ASP.NET 錯誤處理

ASP.NET錯誤處理一般有三種處理方式：

1　在頁面級錯誤事件中，在單獨頁面中的錯誤。可以在page_error事件中添加處理邏輯，具體如下：

protected void Page_Error(object sender, EventArgs e)
{
    string ErrString = string.Empty;
    Exception objErr = Server.GetLastError().GetBaseException();
    ErrString += DateTime.Now.ToString() + "<br/>";
    ErrString += "<b>Error Caught in Page_Error event</b><hr><br>" +
            "<br><b>Error in: </b>" + Request.Url.ToString() +
            "<br><b>Error Message: </b>" + objErr.Message.ToString() +
            "<br><b>Stack Trace:</b><br>" + objErr.StackTrace.ToString();
    Server.ClearError();
    Response.Write(ErrString);
}

protected void Button1_Click(object sender, EventArgs e)
{
    int result;
    try
    {
        result = Convert.ToInt32(TextBox1.Text) / Convert.ToInt32(TextBox2.Text);
        Response.Write(result.ToString());
    }
    catch(Exception ex)
    {
        //Response.Write(ex.ToString());
        throw;
    }
}

2      在應用程式級的錯誤事件中，在應用程式中的錯誤。可以在global.asax檔中的application_error中添加處理  邏輯，具體如下：

Sub Application_Error()Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
 ' 在發生錯誤時激發
        Dim err As String = "<h1>Application Error</h1>" _
                            & "Error in:" _
                            & Request.Url.ToString & "</p>" _
                            & "Stack Trace Below:</br>" _
                            & Server.GetLastError.ToString
        Response.Write(err)
        Server.ClearError()
    End Sub

3     在應用程式設定檔中，為應用程式執行的聲明性錯誤處理，具體如下：

＜system.web>
<customErrors defaultRedirect="url" mode="RemoteOnly">
        <error statusCode="code" redirect="url"></error>
        </customErrors>
＜/system.web>

當頁面發生錯誤時，應用程式也應該讓管理員或開發人員知道何時何地出現了錯誤，一般有兩種方法。

1    向Event Log 寫入事件

Imports System.Diagnostics

Sub Application_Error()Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
        ' 在發生錯誤時激發
        Dim PageUrl As String = Request.Path
        Dim ErrorInfo As Exception = Server.GetLastError()

        Dim Message As String = "Url:" & PageUrl & "</br>"
        Message = Message & " Error: "
        Message = Message & ErrorInfo.ToString & "</br>"

        Dim LogName As String = "MyCustomLog"
        If (Not EventLog.SourceExists(LogName)) Then
            EventLog.CreateEventSource(LogName, LogName)
        End If

        Dim Log As New EventLog
        Log.Source = LogName
        Log.WriteEntry(Message, EventLogEntryType.Error)
    End Sub

2    發送Email

Sub Application_Error()Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
        ' 在發生錯誤時激發
        Dim PageUrl As String = Request.Path
        Dim ErrorInfo As Exception = Server.GetLastError()

        Dim Message As String = "Url:" & PageUrl & "</br>"
        Message = Message & " Error: "
        Message = Message & ErrorInfo.ToString & "</br>"

        Dim Mymessage As New MailMessage
        Mymessage.To = "tianhao960@gmail.com"
        Mymessage.From = "tianhao960@gmail.com"
        Mymessage.Subject = "ASP.NET Error"
        Mymessage.BodyFormat = MailFormat.Text

        Mymessage.Body = Message
        SmtpMail.Send(Mymessage)
    End Sub