有没有简单的方法来设置WPF StatusBar文本？

Question

我想在我的 StatusBar 中设置 TextBlock 的文本，然后让用户在我的程序执行一些工作时等待一小会儿。

显然，我不能做一个像这样的漂亮的小函数（这不起作用）：

Function Load(ByVal Id As Guid) As Thing
    Cursor = Cursors.Wait
    TextBlockStatus.Text = "Loading..."
    TextBlockStatus.UpdateLayout()
    Dim Found = From t In db.Thing _
                Where t.Id = Id _
                Select t
    TextBlockStatus.Text = String.Empty
    Cursor = Cursors.Arrow
    Return Found
End Function

我必须使用这个怪物：

Private WithEvents LoadWorker As BackgroundWorker

Private Sub Window1_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
    InitializeLoadWorker()
End Sub

Private Sub InitializeLoadWorker()
    LoadWorker = New BackgroundWorker
    LoadWorker.WorkerSupportsCancellation = False
    LoadWorker.WorkerReportsProgress = False
    AddHandler LoadWorker.DoWork, AddressOf LoadBackgroundWorker_DoWork
    AddHandler LoadWorker.RunWorkerCompleted, AddressOf LoadBackgroundWorker_RunWorkerCompleted
End Sub

Sub Load(ByVal Id As Guid)
    Cursor = Cursors.Wait
    LoadWorker.RunWorkerAsync(Argument)
End Sub

Private Sub LoadBackgroundWorker_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs)
    Dim Worker As BackgroundWorker = DirectCast(sender, BackgroundWorker)
    Dim Id As Guid = DirectCast(e.Argument, Guid)
    e.Result = From t In db.Thing _
               Where t.Id = Id _
               Select t
End Sub

Private Sub LoadBackgroundWorker_RunWorkerCompleted(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs)
    TextBlockStatus.Text = String.Empty
    Cursor = Cursors.Arrow
    Dim Found As Thing = DirectCast(e.Result, Thing)
    'now do something with the found thing here instead of where Load() is called.'
End Sub

并且 Load() 函数现在是一个 Sub！

一定有更好的方法来处理如此简单的情况。 这不需要是异步的。

Answer 1

看一下这个问题：在 WPF 中显示等待屏幕。

接受的答案有一种方法可以做我认为你想做的事情，而无需后台工人阶级。

从另一个问题的答案中的链接来看，这可能适用于 VB.NET（不过我还没有尝试过）

Public Sub AllowUIToUpdate()

    Dim frame As New DispatcherFrame()

    Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Render, New DispatcherOperationCallback(AddressOf JunkMethod), frame)

    Dispatcher.PushFrame(frame)

End Sub

Private Function JunkMethod(ByVal arg As Object) As Object

    DirectCast(arg, DispatcherFrame).Continue = False
    Return Nothing

End Function