invalid attempt to call checkdataisready when reader is closed

Question

Hi, Can someone help me how to fix this problem in vb.net. Error Message : invalid attempt to call checkdataisready when reader is closed Private Sub txtBarcode_KeyDown(sender As System. Object , e As System.Windows.Forms.KeyEventArgs) Handles txtBarcode.KeyDown Try If e.KeyCode = Keys.Enter Then con = New SqlConnection(cs) con.Open() Dim ctn1 As String = "select * from Company" cmd = New SqlCommand(ctn1) cmd.Connection = con rdr = cmd.ExecuteReader() If Not rdr.Read() Then MessageBox.Show( "Add company profile first in master entry" , "" , MessageBoxButtons.OK, MessageBoxIcon.Information) If (rdr IsNot Nothing ) Then rdr.Close() End If Return End If If con.State = ConnectionState.Open Then con.Close() End If con = New SqlConnection(cs) con.Open() cmd = con.CreateCommand() cmd.CommandText = "SELECT PID,RTRIM(PurchaseUnit),PurchaseCost,RTRIM(ProductCode),RTRIM(ProductName),SalesCost from Product where Barcode=@d1" cmd.Parameters.AddWithValue( "@d1" , txtBarcode.Text) rdr = cmd.ExecuteReader() If rdr.Read() Then lblUnit.Visible = True txtProductID.Text = rdr.GetValue(0) lblUnit.Text = rdr.GetValue(1).ToString() txtPricePerQty.Text = rdr.GetValue(2) txtProductCode.Text = rdr.GetValue(3).ToString() cmbProductName.Text = rdr.GetValue(4).ToString() txtSalesRate.Text = rdr.GetValue(5) cmbStorageType.SelectedIndex = 0 cmbWarehouse.SelectedIndex = 0 txtQty.Focus() If (rdr IsNot Nothing ) Then rdr.Close() End If End If If con.State = ConnectionState.Open Then con.Close() End If End If Catch ex As Exception MessageBox.Show(ex.Message, "Error" , MessageBoxButtons.OK, MessageBoxIcon. Error ) End Try End Sub

Praveen Kumar · Answer

Hi, I fixed the issue, Private Sub txtBarcode_KeyDown(sender As System.Object, e As System.Windows.Forms.KeyEventArgs) Handles txtBarcode.KeyDown Try If e.KeyCode = Keys.Enter Then con = New SqlConnection(cs) Dim ctn1 As String = "select * from Company" cmd = New SqlCommand(ctn1, con) con.Open() rdr = cmd.ExecuteReader() If Not rdr.Read() Then MessageBox.Show("Add company profile first in master entry", "", MessageBoxButtons.OK, MessageBoxIcon.Information) If (rdr IsNot Nothing) Then rdr.Close() End If Return End If Dim ctn2 As String = "SELECT PID,RTRIM(PurchaseUnit),PurchaseCost,RTRIM(ProductCode),RTRIM(ProductName),SalesCost from Product where Barcode=@d1" Dim cmd2 As SqlCommand Dim rdr2 As SqlDataReader cmd2 = New SqlCommand(ctn2, con) cmd2.Parameters.AddWithValue("@d1", txtBarcode.Text) rdr2 = cmd2.ExecuteReader() If rdr2.Read() Then lblUnit.Visible = True txtProductID.Text = rdr2.GetValue(0) lblUnit.Text = rdr2.GetValue(1).ToString() txtPricePerQty.Text = rdr2.GetValue(2) txtProductCode.Text = rdr2.GetValue(3).ToString() cmbProductName.Text = rdr2.GetValue(4).ToString() txtSalesRate.Text = rdr2.GetValue(5) cmbStorageType.SelectedIndex = 0 cmbWarehouse.SelectedIndex = 0 txtQty.Focus() If (rdr2 IsNot Nothing) Then rdr2.Close() End If End If If con.State = ConnectionState.Open Then con.Close() End If End If Catch ex As Exception MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error) End Try End Sub

Kelvin Mugambi · Answer

Hello brother...I have the same error when i click a button to load a product in a datagrid. Kindly help me solve it.

Praveen Kumar · Answer

Hi Jignesh, Good day. Thank for your reply and with your help i fixed the issue.

Praveen Kumar · Answer

Hi Amit, Thanks for your help and i fixed the issue.

Amit Gupta · Answer

Please take my words in a positive way and do follow the steps given from 2nd paragraph, it will solves your issue.

Jignesh Kumar · Answer

Hi, You are closing reader before using it. Please try to close reader once read done, rdr.Close() need to put proper place. refer this link, https://www.vbforums.com/showthread.php?568240-RESOLVED-Invalid-attempt-to-call-MetaData-when-reader-is-closed

Praveen Kumar · Answer

Hi Mr.Amit Gupta, Good day. Thanks for your replay. I believe there is no need to discuss about the coding standard here. I am looking for solution only and not a comment. If you are capable give me good solution. thanks,

Amit Gupta · Answer

Hey I am not a vb guy but as per error and code review, I am sorry to say your code smells very bad and doesn't follow any coding standards. Anyway, the error depicts that the reader is closed when you are reading data from it. Instead of using rdr.Close() everytime, replace it with using block like using (var rdr=new SqlDataReader) use in vb accordingly { .. do your stuff } and same applied to SqlConnection object also or its better to create a seperated DataAccess Layer class that do all your suffs neatly