急救!!120...VB.NET问题

[fayewang]

imports system.data
imports system.data.sqlclient
imports system.nullreferenceexception
public class _default
inherits system.web.ui.page
# region "web 窗体设计器
...简了
dim mycon as sqlconnection
dim mycom as sqlcommand
sub page_load(sender as object,e as eventargs)
if not ispostback then
mycon=new sqlconnection("data source=(local);initial catalog=lyzygl;user id=sa;")
mycom=new sqlcommand("select name,passwd from ydzy",mycon)
end if
end sub
sub button1_click(sender as object,e as eventargs)
mycon.open()
dim dt as SqlDataReader=mycom.ExcuteReader()
while dt.read()
if trim(dt("name"))=trim(textbox1.text) and trim(dt("passwd"))=trim(textbox2.text) then
reponse.redirect("announce.aspx")
end if
dt.read()
end while
message.html="用户不存在或者密码错误!"
end sub
......以下简了....
错误信息为:未将对象引用设置到对象的实例/////
不要叫我换成 datatable...因为我换了也不行!我的程序里每个页面全是这种错误我已经倒了。!!!!谢谢告诉我。。。。。

[hychieftain]

密码没有输入，是执行哪条语句报错的？
mycon=new sqlconnection("data source=(local);initial catalog=lyzygl;user id=sa;pwd=密码;")

[fayewang]

我同学都说这个论坛好，说只要发出的问题一会5分钟就有人给你回话，。。我都等了10分钟了，哎，不会我真的这么惨吧没有有理我。。!~!~!~

[fayewang]

呵呵谢谢正在看。。

[fayewang]

dim dt as sqldatareader=mycom.excutereader()

[ljmay168]

mycon=new sqlconnection("data source=(local);initial catalog=lyzygl;user id=sa;")
mycom=new sqlcommand("select name,passwd from ydzy",mycon)
這兩句要放在if not ispostback then ... end if的外面
我一般都在聲明的同時賦值.

[fayewang]

我去试一试,,,wait for me ...

[fayewang]

Imports System.Data
Imports System.Data.SqlClient
Imports System.Web
Imports System.IO
Public Class register
Inherits System.Web.UI.Page

#Region " Web 窗体设计器生成的代码 "

'该调用是 Web 窗体设计器所必需的。
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

End Sub
Protected WithEvents usid As System.Web.UI.WebControls.TextBox
Protected WithEvents Button1 As System.Web.UI.WebControls.Button
Protected WithEvents message As System.Web.UI.HtmlControls.HtmlGenericControl
Protected WithEvents RequiredFieldValidator2 As System.Web.UI.WebControls.RequiredFieldValidator
Protected WithEvents RequiredFieldValidator1 As System.Web.UI.WebControls.RequiredFieldValidator
Protected WithEvents ValidationSummary1 As System.Web.UI.WebControls.ValidationSummary
Protected WithEvents pwd As System.Web.UI.WebControls.TextBox
Protected WithEvents pwd1 As System.Web.UI.WebControls.TextBox
Protected WithEvents part As System.Web.UI.WebControls.TextBox
Protected WithEvents usertype As System.Web.UI.WebControls.DropDownList
Protected WithEvents RequiredFieldValidator3 As System.Web.UI.WebControls.RequiredFieldValidator
'注意: 以下占位符声明是 Web 窗体设计器所必需的。
'不要删除或移动它。
Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
'CODEGEN: 此方法调用是 Web 窗体设计器所必需的
'不要使用代码编辑器修改它。
InitializeComponent()
End Sub

#End Region
Dim cou As Integer
Dim mycon As SqlConnection = New SqlConnection("data source=wangfei;initial catalog=lyzygl;user id=sa;")
Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'在此处放置初始化页的用户代码
End Sub

Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim insertcmd As String = "insert into usertype (name,passwd,type,depart) values (@name,@passwd,@type,@depart)"
Dim mycom As SqlCommand = New SqlCommand(insertcmd, mycon)
mycom.Parameters.Add(New SqlParameter("@name", SqlDbType.NVarChar, 50))
mycom.Parameters.Add(New SqlParameter("@passwd", SqlDbType.NVarChar, 50))
mycom.Parameters.Add(New SqlParameter("@type", SqlDbType.Int, 4))
mycom.Parameters.Add(New SqlParameter("@depart", SqlDbType.NVarChar, 50))
mycom.Parameters("@name").Value = usid.Text
mycom.Parameters("@passwd").Value = pwd.Text
mycom.Parameters("@type").Value = 3
mycom.Parameters("@depart").Value = part.Text
mycom.Connection.Open()
Try
If pwd.Text = pwd1.Text Then
mycom.ExecuteNonQuery()
message.InnerHtml = "恭喜你,注册成功!"
mycom.Connection.Close()
Response.Redirect("default.aspx")
Else
message.InnerHtml = "你的密码与确认密码不一致!"
End If
Catch exp As SqlException
message.InnerHtml = "发生异常!请重新输入!"
End Try
End Sub
End Class
运行时又报错了...
错误如下:
“/lyzygl”应用程序中的服务器错误。
--------------------------------------------------------------------------------

未将对象引用设置到对象的实例。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。

源错误:


行 55： If pwd.Text = pwd1.Text Then
行 56： mycom.ExecuteNonQuery()
行 57： message.InnerHtml = "恭喜你,注册成功!"
行 58： mycom.Connection.Close()
行 59： Response.Redirect("default.aspx")


源文件: c:\inetpub\wwwroot\lyzygl\register.aspx.vb 行: 57

堆栈跟踪:


[NullReferenceException: 未将对象引用设置到对象的实例。]
lyzygl.register.Button1_Click(Object sender, EventArgs e) in c:\inetpub\wwwroot\lyzygl\register.aspx.vb:57
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +108
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +58
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain() +1277

[ljmay168]

Dim mycom As SqlCommand = New SqlCommand(insertcmd, mycon)
mycom.CommandType = CommandType.StoredProcedure