急急急！！！麻烦各位高手，帮我解决一下这个问题
Public Class preOrderPublic id As String
Public Const style As String = "预定"
Public rdate As Date
Public num As String
End Class
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim sqlstr As String
Dim order As New preOrder
order = GetDataFromForm()
If order.id = "" Then
Exit Sub
End If
If order.num = "" Then
Exit Sub
End If
sqlstr = "INSERT INTO 预订订单信息(预订订单号,预订类型,需求日期,房号桌号列表) VALUES ('" & order.id & "'," & _
"'" & order.style & "','" & CDate(Now.ToShortDateString) & "','" & order.num & "')"
If UpdateData(sqlstr) = True Then
Me.ListBox1.Items.Add(Me.TextBox1.Text)
MsgBox("订单添加成功!", MsgBoxStyle.OKOnly + _
MsgBoxStyle.Exclamation, "登记成功")
Else
MsgBox("该订单已经存在，此次添加失败。", _
MsgBoxStyle.OKOnly + MsgBoxStyle.Exclamation, "添加失败")
Exit Sub
End If
GetAllData()
ShowData(0)
AlterStatus(True)
End Sub
Public Sub GetAllData()
Dim sqlstr As String
Dim ds As New DataSet
ds.Clear()
Me.ListBox1.Items.Clear()
sqlstr = "SELECT 预订订单号 FROM 预订订单信息 WHERE 预订类型='预定'"
ds = GetDataFromDB(sqlstr)
Dim i As Integer
Dim temp As String
If Not ds Is Nothing Then
For i = 0 To ds.Tables(0).Rows.Count - 1
temp = Trim(ds.Tables(0).Rows(i)("预订订单号").ToString)
Me.ListBox1.Items.Add(temp)
Next
End If
End Sub
Public Function GetDataFromForm() As preOrder
Dim order As New preOrder
order.id = Trim(Me.TextBox1.Text)
order.rdate = CDate(Me.DateTimePicker1.Value.ToShortDateString)
order.num = Trim(Me.TextBox2.Text)
End Function
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim sqlstr As String
sqlstr = "DELETE FROM 预订订单信息 WHERE 预订订单号=" & _
"'" & Me.TextBox1.Text.Trim & "'"
UpdateData(sqlstr)
AlterStatus(False)
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim order As New preOrder
order = GetDataFromForm()
If order.id = "" Then
Exit Sub
End If
Dim sqlstr As String
With order
sqlstr = "UPDATE 预订订单信息 SET 需求日期='" & .rdate & "'," & _
"桌号房号列表='" & .num & "' WHERE 预订订单号='" & .id & "'"
End With
UpdateData(sqlstr)
AlterStatus(True)
End Sub
Private Sub frmOrderInfo_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
GetAllData()
If Me.ListBox1.Items.Count > 0 Then
Me.ListBox1.SetSelected(0, True)
ShowData(0)
End If
End Sub
Public Function ShowData(ByVal index As Integer)
If index >= 0 Then
Dim order As New preOrder
order = getOrder(Trim(Me.ListBox1.SelectedItem.ToString))
Me.TextBox1.Text = order.id
Me.DateTimePicker1.Value = order.rdate
Me.TextBox2.Text = order.num
End If
End Function
Public Function getOrder(ByVal orderid As String) As preOrder
Dim sqlstr As String
Dim order As New preOrder
sqlstr = "SELECT * FROM 预订订单信息 WHERE 预订订单号='" & orderid & "'"
Dim ds As New DataSet
ds.Clear()
ds = GetDataFromDB(sqlstr)
If Not ds Is Nothing Then
order.id = ds.Tables(0).Rows(0)("预订订单号")
order.rdate = ds.Tables(0).Rows(0)("需求日期")
order.num = ds.Tables(0).Rows(0)("房号桌号列表")
End If
Return order
End Function
Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
Dim i As Integer
i = Me.ListBox1.SelectedIndex
If i >= 0 Then
ShowData(i)
End If
End Sub
Public Sub AlterStatus(ByVal add As Boolean)
Dim temp As String
Dim str As String
Dim num As Integer
temp = Trim(Me.TextBox2.Text)
Do While temp.Length > 0
If temp.Length = 1 Then
num = CInt(temp)
Else
str = temp.Substring(0, temp.IndexOf(","))
num = CInt(str.Trim)
temp = temp.Remove(0, str.Length + 1)
End If
Dim sqlstr As String
If add = True Then
sqlstr = "UPDATE 预订信息 SET 可用状态='被预定'" & _
" WHERE 桌号='" & num & "'"
Else
sqlstr = "UPDATE 预订信息 SET 可用状态='空闲' " & _
"WHERE 桌号='" & num & "'"
End If
UpdateData(sqlstr)
Loop
End Sub
End Class
运行的时候，会弹出错误提示“未将对象引用设置到对象的实例” 并标记 order = getOrder(Trim(Me.ListBox1.SelectedItem.ToString）） 这句话
跪求各位高手帮帮忙！！！！小弟感激不尽
--------------------编程问答-------------------- Me.ListBox1.SelectedItem.ToString 这个没取到东东吧，是不是NOTHING状态啊 --------------------编程问答-------------------- 怎么看是不是 NOTHING状态啊？ --------------------编程问答-------------------- Me.ListBox1.SelectedItem没有选择
为null --------------------编程问答-------------------- If ListBox1.SelectedItem IsNot Nothing Then
End If --------------------编程问答--------------------
我实在是个菜鸟，麻烦了 能不能具体点指出应该写在哪儿啊？焦头烂额中…… --------------------编程问答--------------------
非常感谢！！！好用了 嘿嘿 --------------------编程问答-------------------- --------------------编程问答-------------------- 谁能来点视频vb2008
补充：.NET技术 , VB.NET
