Question

如何加载WPF的 Main 形式，以便当表单处于公寓状态时，单独的线程会从数据库中获取数据？（可拖动/可移动）

我知道这可以从你的主表单打开一个新窗口，如下所示：

Private Sub openOrderWindow()
    Dim OrderWindow As Orders = New Orders
    OrderWindow.ShowDialog()
End Sub

Private Sub ButtonImport_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles ButtonImport.Click
    Dim iThread As System.Threading.Thread = New System.Threading.Thread(AddressOf openOrderWindow)
    iThread.SetApartmentState(System.Threading.ApartmentState.STA)
    iThread.Start()
    ListViewOrderDetail.Focus()
    ' Me.Close()
End Sub

因为我使用'ShowDialog'

但是在主窗口我无法调用ShowDialog

我的尝试：

 Private Sub AccessDBFilling()
ListViewDataGrid.ItemsSource = Nothing
    accessdblist = Nothing
accessdblist = accessdb.GetFromAccess()
ListViewDataGrid.ItemsSource = accessdblist
End Sub

 Private Sub refresh()
    ListViewDataGrid.Dispatcher.Invoke(New Action(AddressOf AccessDBFilling))
End Sub

Private Sub Window_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
    iThread = New System.Threading.Thread(AddressOf refresh)
    iThread.SetApartmentState(System.Threading.ApartmentState.STA)
    iThread.Start()
End Sub

我尝试过MyBase.ShowDialog()和.Show()以及.9000+其他内容

我使用单独的线程从数据库加载的唯一好处是我可以立即看到屏幕（反对它是一个透明的盒子，直到它加载）但我不能移动它或最小化它

有没有办法让它在加载时可移动？

Answer 1

是。你应该明白你做了什么。

ListViewDataGrid.Dispatcher.Invoke(New Action(AddressOf AccessDBFilling))

UI控件的调度程序对应于UI线程。所以UI被冻结，因为你在UI线程上精确加载数据。

这是你应该做的：

Private Sub AccessDBFilling()
    ListViewDataGrid.ItemsSource = Nothing
    accessdblist = Nothing
    accessdblist = accessdb.GetFromAccess()
    //I'm not sure, but you can try the following lines of code. uncomment one of them.

    //ListViewDataGrid.Dispatcher.Invoke(() => ListViewDataGrid.ItemsSource = accessdblist);
    //ListViewDataGrid.ItemsSource = accessdblist;
End Sub

Private Sub Window_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
    Action loadFromDb = AccessDBFilling;
    loadFromDb.BeginInvoke();
End Sub

由于我不懂VB，你应该从C＃中翻译它：）

WPF加载，以便我可以移动表单

1 个答案: