Question

WCF service on IIS.
I have got a problem with reading connection string from web.config file.
my connection string looks like this :

    <connectionStrings>
  <add 
    name="ABC" 
    connectionString="DEF"
    providerName="GGG"
  />
</connectionStrings>

My code in Global.asax.cs :

protected void Application_Start(object sender, EventArgs e)
        {                    

           cons_Webdata =  WebConfigurationManager.ConnectionStrings["ABC"].ConnectionString;

        }

I have error message in “cons_Webdata = …….” :

Object reference not set to an instance of an object.

What’s wrong?
Thanks.

Answer 1

Try using ConfigurationManager instead of WebConfigurationManager

protected void Application_Start(object sender, EventArgs e)
{                    
    cons_Webdata =  ConfigurationManager.ConnectionStrings["ABC"].ConnectionString;
}

Otherwise, use the code sample from http://msdn.microsoft.com/en-us/library/ms178411.aspx

        System.Configuration.Configuration rootWebConfig =
            System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("/MyWebSiteRoot");
        System.Configuration.ConnectionStringSettings connString;
        if (rootWebConfig.ConnectionStrings.ConnectionStrings.Count > 0)
        {
            connString =
                rootWebConfig.ConnectionStrings.ConnectionStrings["NorthwindConnectionString"];
            if (connString != null)
                Console.WriteLine("Northwind connection string = \"{0}\"",
                    connString.ConnectionString);
            else
                Console.WriteLine("No Northwind connection string");
        }