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NullReferenceException
Hello,
I am getting an error message when i show a new form and try to execute the following onload code. The program errors out @ the declarations. Thanks for any help.
Here is the code.
Imports System.Data.SqlServerCe
Imports System.IO
Public Class Totals
Inherits System.Windows.Forms.Form
#Region " Windows Form Designer generated code "
'removed
#End Region
Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
Dim cn As SqlCeConnection
Dim sqlEngine As SqlCeEngine
Dim cmd As SqlCeCommand = cn.CreateCommand
Dim da As New SqlCeDataAdapter
Closeme.Enabled = False
cn = New SqlCeConnection("Data Source=\My Documents\HandheldDBWeight .sdf")
cn.Open()
Dim NumberOfRecords As Integer
cmd.CommandText = "SELECT Count(""Wing Band Number"") FROM TemporaryWeight WHERE ""Weight"" Is Null"
cmd.Connection = cn
dr = cmd.ExecuteReader
dr.Read()
NumberOfRecords = dr.GetValue(0)
Incomplete.Text = NumberOfRecords
cmd.CommandText = "SELECT Count(""Wing Band Number"") FROM TemporaryWeight WHERE ""Weight"" Is Not Null"
cmd.Connection = cn
dr = cmd.ExecuteReader
dr.Read()
NumberOfRecords = dr.GetValue(0)
complete.Text = NumberOfRecords
Dim table As New DataTable
Dim SQL As String
SQL = "SELECT ""Cage Number"", ""Wing Band Number"", Feed, Weight FROM TemporaryWeight ORDER BY ""Cage Number"""
cmd.CommandText = SQL
cmd.Connection = cn
da.SelectCommand = cmd
da.Fill(table)
MyGrid.DataSource = table
If cn.State <> ConnectionState.Closed Then
cn.Close()
End If
MyGrid.ColumnHeadersVisibl e = False
Closeme.Enabled = True
End Sub
Private Sub Quit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Closeme.Click
Me.Close()
End Sub
End Class
Error Message...
An unhandled exception of type 'System.NullReferenceExcep tion' occurred in (Project Name).exe
I am getting an error message when i show a new form and try to execute the following onload code. The program errors out @ the declarations. Thanks for any help.
Here is the code.
Imports System.Data.SqlServerCe
Imports System.IO
Public Class Totals
Inherits System.Windows.Forms.Form
#Region " Windows Form Designer generated code "
'removed
#End Region
Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
Dim cn As SqlCeConnection
Dim sqlEngine As SqlCeEngine
Dim cmd As SqlCeCommand = cn.CreateCommand
Dim da As New SqlCeDataAdapter
Closeme.Enabled = False
cn = New SqlCeConnection("Data Source=\My Documents\HandheldDBWeight
cn.Open()
Dim NumberOfRecords As Integer
cmd.CommandText = "SELECT Count(""Wing Band Number"") FROM TemporaryWeight WHERE ""Weight"" Is Null"
cmd.Connection = cn
dr = cmd.ExecuteReader
dr.Read()
NumberOfRecords = dr.GetValue(0)
Incomplete.Text = NumberOfRecords
cmd.CommandText = "SELECT Count(""Wing Band Number"") FROM TemporaryWeight WHERE ""Weight"" Is Not Null"
cmd.Connection = cn
dr = cmd.ExecuteReader
dr.Read()
NumberOfRecords = dr.GetValue(0)
complete.Text = NumberOfRecords
Dim table As New DataTable
Dim SQL As String
SQL = "SELECT ""Cage Number"", ""Wing Band Number"", Feed, Weight FROM TemporaryWeight ORDER BY ""Cage Number"""
cmd.CommandText = SQL
cmd.Connection = cn
da.SelectCommand = cmd
da.Fill(table)
MyGrid.DataSource = table
If cn.State <> ConnectionState.Closed Then
cn.Close()
End If
MyGrid.ColumnHeadersVisibl
Closeme.Enabled = True
End Sub
Private Sub Quit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Closeme.Click
Me.Close()
End Sub
End Class
Error Message...
An unhandled exception of type 'System.NullReferenceExcep
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ASKER
thank you sir
Dim cn As SqlCeConnection
Dim sqlEngine As SqlCeEngine
Dim cmd As SqlCeCommand '= cn.CreateCommand
Dim da As New SqlCeDataAdapter
Closeme.Enabled = False
cn = New SqlCeConnection("Data Source=\My Documents\HandheldDBWeight
cn.Open()
cmd = cn.CreateCommand
Dim NumberOfRecords As Integer