Question

我在删除listview中的最后一项时遇到问题。如果我有，让我们说列表视图中有3个联系人，删除3个联系人中的2个是没问题的。列表视图将自动刷新，3个联系人中的2个将从列表中删除。但是，如果我要删除最后一个和第三个联系人，列表视图将不会更新或刷新，除非我退出表单并重新打开它。

以下是我的代码

Private Sub ContactTab_load()
    If sConnection.State = ConnectionState.Closed Then
        sConnection.ConnectionString = Search.sqlConnect
        sConnection.Open()
    End If

    Dim sqlAdapter As New MySqlDataAdapter
    Dim sqlCommand As New MySqlCommand
    Dim sqlTable As New DataTable
    Dim sqlText As String

    nameForm.nameSearch = nameForm.nameListView.SelectedItems(0).Text
    Dim InstitutionContactName As String = nameForm.nameSearch
    InstitutionContactName = InstitutionContactName.Replace("'", "''")

    sqlText = "select c.contact_id, c.contact_first_name,c.contact_last_name,c.primary_phone,c.primary_email, ct.contact_type_name, ihc.institution_id from institution i left outer join institution_has_contact ihc on i.institution_id = ihc.institution_id left outer join contact c on ihc.contact_id = c.contact_id join contact_type ct on ct.contact_type_id = c.contact_type_id where institution_name='" & InstitutionContactName & "' order by contact_first_name"

    If Search.debugging Then
        MsgBox("sql=" & sqlText)
    End If

    With sqlCommand
        .CommandText = sqlText
        .Connection = sConnection
    End With

    With sqlAdapter
        .SelectCommand = sqlCommand
        .Fill(sqlTable)
    End With

    If sqlTable.Rows.Count > 0 Then

        InstitutionContactListView.Items.Clear()
        For i = 0 To sqlTable.Rows.Count - 1
            With InstitutionContactListView
                .Items.Add(sqlTable.Rows(i)("contact_id"))
                With .Items(.Items.Count - 1).SubItems
                    .Add(sqlTable.Rows(i)("contact_first_name"))
                    .Add(sqlTable.Rows(i)("contact_last_name"))
                    .Add(sqlTable.Rows(i)("primary_phone"))
                    .Add(sqlTable.Rows(i)("primary_email"))
                    .Add(sqlTable.Rows(i)("contact_type_name"))
                End With
            End With
        Next
        sqlTable.Dispose()
        sqlCommand.Dispose()
        sqlAdapter.Dispose()
    End If

    If InstitutionContactListView.Items.Count > 0 Then
        InstitutionContactListView.Items(0).Selected = True
    End If
End Sub

这是删除联系人的代码

Private Sub RemoveContactButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RemoveContactButton.Click
    If ContactIDSelected > -1 Then
        RunSql("delete from institution_has_contact where institution_id = " & InstitutionID & " and contact_ID=" & ContactIDSelected)
        ContactTab_load()
    Else
        MsgBox("Select a Contact to be removed")
    End If
End Sub

为什么会发生这种情况的任何想法？

Answer 1

您的ContactTab_load程序未考虑查询返回的行：

If sqlTable.Rows.Count > 0 Then

    InstitutionContactListView.Items.Clear()
    For i = 0 To sqlTable.Rows.Count - 1
        With InstitutionContactListView
    ' ...

将Clear移动到循环外部，以便在删除/删除最后一项时，LV被清除：

InstitutionContactListView.Items.Clear()
If sqlTable.Rows.Count > 0 Then

    For i = 0 To sqlTable.Rows.Count - 1
        With InstitutionContactListView
    ' ...

或者，添加一个ELSE来做同样的事情。

删除listview vb.net上的最后一项后，Listview不会刷新或更新

1 个答案: