电子邮件代码运行两次，发送两次电子邮件

Question

我有这个简单的形式，我正在测试VS2012和vb.net。代码发送了两次电子邮件，我确实设置了断点，我不知道为什么它循环了两次。

代码:

Protected Sub btnSubmit_OnClick(sender As Object, e As EventArgs) Handles btnSubmit.Click
    Dim formBody As String
    formBody = "<b>Donation Amount: <b/>" + txtAmount.Text.Trim()
    Dim mailMessage As System.Net.Mail.MailMessage = New System.Net.Mail.MailMessage()
    mailMessage.From = New System.Net.Mail.MailAddress(System.Configuration.ConfigurationManager.AppSettings("fromEmailAddress"))
    mailMessage.To.Add(New System.Net.Mail.MailAddress("[e-mail]"))
    mailMessage.IsBodyHtml = True
    mailMessage.Subject = "Donation Form"
    mailMessage.Body = formBody
    Dim smtpClient As System.Net.Mail.SmtpClient = New System.Net.Mail.SmtpClient()
    smtpClient.Send(mailMessage)
    Response.Redirect("MemDonation_Confirmation.aspx", False)
End Sub

格式是:

<asp:Label runat="server" ID="lblAmount" Text="Donation Amount: "></Label>    
<asp:TextBox ID="txtAmount" runat="server"></asp:TextBox>
<asp:Button runat="server" ID="btnSubmit" OnClick="btnSubmit_OnClick" Text="Submit" style="height: 26px" /> 

Call Stack看起来是这样的，我不知道该怎么做:

Step into: Stepping over non-user code 'MemDonation.txtAmount.get'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.MailMessage'
Step into: Stepping over non-user  code 'System.Configuration.ConfigurationManager.AppSettings.get'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.To.get'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.IsBodyHtml.set'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.Subject.set'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.Body.set'
Step into: Stepping over non-user code 'System.Net.Mail.SmtpClient.SmtpClient'
Step into: Stepping over non-user code 'System.Net.Mail.SmtpClient.Send'
Step into: Stepping over non-user code 'System.Web.UI.Page.Response.get'
Step into: Stepping over non-user code 'MemDonation.txtAmount.get'
 Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.MailMessage'
Step into: Stepping over non-user code 'System.Configuration.ConfigurationManager.AppSettings.get'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.To.get'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.IsBodyHtml.set'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.Subject.set'
Step into: Stepping over non-user code 'System.Net.Mail.MailMessage.Body.set'
Step into: Stepping over non-user code 'System.Net.Mail.SmtpClient.SmtpClient'
Step into: Stepping over non-user code 'System.Net.Mail.SmtpClient.Send'
Step into: Stepping over non-user code 'System.Web.UI.Page.Response.get'
Step into: Stepping over non-user code 'System.Web.UI.WebControls.Button.OnClick'
Step into: Stepping over non-user code 'System.Web.UI.WebControls.Button.RaisePostBackEvent'
Step into: Stepping over non-user code 'System.Web.UI.Page.ProcessRequestMain'
 Step into: Stepping over non-user code 'ASP.memdonation_aspx.GetTypeHashCode'
Step into: Stepping over non-user code 'System.Web.UI.Page.SaveAllState'
Step into: Stepping over non-user code 'System.Web.UI.Page.ProcessRequestMain'
Step into: Stepping over non-user code 'System.Web.UI.Page.ProcessRequest'
Step into: Stepping over non-user code 'System.Web.UI.Page.ProcessRequest'
Step into: Stepping over non-user code 'ASP.memdonation_aspx.ProcessRequest'
Step into: Stepping over non-user code 'System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute'
Step into: Stepping over non-user code 'System.Web.HttpApplication.ExecuteStep'

Answer 1

您可以为btnSubmit.Click注册多个事件处理程序。函数中的Handles子句将自动为您创建一个。检查通过addhandler动态添加的任何其他处理程序