Protected Sub bpn_Click(sender As Object, e As EventArgs)
Try
Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("SQLServer2005DBConnectionString").ToString())
connection.Open()
Dim sql As String = ("select * from LOT_ WHERE PRODUCTNAME ='" & txtbpn.Text & "'")
Dim cmd As SqlCommand = New SqlCommand(sql, connection)
Using reader As SqlDataReader = cmd.ExecuteReader
If reader.HasRows Then
lblerror.Visible = False
connection.Dispose()
connection.Close()
Me.BindBpn()
txtbpn.Text = String.Empty
TextBox2.Text = String.Empty
TextBox3.Text = String.Empty
TextBox4.Text = String.Empty
TextBox5.Text = String.Empty
Else
connection.Dispose()
connection.Close()
lblerror.Text = "bpn not found"
lblerror.Visible = True
txtbpn.Text = String.Empty
TextBox2.Text = String.Empty
TextBox3.Text = String.Empty
TextBox4.Text = String.Empty
TextBox5.Text = String.Empty
End If
End Using
Catch ex As Exception
Response.Write(ex.Message)
Response.AppendHeader("Refresh", "1;url=Summary.aspx")
End Try
End Sub
1.绑定子
Private Sub BindBpn()
Using con As New SqlConnection(ConfigurationManager.ConnectionStrings("SQLServer2005DBConnectionString").ToString())
Using cmd As New SqlCommand("SELECT * FROM LOT_ WHERE PRODUCTNAME='" & txtbpn.Text & "'order by checkin asc")
Using sda As New SqlDataAdapter()
con.Open()
cmd.Connection = con
sda.SelectCommand = cmd
Dim dt As New DataTable()
sda.Fill(dt)
Dim dv As New DataView(dt)
GridView1.DataSource = dv
GridView1.DataBind()
' Me.BindGridView()
con.Close()
End Using
End Using
End Using
If GridView1.Visible = False Then
GridView1.Visible = True
End If
If Button1.Visible = False Then
Button1.Visible = True
End If
End Sub
2.当我尝试对数据进行排序时发生错误。
Protected Sub SortRecords(sender As Object, e As GridViewSortEventArgs)
Dim SortDir As String = String.Empty
Dim sortExpression As String = e.SortExpression
Dim dv As New DataView(GridView1.DataSource)
If dv IsNot Nothing Then
If direction = SortDirection.Ascending Then
direction = SortDirection.Descending
SortDir = "Desc"
ViewState("SortExpression") = Convert.ToString(e.SortExpression & " " & SortDir)
Else
direction = SortDirection.Ascending
SortDir = "Asc"
ViewState("SortExpression") = Convert.ToString(e.SortExpression & " " & SortDir)
End If
End If
dv.Sort = ViewState("SortExpression").ToString
GridView1.DataSource = dv
GridView1.DataBind()
end sub
此代码发生错误
dv.Sort = ViewState("SortExpression").ToString
任何帮助都会很棒。提前致谢
这是我的aspx GridView：
<asp:GridView ID="GridView1" width="100%" runat="server"
AllowSorting="True"
OnSorting="SortRecords"
OnRowDataBound="GridView1_RowDataBound"
ItemStyle-HorizontalAlign="Center"
AutoGenerateColumns="False" >
<Columns>
<asp:TemplateField HeaderText="ID" ItemStyle-HorizontalAlign="Center">
<ItemTemplate>
<%# Container.DataItemIndex + 1 %>
</ItemTemplate>
<ItemStyle HorizontalAlign="center" Width="5%" />
</asp:TemplateField>
<asp:BoundField DataField="Location" HeaderText="Location" />
<asp:BoundField DataField="LOT_ID" HeaderText="Lot ID" />
<asp:BoundField DataField="PkgName" HeaderText="PIN PACKAGE NAME" />
<asp:BoundField DataField="MBTBoardNo" HeaderText="MBTBoardNo" SortExpression="MBTBoardNo" />
<asp:BoundField DataField="BTProgramName" HeaderText="BT Program Name" />
<asp:BoundField DataField="ProductRank" HeaderText="ProdRank"/>
<asp:BoundField DataField="BASEPRODUCTNAME" HeaderText="BPN" />
<asp:BoundField DataField="MCNo" HeaderText="MC No" />
<asp:BoundField DataField="QTY" HeaderText="Qty" />
<asp:BoundField DataField="CreateDate" HeaderText="Start Date" />
<asp:BoundField DataField="CheckIn" HeaderText="CheckIn" />
<asp:BoundField DataField="CheckOut" HeaderText="CheckOut" />
</Columns>
</asp:GridView>
答案 0 :(得分：0)
这可能有点矫枉过正，但我需要解释一些事情。
除了Sql注入攻击之外，你还有很多其他事情要先了解。
您在排序时遇到问题，因为您没有将检索到的数据缓存到任何持久性机制。排序机制中的此代码将始终评估为Nothing：
Dim dv As New DataView(GridView1.DataSource)
除非您支持，否则GridView DataSource不会在回发中保留
使用像SqlDataSource这样的缓存数据控件来管理
缓存给你。
或者您通过以下方式之一以编程方式执行此操作：
但回归基础：
以下是帖子第一部分的经过编辑和注释的版本 我将在此之后提供清理版本：
Protected Sub bpn_Click(sender As Object, e As EventArgs)
' Added for clarity
Dim cs as String = ConfigurationManager.ConnectionStrings("SQLServer2005DBConnectionString").ToString()
' Try is generally not needed if you are using Using
' at least not here. Move it to the inner most Using block and
' wrap it around the actual command execution to catch sql errors
' you want to personally manage.
' Try
Using connection As New SqlConnection(cs)
connection.Open()
' String.Format() - learn to love this function
Dim sql As String = String.Format("select * from LOT WHERE PRODUCTNAME ='{0}' order by checkin asc", txtbpn.Text)
Dim cmd As SqlCommand = New SqlCommand(sql, connection)
' This reader is not necessary as all you are doing
' is using it to determine if there is anything to do
' This is a waste of time
' You already have one open connection and
' now you are jumping to a bind operation
' that opens more.
' Generally speaking:
' open a data connection, get the data, close the connection
Using reader As SqlDataReader = cmd.ExecuteReader
' Do this here, not in both parts of the `If`
lblerror.Visible = reader.HasRows
' lblerror.Text can be initialized here or in the .aspx
' as you do nothing else with it but toggle its visibility
' Plus you can make use of a GridView's EmptyDataText property
' and get rid of the Label altogether.
lblerror.Text = "bpn not found"
If reader.HasRows Then
Me.BindBpn()
End If
' This code is not needed as it's handled by the outer Using
' connection.Dispose()
' connection.Close()
// Since this code happens in both parts of the
// IF, it only needs to happen once.
txtbpn.Text = String.Empty
TextBox2.Text = String.Empty
TextBox3.Text = String.Empty
TextBox4.Text = String.Empty
TextBox5.Text = String.Empty
// Check your original code: 2 Using requires 2 End Using
End Using
End Using
' See Try above
Catch ex As Exception
Response.Write(ex.Message)
'Why are you trying to refresh every second?
Response.AppendHeader("Refresh", "1;url=Summary.aspx")
End Try
End Sub
以下是没有所有评论的修订代码
Protected Sub bpn_Click(sender As Object, e As EventArgs)
Dim cs as String = ConfigurationManager.ConnectionStrings("SQLServer2005DBConnectionString").ToString()
Using connection As New SqlConnection(cs)
connection.Open()
Dim sql As String = String.Format("select * from LOT WHERE PRODUCTNAME ='{0}' order by checkin asc", txtbpn.Text)
Dim cmd As SqlCommand = New SqlCommand(sql, connection)
Using sda As New SqlDataAdapter( cmd )
Try
Dim dt As New DataTable()
sda.Fill(dt)
Dim dv as New DataView(dt)
' This will persist the retrieved record set
' -- Replaced C# syntax with VB
Cache("AStringToIdentifyThisGridviewCache") = dv
GridView1.DataSource = Cache("AStringToIdentifyThisGridviewCache")
Gridview1.EmptyDataText = "bpn not found"
GridView1.DataBind()
GridView1.Visible = (GridView1.Rows.Count > 0)
txtbpn.Text = String.Empty
TextBox2.Text = String.Empty
TextBox3.Text = String.Empty
TextBox4.Text = String.Empty
TextBox5.Text = String.Empty
Catch ex As Exception
Gridview1.EmptyDataText = ex.Message
End Try
End Using
End Using
End Sub
还有一件事，你的数据将从数据库中检索出来，每次点击按钮时都会覆盖Cache并重新绑定到GridView。
通常，您希望一次检索数据，然后使用Cached数据集，直到以某种方式修改数据，这需要另一个数据库命中。
程序化数据检索和绑定当然很有用，但我发现我很少需要使用它。您可能不满足此项目的要求，但对于GridView操作，很难超越提供的DataSource控件。
希望这会有所帮助。 快乐的编码。
Protected Sub SortRecords(ByVal sender As Object, ByVal e As GridViewSortEventArgs)
'Retrieve the table from the session object.
Dim dv As DataView = TryCast(Cache("AStringToIdentifyThisGridviewCache"), DataView)
If dv IsNot Nothing Then
'Sort the data.
dv.Sort = e.SortExpression & " " & GetSortDirection(e.SortExpression)
GridView1.DataSource = Cache("AStringToIdentifyThisGridviewCache")
GridView1.DataBind()
End If
End Sub
Private Function GetSortDirection(ByVal column As String) As String
' By default, set the sort direction to ascending.
Dim sortDirection = "ASC"
' Retrieve the last column that was sorted.
Dim sortExpression = TryCast(ViewState("SortExpression"), String)
If sortExpression IsNot Nothing Then
' Check if the same column is being sorted.
' Otherwise, the default value can be returned.
If sortExpression = column Then
Dim lastDirection = TryCast(ViewState("SortDirection"), String)
If lastDirection IsNot Nothing _
AndAlso lastDirection = "ASC" Then
sortDirection = "DESC"
End If
End If
End If
' Save new values in ViewState.
ViewState("SortDirection") = sortDirection
ViewState("SortExpression") = column
Return sortDirection
End Function