This is my code , i am new to VB.net, exception os unhandled that object reference is not set to the instance of an object. in data base all are int which i m passing from VB.Net and ID is auto increment, what should i do,
Public Class Maintainance
Dim cn As New System.Data.SqlClient.SqlConnection
Sub connect()
cn = New System.Data.SqlClient.SqlConnection("Data Source=localhost;Initial Catalog=Fleet Maintainance;Integrated Security=True")
End Sub
Sub lockall()
cBx1.Enabled = False
cBx2.Enabled = False
tBx1.Enabled = False
tBx2.Enabled = False
tBx3.Enabled = False
End Sub
Sub unlockall()
cBx1.Enabled = True
cBx2.Enabled = True
tBx1.Enabled = True
tBx2.Enabled = True
tBx3.Enabled = True
End Sub
Sub setall()
cBx1.Text = ""
cBx2.Text = ""
tBx1.Text = ""
tBx2.Text = ""
tBx3.Text = ""
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If cBx1.Enabled = True Then
Dim str As String
str = "insert into AddMaintainanceTask (MainID, TypeID, PartCost, LaborCost, Total) values (" & (cBx1.SelectedValue.ToString()) & ", " & (cBx2.SelectedValue.ToString()) & ", " & CInt(tBx1.Text) & "," & CInt(tBx2.Text) & "," & CInt(tBx3.Text) & ")"
Call connect()
Dim cd As New System.Data.SqlClient.SqlCommand(str, cn)
cd.Connection.Open()
cd.ExecuteNonQuery()
cd.Connection.Close()
MsgBox(" New Task is added successfully ")
Call lockall()
Me.Close()
Call IssueWorkOrder.listView2load()
Else
MsgBox(" Task is not added Try again ")
End If
End Sub
Sub updatecombo1()
Call connect()
Dim cd As New System.Data.SqlClient.SqlCommand("SELECT [Name],[NameID] FROM [RepairName] order by [Name]", cn)
Dim adp As New System.Data.SqlClient.SqlDataAdapter(cd)
Dim ds As New DataSet
adp.Fill(ds)
cBx1.DisplayMember = "Name"
cBx1.ValueMember = "NameID"
cBx1.DataSource = ds.Tables(0)
End Sub
Sub updatecombo2()
Call connect()
Dim cd As New System.Data.SqlClient.SqlCommand("SELECT [RepairType],[RepairTypeID] FROM [RepairType] order by [RepairType]", cn)
Dim adp As New System.Data.SqlClient.SqlDataAdapter(cd)
Dim ds As New DataSet
adp.Fill(ds)
cBx2.DisplayMember = "RepairType"
cBx2.ValueMember = "RepairTypeID"
cBx2.DataSource = ds.Tables(0)
End Sub
Sub updatecombo3()
Call connect()
Dim cd As New System.Data.SqlClient.SqlCommand("SELECT [Service],[ServiceID] FROM [Service] order by [Service]", cn)
Dim adp As New System.Data.SqlClient.SqlDataAdapter(cd)
Dim ds As New DataSet
adp.Fill(ds)
cBx1.DisplayMember = "Service"
cBx1.ValueMember = "ServiceID"
cBx1.DataSource = ds.Tables(0)
End Sub
Private Sub RadioButton1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RadioButton1.CheckedChanged
RadioButton1.Text = "Preventive"
End Sub
Private Sub RadioButton2_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RadioButton2.CheckedChanged
RadioButton2.Text = "Repair"
End Sub
Private Sub RadioButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RadioButton1.Click
Call updatecombo3()
Label3.Text = "Service"
cBx2.Enabled = False
End Sub
Private Sub RadioButton2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RadioButton2.Click
Call updatecombo1()
Call updatecombo2()
Label3.Text = "Repair"
cBx2.Enabled = True
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
AddService.Show()
AddService.Visible = True
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.Close()
End Sub
Private Sub Maintainance_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
Private Sub tBx3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tBx3.TextChanged
End Sub
End Class