編程方式更改組合框選擇，而不會導致的SelectedIndexChanged火災

Question

所以我有對的SelectedIndexChanged事件處理程序的組合框：

Private Sub cmbStatus_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbStatus.SelectedIndexChanged 
     DoAnnoyingStuff() 
     '.... 
    End sub 

別處在我的形式，我有做這樣的功能（後一些用戶交互） ：

Sub RefreshStatus() 
    Dim sel As Int32 = GetNewStatus() 
    cmbStatus.SelectedIndex = sel '<-- fires a SelectedIndexChanged event that I don't need 
End Sub 

我想在RefreshStatus做的（）有什麼改變在組合框中顯示的選擇，但不執行DoAnnoyingStuff（）。我該怎麼做呢？

Answer 1

您可以手動管理事件，啓用和使用禁用的處理程序：

AddHandler cmbStatus.SelectedIndexChanged, AddressOf cmbStatus_SelIndexChg 
RemoveHandler cmbStatus.SelectedIndexChanged, AddressOf cmbStatus_SelIndexChg  

正如所說，你可以使用一個標誌：

Dim bRefreshStatus As Boolean = False 

Private Sub cmbStatus_SelIndexChg(sender As Object, e As EventArgs) Handles cmbStatus.SelectedIndexChanged 
    If Not bRefreshStatus Then DoAnnoyingStuff() 
End Sub 

Sub RefreshStatus() 
    Dim sel As Int32 = GetNewStatus() 
    bRefreshStatus = True 
    cmbStatus.SelectedIndex = sel 
    bRefreshStatus = False 
End Sub 

Answer 2

添加旗子。所以你會有一個名爲_inChange的私人類字段作爲布爾值，然後在RefreshStatus開始時將該字段設置爲true，最後將該字段設置爲false。在cmbStatus_SelectedIndexChanged中檢查_inChange是否爲真。如果是你只是退出。如果錯誤，則繼續並執行AnnoyingStuff。