Question

我在VB.NET的Windows窗体上有列表框，列表框包含从数据库填充的作业列表。然后使用列表框中选择的值构建SQL语句，然后发送该语句以创建报告。我的问题是，我希望列表框在选择一个特定项目时取消选择所有其他项目。基本上我的问题是，当我选择项目0（所有作业的列表）时，我希望取消选择所有其他项目，如果选择了任何其他项目，则必须取消选择项目0。项目0 =基本上是一组工作。剩余项目=个人工作。以下是我用来加载列表框的代码

Public Sub CommandCollection()
        Dim connetionString As String = Nothing
        Dim connection As SqlConnection
        Dim command As SqlCommand
        Dim adapter As New SqlDataAdapter()
        Dim ds As New DataSet()
        Dim i As Integer = 0
        ListBox1.Enabled = False
        BtnClosedJobActualQuoteViewer_Click.Enabled = True
        Dim sql As String = Nothing
        connetionString = "Data Source=DEV-TST235\SQLEXPRESS2005;Initial Catalog=TSTracker;Integrated Security=True"
        sql = "SELECT -1 JobId, '<All>' JobNumber" & _
                " UNION " & _
                " SELECT * from (SELECT DISTINCT Jobs.JobId,RTRIM(Jobs.JobNumber) JobNumber FROM Jobs INNER JOIN" & _
                " Companies (NOLOCK) ON Jobs.CustomerID = Companies.CompanyID INNER JOIN" & _
                " JobHistory (NOLOCK) ON Jobs.JobID = JobHistory.JobID" & _
                " WHERE  (JobHistory.modifiedDate > '" & StartDate.Value.ToShortDateString & "') AND (JobHistory.modifiedDate < '" & EndDate.Value.ToShortDateString & "') AND (JobHistory.Description = 'Job Closed')" & _
                ")a ORDER BY JobNumber"
        connection = New SqlConnection(connetionString)
        Try
            connection.Open()
            command = New SqlCommand(sql, connection)
            adapter.SelectCommand = command
            adapter.Fill(ds)
            adapter.Dispose()
            command.Dispose()
            connection.Close()
            ListBox1.DataSource = ds.Tables(0)
            ListBox1.ValueMember = "JobId"
            ListBox1.DisplayMember = "JobNumber"
            ListBox1.ClearSelected()
            If ListBox1.Items.Count > 1 Then
                ListBox1.Enabled = True
            Else
                ListBox1.Enabled = False
                ListBox1.DataSource = Nothing
                ListBox1.Items.Clear()
                BtnClosedJobActualQuoteViewer_Click.Enabled = False
            End If
        Catch ex As Exception
            MessageBox.Show("Can not open connection ! ")
        End Try
    End Sub

及以下是我可以设法在选择索引= 0的项目时取消选择所选项目的代码，这是答案的一半，但我也希望它以其他方式发生，我的意思是如果其他项目如选择其他然后在index = 0处的项目，则必须取消选择index = 0处的项目。

 Dim index As Integer
            index = ListBox1.SelectedIndex
            If index = 0 Then
                ListBox1.SelectedItems.Clear()
                ListBox1.SetSelected(0, True)
            ElseIf index <> 0 Then
                ListBox1.SetSelected(0, False)
            End If
        End If

Answer 1

您可以尝试这样的事情：

    ' If only 1 item is selected, then do nothing
    If ListBox1.SelectedItems.Count > 1 Then
        ' If there is more than one item selected and 
        ' one of those items is the first item
        If ListBox1.SelectedIndex = 0 Then
            ' Clear all selected items
            ListBox1.SelectedItems.Clear()
            ' Select only the first item
            ListBox1.SetSelected(0, True)
        End If
    End If

在列表框中选择特定项目时取消选择项目

1 个答案: