개체 참조가 개체의 인스턴스로 설정되지 않았습니다.

Question

서버에 웹을 배포 할 때 왜이 오류가 발생하는지 알 수 없습니다. 연결 문자열에 문제가 있기 때문입니까? 도와주세요. 고맙습니다!!!

의 Web.config

<add name="Database1" connectionString="Data Source='170.21.191.85';Initial Catalog='Database1';User ID='sa';Password='123'"/> 

Login.aspx.vb

Dim connection As String = System.Configuration.ConfigurationManager.ConnectionStrings("Database1").ConnectionString() 
    Dim mycon As New SqlConnection(connection) 

스택 추적

[NullReferenceException이 :. 개체의 인스턴스로 설정되지 않은 개체 참조] C : \ Users \ L30810 \ Desktop \ fyp fina의 WebApplication1.Login.ImageButton2_Click (Object sender, ImageClickEventArgs e) (ImageEventArgs) +86 System.Web.UI.WebControls.ImageButton.RaisePostBackEvent (String eventArgument) +115 System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent (문자열 eventArgument) +7 System.Web.UI.Page.RaisePostBackEvent (IPostBackEventHandler sourceControl, 문자열 eventArgument) +11 System.Web.UI .Page.RaisePostBackEvent (NameValueCollection은 postData를) +33 System.Web.UI.Page.ProcessRequestMain (부울 includeStagesBeforeAsyncPoint 부울 includeStagesAfterAsyncPoint) 1,746

ImageButton2_ 클릭

Protected Sub ImageButton2_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles ImageButton2.Click 
    Dim connection As String = System.Configuration.ConfigurationManager.ConnectionStrings("Database1").ConnectionString() 
    Dim mycon As New SqlConnection(connection) 

    mycon.Open() 

    Dim queryString As String = "SELECT Role,StaffName FROM [role] WHERE LoginID ='" + TextBox1.Text + "' and Password='" + TextBox2.Text + "'" 
    Dim cmd As SqlCommand = New SqlCommand(queryString, mycon) 

    Dim reader As SqlDataReader = cmd.ExecuteReader() 

    Dim user1 As String = "" 
    While reader.Read() 
     Dim role As String = "" 
     role = reader.GetString(0) 
     user1 = reader.GetString(1) 
     Session("role") = role 
    End While 

    If (Session("role") = "SA") Then 
     Response.Expires = 0 
     Response.ExpiresAbsolute = Now() 
     Response.CacheControl = "no-cache" 
     Session("User") = user1 
     Response.Redirect("MainPageSA.aspx") 

    ElseIf (Session("role") = "MGR") Then 
     Session("User") = user1 
     Response.Expires = 0 
     Response.ExpiresAbsolute = Now() 
     Response.CacheControl = "no-cache" 
     Response.Redirect("MainPageMGR.aspx") 

    ElseIf (Session("role") = "Assessor") Then 
     Session("User") = user1 
     Response.Expires = 0 
     Response.ExpiresAbsolute = Now() 
     Response.CacheControl = "no-cache" 

     Response.Redirect("MainPageAssessor.aspx") 

    ElseIf (Session("role") = "MC") Then 
     Session("User") = user1 
     Response.Expires = 0 
     Response.ExpiresAbsolute = Now() 
     Response.CacheControl = "no-cache" 
     Response.Redirect("MainPageMC.aspx") 
    Else 
     MsgBox("Invalid Username/Password", MsgBoxStyle.OkOnly, "Clinical Peformance Appraisal") 

    End If 
    reader.Close() 
    mycon.Close() 
End Sub 

Answer 1

연결 문자열의 값을 따옴표로 묶을 필요는 없습니다.

<add name="Database1" connectionString="Data Source=170.21.191.85;Initial Catalog=Database1;User ID=sa;Password=final"/>