清爽不工作

Question

我做出從其他引用的項目的UI組件幾個電話通過接口

UI組分：

Public Class PleaseWaitWindow 
    Implements PleaseWaitInterface 

    Sub New(initStateText As String) 

     ' This call is required by the designer. 
     InitializeComponent() 

     ' Add any initialization after the InitializeComponent() call. 
     tbStateDescription.Text = initStateText 
     Me.Activate() 
    End Sub 

    Public Property currentStepText As String Implements PleaseWaitInterface.currentStepText 

     Get 
      Return tbStateDescription.Text 
     End Get 
     Set(value As String) 
      tbStateDescription.Text = value 
      tbStateDescription.InvalidateVisual() 
     End Set 
    End Property 

    Public Sub Display() Implements PleaseWaitInterface.Display 
     Me.Show() 
     Me.Activate() 
    End Sub 

    Public Sub Dispose() Implements PleaseWaitInterface.Dispose 
     Me.Close() 
    End Sub 

    Public Property maxSteps As Integer Implements PleaseWaitInterface.maxSteps 
     Get 
      Return pbCurrentProgress.Maximum 
     End Get 
     Set(value As Integer) 
      pbCurrentProgress.Maximum = value 
     End Set 
    End Property 

    Public Sub PerformStep() Implements PleaseWaitInterface.PerformStep 
     pbCurrentProgress.Value += 1 
     pbCurrentProgress.InvalidateVisual() 
    End Sub 
End Class 

只要我做這些調用從同一項目的一切內工作

喜歡這裏：

Private Function startGeneration_normal() As Boolean 
      //Do some stuff 
        pw.PerformStep() 
        pw.currentStepText = ("Loading data, no stepping is available.") 
      tar.startworking(pw) 
      //Do some stuff 
    End Function 

但是當我通過在terfaceobject到引用的項目，並嘗試使用這樣的：

Public Function startworking(pw As PleaseWaitInterface) As Boolean 
    tempExportFileName = "Export" & DateTime.Now.ToString("yyyy-MM-dd_HH.mm") 
    //Do some stuff 
    pw.currentStepText = ("Current Task: formating XML") 
    //Do some more stuff 
End Function 

對象中的變化（在調試器檢查）的值，但視覺效果不刷新，直到從startworking功能start_generate函數返回。當它從引用項目中的函數返回時，將根據當前狀態刷新值。

爲什麼在程序執行引用項目中的內容時UI不刷新？

Answer 1

克萊門斯的解決方案，使用後臺工作的伎倆，所以
問題：
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