Report Viewer error: An error has occurred during report processing. Cannot create a data reader for dataset payslip in ASP.Net

Hi adnanali,

Here in your code if you are assigning ReportViewer ProcessingMode also the LocalReport ReportPath but you have not used any Datasource value to assign report viewer. Because of that error is raising. If you will place an debugger in your IsPostBack code you will find the error after ReportViewer1.LocalReport.ReportPath = Server.MapPath("~/Report2.rdlc") line. If you don’t want to bind ReportViwer on page load the simply add those two line before BindReport Method call in TextChanged event.

Refer the below code for your reference. also implement it as per your code.

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
    }
}

private void BindReport(DataSet dsCustomers)
{
    ReportDataSource datasource = new ReportDataSource("Customers", dsCustomers.Tables[0]);
    ReportViewer1.LocalReport.DataSources.Clear();
    ReportViewer1.LocalReport.DataSources.Add(datasource);
}

protected void TextChanged(object sender, EventArgs e)
{
    string country = txtCountry.Text.Trim();
    ReportViewer1.ProcessingMode = ProcessingMode.Local;
    ReportViewer1.LocalReport.ReportPath = Server.MapPath("~/Report.rdlc");
    BindReport(GetFilteredDataSet("Customers_GetCustomersCountryWise", country));
}

private DataSet GetFilteredDataSet(string procedure, string country)
{
    using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString))
    {
        SqlCommand cmd = new SqlCommand();
        if (!string.IsNullOrEmpty(country))
        {
            cmd.Parameters.Add(new SqlParameter("@CountryName", txtCountry.Text.Trim()));
        }
        cmd.Connection = con;
        cmd.CommandText = procedure;
        cmd.CommandType = CommandType.StoredProcedure;
        DataSet ds = new DataSet();
        using (SqlDataAdapter da = new SqlDataAdapter(cmd))
        {
            da.Fill(ds);
        }
        return ds;
    }
}

private Customers GetData(string query)
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    SqlCommand cmd = new SqlCommand(query);
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter())
        {
            cmd.Connection = con;
            sda.SelectCommand = cmd;
            using (Customers dsCustomers = new Customers())
            {
                sda.Fill(dsCustomers, "DataTable1");
                return dsCustomers;
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
    End If
End Sub

Private Sub BindReport(dsCustomers As DataSet)
    Dim datasource As New ReportDataSource("Customers", dsCustomers.Tables(0))
    ReportViewer1.LocalReport.DataSources.Clear()
    ReportViewer1.LocalReport.DataSources.Add(datasource)
End Sub

Protected Sub TextChanged(sender As Object, e As EventArgs)
    Dim country As String = txtCountry.Text.Trim()
    ReportViewer1.ProcessingMode = ProcessingMode.Local
    ReportViewer1.LocalReport.ReportPath = Server.MapPath("~/Report.rdlc")
    BindReport(GetFilteredDataSet("Customers_GetCustomersCountryWise", country))
End Sub

Private Function GetFilteredDataSet(procedure As String, country As String) As DataSet
    Using con As New SqlConnection(ConfigurationManager.ConnectionStrings("constr").ConnectionString)
        Dim cmd As New SqlCommand()
        If Not String.IsNullOrEmpty(country) Then
            cmd.Parameters.Add(New SqlParameter("@CountryName", txtCountry.Text.Trim()))
        End If
        cmd.Connection = con
        cmd.CommandText = procedure
        cmd.CommandType = CommandType.StoredProcedure
        Dim ds As New DataSet()
        Using da As New SqlDataAdapter(cmd)
            da.Fill(ds)
        End Using
        Return ds
    End Using
End Function

Private Function GetData(query As String) As Customers
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Dim cmd As New SqlCommand(query)
    Using con As New SqlConnection(conString)
        Using sda As New SqlDataAdapter()
            cmd.Connection = con
            sda.SelectCommand = cmd
            Using dsCustomers As New Customers()
                sda.Fill(dsCustomers, "DataTable1")
                Return dsCustomers
            End Using
        End Using
    End Using
End Function