hi there,
i need help in my vb behind codes. There is an error at these part 'con.Open()'. When i run the code the error says, "The ConnectionString property has not been initialized.". It also says , "invalid operationsException was unhandled by user code."

Imports System.Data.Sql
Imports System.Data.SqlClient
Imports System.Web
Partial Class _Default
    Inherits System.Web.UI.Page
    Dim str As String = ConfigurationManager.AppSettings("Web2.Config")
    Dim con As SqlConnection
    Dim cmd As SqlCommand
    Dim rdr As SqlDataReader
    Dim sql As String
    Dim t As String

    Protected Sub btnlogin_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnlogin.Click
        con = New SqlConnection(str)
        con.Open()
        Dim type As String
        type = ddltype.SelectedValue
        If type = "Customer" Then
            sql = "select CusID, Password2 from Customer_Regis where uname='" + tuname.Text + "' and upass='" + tupass.Text + "'"
        ElseIf type = "Delivery Boy" Then
            sql = "select DelID, Password1 from DeliveryBoy_Regis where uname='" + tuname.Text + "' and upass='" + tupass.Text + "'"

        Else
            sql = "select ManID, Password from Manager_Regis where uname='" + tuname.Text + "' and upass='" + tupass.Text + "'"

        End If
        cmd = New SqlCommand(sql, con)
        rdr = cmd.ExecuteReader
        If rdr.Read Then
            If ddltype.SelectedValue = "Customer" Then
                Session("ses_dname") = rdr("CusFName") + " " + rdr("CusLName")
                Session("ses_uid") = rdr("CusID")
                Response.Redirect("mypage.aspx")
            ElseIf ddltype.SelectedValue = "Delivery Boy" Then
                Session("ses_dname") = rdr("DelFName") + " " + rdr("DelLName")
                Session("ses_uid") = rdr("DelID")
                Session("ses_utype") = rdr("Designation")
                Response.Redirect("index.aspx")
            Else
                Session("ses_dname") = rdr("ManFName") + " " + rdr("ManLName")
                Session("ses_uid") = rdr("ManID")
                Session("ses_utype") = rdr("Designation")
                Response.Redirect("default2.aspx")
            End If
        End If

    End Sub

    Protected Sub ddltype_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddltype.SelectedIndexChanged

    End Sub
End Class

Dim str As String = ConfigurationManager.AppSettings("Web2.Config") What is web2.config? is it a file name or name of the connection string in the web.config file?

The configuration file of an asp.net application must be web.config.

Also the connection string should be placed in <connectionStrings> section in asp.net 2.0.
For Example

<configuration>
	<connectionStrings>
		<add name="connectionStringName" connectionString="ConnectionString" providerName="System.Data.SqlClient" /> 
	</connectionStrings>
</configuration>

Also you can get connection information in your code using

Dim connectionString As String = System.Configuration.ConfigurationManager.ConnectionStrings("connectionStringName").ConnectionString

I followed what you said. This is the error i get next in line 15. 'Compiler Error Message: BC30455: Argument not specified for parameter 'Number' of 'Public Function Str(Number As Object) As String'.
please help.


Line 13:
Line 14: Protected Sub btnlogin_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnlogin.Click
Line 15: con = New SqlConnection(str)Line 16: con.Open()
Line 17: Dim type As String

con = New SqlConnection(str)

Str is a built-in function in VB.NET, therefore you should not use that.

Change the variable name str to something like strConn.

Hope this will help you.

I have done it and i am getting an error at this part 'con.Open()'. It says The ConnectionString property has not been initialized. This happens when i am running the system. please help

Protected Sub btnlogin_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnlogin.Click
        'Dim connectionString As String = System.Configuration.ConfigurationManager.ConnectionStrings("connectionStringName").ConnectionString
        Dim strConn As String
        con = New SqlConnection(strConn)
        [B]con.Open()[/B]
        Dim type As String
        type = ddltype.SelectedValue
        If type = "Customer" Then
            sql = "select CusID, Password2 from Customer_Regis where uname='" + tuname.Text + "' and upass='" + tupass.Text + "'"
        ElseIf type = "Delivery Boy" Then
            sql = "select DelID, Password1 from DeliveryBoy_Regis where uname='" + tuname.Text + "' and upass='" + tupass.Text + "'"

        Else
            sql = "select ManID, Password from Manager_Regis where uname='" + tuname.Text + "' and upass='" + tupass.Text + "'"

        End If
        cmd = New SqlCommand(sql, con)
        rdr = cmd.ExecuteReader
        If rdr.Read Then
            If ddltype.SelectedValue = "Customer" Then
                Session("ses_dname") = rdr("CusFName") + " " + rdr("CusLName")
                Session("ses_uid") = rdr("CusID")
                Response.Redirect("Home.aspx")
            ElseIf ddltype.SelectedValue = "Delivery Boy" Then
                Session("ses_dname") = rdr("DelFName") + " " + rdr("DelLName")
                Session("ses_uid") = rdr("DelID")
                Session("ses_utype") = rdr("Designation")
                Response.Redirect("index.aspx")
            Else
                Session("ses_dname") = rdr("ManFName") + " " + rdr("ManLName")
                Session("ses_uid") = rdr("ManID")
                Session("ses_utype") = rdr("Designation")
                Response.Redirect("default2.aspx")
            End If
        End If

    End Sub

chriscross86,

Very pity!!

I don't understand why are you ignoring... Wrap up source code with BB code tags.

Uncomment first statement within the click handler or assign connection string to the StrConn string variable.

Protected Sub btnlogin_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnlogin.Click

   Dim connectionString As String = 
         System.Configuration.ConfigurationManager.ConnectionStrings("connectionStringName").ConnectionString

   con = New SqlConnection(connectionString)
   con.Open()
   Dim type As String
   type = ddltype.SelectedValue
   If type = "Customer" Then
         sql = "select CusID, Password2 from Customer_Regis where 
               uname='" + tuname.Text + "' and upass='" + tupass.Text 
                    + "'"
  ElseIf type = "Delivery Boy" Then
         sql = "select DelID, Password1 from DeliveryBoy_Regis where 
              uname='" + tuname.Text + "' and upass='" + tupass.Text 
              + "'"
Else
        sql = "select ManID, Password from Manager_Regis where 
                uname='" + tuname.Text + "' and upass='" + tupass.Text 
          + "'"
End If
cmd = New SqlCommand(sql, con)
rdr = cmd.ExecuteReader
If rdr.Read Then
   If ddltype.SelectedValue = "Customer" Then
      Session("ses_dname") = rdr("CusFName") + " " + rdr
                     ("CusLName")
      Session("ses_uid") = rdr("CusID")
               Response.Redirect("Home.aspx")
  ElseIf ddltype.SelectedValue = "Delivery Boy" Then
       Session("ses_dname") = rdr("DelFName") + " " + rdr
        ("DelLName")
       Session("ses_uid") = rdr("DelID")
       Session("ses_utype") = rdr("Designation")
       Response.Redirect("index.aspx")
Else
       Session("ses_dname") = rdr("ManFName") + " " + rdr
        ("ManLName")
       Session("ses_uid") = rdr("ManID")
       Session("ses_utype") = rdr("Designation")
       Response.Redirect("default2.aspx")
   End If
End If
End Sub
<?xml version="1.0"?>
<!-- 
    Note: As an alternative to hand editing this file you can use the 
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in 
    machine.config.comments usually located in 
    \Windows\Microsoft.Net\Framework\v2.x\Config 
-->
<configuration>
  <configSections>
    <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
      <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
        <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
        <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
          <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
          <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
          <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
          <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
        </sectionGroup>
      </sectionGroup>
    </sectionGroup>
  </configSections>
  <appSettings/>
  <connectionStrings>
    <add name="CourierSystemConnectionString" connectionString="Data Source=USER-91BA9E332B\SQLEXPRESS;Initial Catalog=CourierSystem;Integrated Security=True"
 providerName="System.Data.SqlClient" />
  </connectionStrings>
  <system.web>
    <!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.

            Visual Basic options:
            Set strict="true" to disallow all data type conversions 
            where data loss can occur. 
            Set explicit="true" to force declaration of all variables.
        -->
    <compilation debug="true" strict="false" explicit="true">
      <assemblies>
        <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
      </assemblies>
    </compilation>
    <pages>
      <namespaces>
        <clear/>
        <add namespace="System"/>
        <add namespace="System.Collections"/>
        <add namespace="System.Collections.Generic"/>
        <add namespace="System.Collections.Specialized"/>
        <add namespace="System.Configuration"/>
        <add namespace="System.Text"/>
        <add namespace="System.Text.RegularExpressions"/>
        <add namespace="System.Linq"/>
        <add namespace="System.Xml.Linq"/>
        <add namespace="System.Web"/>
        <add namespace="System.Web.Caching"/>
        <add namespace="System.Web.SessionState"/>
        <add namespace="System.Web.Security"/>
        <add namespace="System.Web.Profile"/>
        <add namespace="System.Web.UI"/>
        <add namespace="System.Web.UI.WebControls"/>
        <add namespace="System.Web.UI.WebControls.WebParts"/>
        <add namespace="System.Web.UI.HtmlControls"/>
      </namespaces>
      <controls>
        <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      </controls>
    </pages>
    <!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
        -->
    <authentication mode="Windows"/>
    <!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
    <httpHandlers>
      <remove verb="*" path="*.asmx"/>
      <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
    </httpHandlers>
    <httpModules>
      <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    </httpModules>
  </system.web>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
        <providerOption name="CompilerVersion" value="v3.5"/>
        <providerOption name="WarnAsError" value="false"/>
      </compiler>
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" warningLevel="4" type="Microsoft.VisualBasic.VBCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
        <providerOption name="CompilerVersion" value="v3.5"/>
        <providerOption name="OptionInfer" value="true"/>
        <providerOption name="WarnAsError" value="false"/>
      </compiler>
    </compilers>
  </system.codedom>
  <!-- 
        The system.webServer section is required for running ASP.NET AJAX under Internet
        Information Services 7.0.  It is not necessary for previous version of IIS.
    -->
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules>
      <remove name="ScriptModule"/>
      <add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    </modules>
    <handlers>
      <remove name="WebServiceHandlerFactory-Integrated"/>
      <remove name="ScriptHandlerFactory"/>
      <remove name="ScriptHandlerFactoryAppServices"/>
      <remove name="ScriptResource"/>
      <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    </handlers>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
</configuration>

From the web.config, the name of the connection string is 'CourierSystemConnectionString'.

Therefore your code should be as below

Dim strConn As String = 
System.Configuration.ConfigurationManager.ConnectionStrings("CourierSystemConnectionString").ConnectionString

con = New SqlConnection(strConn)
con.Open()
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