WPF - 卸载后销毁页面 运行

WPF - destroy page after unloaded has run

在 WPF 应用程序中,我们有时需要创建一个包含框架内页面的新选项卡..

打开页面(初始化一次)后,它似乎仍保留在导航历史记录中并尝试加载当时可能不相关的数据。

我尝试了无数种方法,包括NavigationService.RemoveBackEntry,但它仍然存在:-(

这是 tab/page 如何打开的示例

 Private Sub CashFlow_Edit(sender As Object, e As RoutedEventArgs)
    Try
        Dim DGV As DGVx = ReportsCashFlow_Grid.FindName("CashFlow_DGV")
        e.Handled = True
        IsNewRecord = False

        If DGV.SelectedItems.Count = 1 Then
            Dim row As System.Data.DataRowView = DGV.SelectedItems(0)
            Form_ID = row("ID")
            Dim vName As String = row("Name")
            Dim vTab As STC_Tabx = Application.Current.MainWindow.FindName(TabName)
            Dim TabControl As STCx = Application.Current.MainWindow.FindName("AccountingReports_TabControl")
            If Not vTab Is Nothing Then
                vTab.Close()
            End If
            Dim MCFrame As New Frame
            Dim MCTab As New STC_Tabx
            With MCTab
                .Name = TabName
                .Header = " " & vName & " "
                .ImageSource = ReturnImageAsString("Edit.png", 16)
                .CloseButtonVisibility = DevComponents.WpfEditors.eTabCloseButtonVisibility.Visible
                .TabToolTip = "View or edit the " & vName & " template"
                .Content = MCFrame
            End With
            RemoveHandler MCTab.Closing, AddressOf TabControl_TabClosing
            AddHandler MCTab.Closing, AddressOf TabControl_TabClosing

            Dim vGrid As Grid = Application.Current.MainWindow.FindName("MainGrid_Accounting")
            RegisterControl(vGrid, MCTab)
            TabControl.Items.Add(MCTab)
            Dim MCPage As New ReportCashFlow_Page
            MCFrame.NavigationService.Navigate(MCPage)
            LoadedTabs(TabName)
            MCTab.IsSelected = True


        End If

    Catch ex As Exception
        EmailError(ex)
    End Try
End Sub

要删除所有后面的条目,请执行以下操作:

while(NavigationService.CanGoBack)
{
    NavigationService.RemoveBackEntry();
}

这不是我想要的干净代码,但它可以工作 - 创建一个全局布尔值 - 当调用打开 tab/page 的子程序时,它被设置为 true 并且加载事件只会 运行 加载代码,如果这是 true - 最后设置为 false。

Private Sub ReportCashFlow_Page_Loaded(sender As Object, e As RoutedEventArgs) Handles Me.Loaded
    Try


        If IsNewTab = False Then
            Exit Sub
        End If
 'Run all the loading code here


  Catch ex As Exception
        EmailError(ex)
    Finally
        IsNewTab = False
        Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, CType(Sub() CashFlow_LoadBudget(), SendOrPostCallback), Nothing)
        Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, CType(Sub() ToggleReserve(), SendOrPostCallback), Nothing)
    End Try
End Sub