asp.net中的Gridview错误 [英] Gridview in asp.net Error

问题描述

嗨..

尝试执行gridview_rowupdatin()event
时，GridView中出现错误
错误:用户代码未处理NullReferenceException

对象引用未设置为对象的实例

我在这里干什么...?

 受保护的 子 GrdHRProcess_RowCommand( ByVal 发​​件人 As  对象， ByVal  e  As  System.Web.UI.WebControls.GridViewCommandEventArgs)句柄 GrdHRProcess.RowCommand

        Dim  MyConnection1  As  SqlConnection
        Dim  uid  As  字符串
       MyConnection1 = 新建 SqlConnection(ConfigurationManager.ConnectionStrings(" ).ConnectionString)
        Dim  sql1  As   String 
       sql1 = " 
        Dim  com  As  SqlCommand = 新建 SqlCommand( sql1，MyConnection1)
       com.Connection.Open()
       uid = Convert.ToString(com.ExecuteScalar)
       com.Connection.Close()

       uid = uid +  1 

        Dim  conn  As  新建 SqlConnection
       conn = 新建 SqlConnection(ConfigurationManager.ConnectionStrings(" ).ConnectionString)

       如果(e.CommandName.Equals(" ))然后



            Dim  txtNewName1  As  TextBox = GrdHRProcess.FooterRow.FindControl("  txtNewName")
            Dim  txtNewContact1  As  TextBox = GrdHRProcess.FooterRow.FindControl("  txtNewContact")
            Dim  txtNewCallDate1  As  TextBox = GrdHRProcess.FooterRow.FindControl("  txtNewCallDate")
            Dim  txtNewCallTime1  As  TextBox = GrdHRProcess.FooterRow.FindControl("  txtNewCallTime")
            Dim  txtNewStartDate1  As  TextBox = GrdHRProcess.FooterRow.FindControl("  txtNewSD")
            Dim  txtNewClass1  As  TextBox = GrdHRProcess.FooterRow.FindControl("  txtNewClass")
            Dim  ddlNewStatus1  As  DropDownList = GrdHRProcess.FooterRow.FindControl("  ddlNewStatus")
           conn.Open()
            Dim  cmd  As  新建 SqlCommand(" & uid& " & txtNewName1.Text& " & txtNewContact1.Text& " '，'"& txtNewCallDate1.Text&  '，'"& txtNewCallTime1.Text&  '，'"& ; txtNewStartDate1.Text& " & txtNewClass1.Text& " & ddlNewStatus1.Text& " ，conn)
           cmd.ExecuteNonQuery()

           conn.Close()

       结束 如果
   结束 子 

解决方案

该异常是不言自明的，NullReferenceException表示您正在尝试访问指向null的对象引用上的成员字段或函数类型.

希望对您有所帮助:)

有关更多查询，请在此处评论！！

Hi ..

i m getting Error in Gridview when i m trying to gridview_rowupdatin()event

error : NullReferenceException was Unhandled by user code

object reference not set to an instance of an object

What i m doing wreong here..?

Protected Sub GrdHRProcess_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles GrdHRProcess.RowCommand

       Dim MyConnection1 As SqlConnection
       Dim uid As String
       MyConnection1 = New SqlConnection(ConfigurationManager.ConnectionStrings("HRProcessConnectionString").ConnectionString)
       Dim sql1 As String
       sql1 = "select max(UDetailId) from HRProcess_Detail"
       Dim com As SqlCommand = New SqlCommand(sql1, MyConnection1)
       com.Connection.Open()
       uid = Convert.ToString(com.ExecuteScalar)
       com.Connection.Close()

       uid = uid + 1

       Dim conn As New SqlConnection
       conn = New SqlConnection(ConfigurationManager.ConnectionStrings("HRProcessConnectionString").ConnectionString)

       If (e.CommandName.Equals("AddNew")) Then



           Dim txtNewName1 As TextBox = GrdHRProcess.FooterRow.FindControl("txtNewName")
           Dim txtNewContact1 As TextBox = GrdHRProcess.FooterRow.FindControl("txtNewContact")
           Dim txtNewCallDate1 As TextBox = GrdHRProcess.FooterRow.FindControl("txtNewCallDate")
           Dim txtNewCallTime1 As TextBox = GrdHRProcess.FooterRow.FindControl("txtNewCallTime")
           Dim txtNewStartDate1 As TextBox = GrdHRProcess.FooterRow.FindControl("txtNewSD")
           Dim txtNewClass1 As TextBox = GrdHRProcess.FooterRow.FindControl("txtNewClass")
           Dim ddlNewStatus1 As DropDownList = GrdHRProcess.FooterRow.FindControl("ddlNewStatus")
           conn.Open()
           Dim cmd As New SqlCommand("Insert into HRProcess_Detail(UDetailId,CandidateName,ContactNo,CallDate,CallTime,StartDate,Class,Status) values('" & uid & "','" & txtNewName1.Text & "','" & txtNewContact1.Text & "','" & txtNewCallDate1.Text & "', '" & txtNewCallTime1.Text & "','" & txtNewStartDate1.Text & "', '" & txtNewClass1.Text & "','" & ddlNewStatus1.Text & "')", conn)
           cmd.ExecuteNonQuery()

           conn.Close()

       End If
   End Sub

解决方案

the exception is self explanatory, NullReferenceException refers that you are trying to access member fields or function types on an object reference that points to null.

hope it helps :)

for further queries comment here!!

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