFile.Text).Length > 0)
            {
                foreach (string file in System.IO.Directory.GetFiles(txtFile.Text))
                {
                    //Add file in ListBox.
                    listAttch.Items.Add(file);
                    //System.Windows.Forms.MessageBox.Show("Files found: " + file, "Message");
                    Attachment data = new Attachment(file);
                    msg.Attachments.Add(data);
                }
            }
            else
            {
                //listBox1.Items.Add(String.Format(“No files Found at location : {0}”, textBox1.Text));
            }
        }
        //Attachment data = new Attachment(textBox_Attachment.Text);
        //msg.Attachments.Add(data);
        client.Send(msg);
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

//for (int i = 0; i < emailList.Count; i++)
//{
//    MessageBox.Show("i++");
//}

MessageBox.Show("Successfully Sent Message.");

}

Answer 1

首先，我只想說，在這里要求某人為您編寫此代碼有點令人不快。 但我知道你在問什么，所以我願意幫忙。

首先，消息框本身不會為此工作，因為消息框最終會停止線程，直到處理DialogResult事件。 因此，話雖如此，您可能想要構建另一個表單（我假設您在此處使用 Windows 表單執行此操作。）來為您完成進度。 如果您希望它是一個計數器，那么您可以使用一個標簽來實現，該標簽在每封郵件發送時都會更改其文本。

因此，話雖如此，但是，如果您使用 Windows 窗體執行此操作，您將遇到的問題是該窗體在您的foreach循環完成之前永遠不會更新。 這是因為 C# 處理線程使用的方式。

對於您想要完成的工作，您需要使用BackgroundWorker. 這允許您異步運行繁瑣的操作。

以下是您可以用來讓系統正常工作的示例：

//used to be a counter for your progress
int i_counter = 0;

//create  a background worker instance
public BackgroundWorker bg_worker = new BackgroundWorker();



public Form1()
{
    InitializeComponent();
    //set this to true if you want to have an event where you can cancel the background task
    bg_worker.WorkerSupportsCancellation = true;
    //this is needed to actually show your progress, allows the background worker to report it is working
    bg_worker.WorkerReportsProgress = true;

    //assigns the "DoWork" and "ProgressChanged" Handlers to the background worker.
    bg_worker.DoWork += new DoWorkEventHandler(bg_worker_DoWork);
    bg_worker.ProgressChanged += new ProgressChangedEventHandler(bg_worker_ProgressChanged);
}

//Mail method
public void MailerMethod()
{
    //all of the things you want to happen for your mailing methods

    foreach(//your loop stuff in here)
    {
        //THIS NEEDS TO HAPPEN TO CAUSE THE COUNTER TO UPDATE
        bg_worker.ReportProgress(i_counter);
    }

}



//the stuff that you want done in the background
//fires when "RunAsync" is called by BackgroundWorker object.
private void bg_worker_DoWork(object sender, DoWorkEventArgs e)
{

    //IN HERE IS WHERE YOU WANT YOUR EMAIL STUFF TO HAPPEN
    bg_worker = sender as BackgroundWorker;
    MailerMethod();//or just all of your mailing code, it looks nicer like this though

}

//fires when worker reports the progress has changed
//caused by "ReportProgress" method
private void bg_worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    lb_counter.Text = Convert.ToString(i_counter);
}

  //this is what will happen when the worker is done.
  //you can have it do a alot of things, such as write a report, show a window, etc.
private void bg_worker_RunWorkComplete(object sender, RunWorkerCompletedEventArgs e)
{
    MessageBox.Show("DONE!", "DING DING!");
    Application.Exit();

}


//button click event to start this shindig
private void bt_start_Click(object sender, EventArgs e)
{
    //makes sure the background worker isn't already trying to run
    if (!bg_worker.IsBusy)
    {
        //calls the DoWork event
        bg_worker.RunWorkerAsync();
        bt_start.Visible = false;
    }
}

我可以指導您到這里獲取官方 MDSN 文檔嗎？ 這里有一個關於如何設置BackgroundWorker的基本教程。

希望這會有所幫助，讓我知道它是怎么回事。

Answer 2

使用進度條，其 Position 屬性設置為零，Max 屬性設置為您發送的電子郵件數量，Step 屬性設置為 1，除非您想每 10 封左右的電子郵件步進一次，否則您將在循環中使用 % 10以提高進度。 在您的循環中，只需增加 ProgresBar 的位置或調用 Step()。