如何在vb.net发送电子邮件时使用进度条？

Question

如何在发送电子邮件的同时在vb.net中添加进度条？

Answer 1

就在您调用SmtpClient.SendAsync（）之前，将ProgressBar.Visible属性设置为True。在SmtpClient.SendCompleted事件的事件处理程序中将其设置为False。 PB必须将其Style属性设置为“选取框”。

您不能以其他方式给出准确的进度信息，StmpClient和MailMessage类都没有一个事件告诉您工作完成了多少。

Answer 2

您可以使用计时器控件并使进度条在处理程序中移动。当达到最大值时，您可以将进度条重置为零。这不会反映实际的进度，但它会让用户看到并显示应用程序未被锁定。

Answer 3

只是把这个代码，您SMPT客户端代码每个步骤之后和每个步骤后增加值，

progressbar1.value = 10 

下面代码可以帮助你..

包含： 3文本框（TB_subject， TB_name，TB_cmt） 1个按钮（btn_submit） 1个进度条（Progressbar1） 和 3个标签。

例如： -

代码：

Imports System.Net.Mail 
____________________________________________________________________ 
Public Class Form1 

Private Sub btn_submit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_submit.Click 
If TB_Name.Text = "" Or TB_Subject.Text = "" Or TB_Cmt.Text = "" Then 
MsgBox("Name, Subject and Comment are required fields", vbCritical, "Error") 

Else 



Try 
Dim Mail As New MailMessage 
progressbar1.value = 10   'note that the value is "10" 

Mail.From = New MailAddress("youremail@gmail") 
progressbar1.value = 20      'now its "20" 

Mail.To.Add("youremail@gmail.com") 
progressbar1.value = 30      '"30" and its increases..... 

Mail.Subject = TB_Subject.Text & " - " & TB_Name.Text 
progressbar1.value = 40 

Mail.Body = TB_Cmt.Text 
progressbar1.value = 50 

Dim smtp As New SmtpClient("smtp.gmail.com") 
progressbar1.value = 60 

smtp.Port = 587 
progressbar1.value = 70 

smtp.EnableSsl = True 
progressbar1.value = 80 

smtp.Credentials = New System.Net.NetworkCredential("YOUR GMAIL USERNAME ID HERE", "YOUR GMAIL PASSWORD HERE") 
progressbar1.value = 90 

smtp.Send(Mail) 
progressbar1.value = 100 


MsgBox("Sent Successfully", vbInformation, "Thank you") 
progressbar1.value = 0     'Reset Progress Bar. 

Catch ex As Exception 
MsgBox("There was an error, the program will close now!!", vbCritical, "Fatal error") 
End Try 
End If 
End Sub