problem overriding connection string from web.config file

vaquas khan

16y16.9k.NET

hi all,

i want use my web.config file connectionstring to my crystal report.my code is given below.

protected void Page_Load(object sender, EventArgs e)

{

TextBox1.Text = Session["Selected"].ToString();

TextBox2.Text = Session["ReportBy"].ToString();

TextBox3.Text = Session["FromDate"].ToString();

TextBox4.Text = Session["ToDate"].ToString();

ReportDocument repDoc = new ReportDocument();

string MyconnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

SqlConnectionStringBuilder SConn = new SqlConnectionStringBuilder(MyconnectionString);

repDoc.DataSourceConnections[0].SetConnection(SConn.DataSource, SConn.InitialCatalog, SConn.UserID, SConn.Password);

repDoc.Load(Server.MapPath("Report/RptExpiryListByitem.rpt"));

ParameterDiscreteValue objDiscreteValue;

ParameterField objParameterField;

objDiscreteValue = new ParameterDiscreteValue();

objParameterField = new ParameterField();

objDiscreteValue.Value =TextBox1.Text;

objParameterField = CrystalReportViewer1.ParameterFieldInfo["@strIDs"];

objParameterField.CurrentValues.Add(objDiscreteValue);

CrystalReportViewer1.ParameterFieldInfo.Add(objParameterField);

objDiscreteValue.Value = TextBox2.Text;

objParameterField = CrystalReportViewer1.ParameterFieldInfo["@intFilterType"];

objParameterField.CurrentValues.Add(objDiscreteValue);

CrystalReportViewer1.ParameterFieldInfo.Add(objParameterField);

objDiscreteValue.Value = TextBox3.Text;

objParameterField = CrystalReportViewer1.ParameterFieldInfo["@dtFromDate"];

objParameterField.CurrentValues.Add(objDiscreteValue);

CrystalReportViewer1.ParameterFieldInfo.Add(objParameterField);

objDiscreteValue.Value = TextBox4.Text;

objParameterField = CrystalReportViewer1.ParameterFieldInfo["@dtToDate"];

objParameterField.CurrentValues.Add(objDiscreteValue);

CrystalReportViewer1.ParameterFieldInfo.Add(objParameterField);

CrystalReportViewer1.ReportSource =repDoc;

}

when i run my apllication and pass the parameter to the report its give the error ..

System.NullReferenceException: Object reference not set to an instance of an object.

at line

 string MyconnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

please anyone provide me the solution for this problem..

thanks

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Manikavelu Velayutham16y ago
Here is the issue.
You have stored the connectionstring in appsettings. Thats why the error occured.
You have to fetch from appsettings using the below code

string MyconnectionString = ConfigurationManager.AppSettings["ConnectionString"].ToString();
vaquas khan16y ago
Dear Manikavelu Velayutham,

can u provide above code in c# ,i run my application on development server not IIS,
my web.config file(connection string ) is given below
Manikavelu Velayutham16y ago
There might be two reasons for this error.
1. Check in IIS, whether the application pointing to correct web.config file. Becuase sometimes, the virtual directory will be pointing to different web.config file.

2. Try the below code to read the connection string, it will fetch it without any error.
Public Shared Sub ReadConnectionStrings()

    ' Get the ConnectionStrings collection.
    Dim connections _
        As ConnectionStringSettingsCollection = _
            ConfigurationManager.ConnectionStrings

    If connections.Count <> 0 Then
        Console.WriteLine()
        Console.WriteLine( _
            "Using ConnectionStrings property.")
        Console.WriteLine( _
            "Connection strings:")

        ' Get the collection elements.
        For Each connection _
            As ConnectionStringSettings In connections
            Dim name As String = connection.Name
            Dim provider As String = _
                connection.ProviderName
            Dim connectionString As String = _
                connection.ConnectionString

            Console.WriteLine( _
                "Name:               {0}", name)
            Console.WriteLine( _
                "Connection string: {0}", _
                    connectionString)
            Console.WriteLine( _
                "Provider:            {0}", provider)
        Next
    Else
        Console.WriteLine()
        Console.WriteLine( _
            "No connection string is defined.")
        Console.WriteLine()
    End If
End Sub

3. Check the name of connectionstring in the web.config file, sometimes if its mismatches, it will throw this error.
4. Try to add a quick watch while debugging and see what are all the values available in the configuratino manager.

let me know if you still cant fix the issue