如何报告更改 vb.net 的进度？答案

【问题标题】：How To Report Progress Changed vb.net?如何报告更改 vb.net 的进度？
【发布时间】：2009-03-31 08:49:32
【问题描述】：

我需要报告更改的进度。考虑以下代码：

Public Class Calculator
  Public Event CalculationProgress (ByVal sender As Object, ByVal e As MyCalculationProgressEventArgs)
Public Function Calculate(..)..
' Perform calculation here ...
' Reporting proggress
Dim args As New MyCalculationProgressEventArgs(myobj, myValue)
  RaiseEvent CalculationProgress (Me, args)
...
End Class

***另一个类

Private WithEvents calculator As Calculator

Private Function PerformCalculation(ByVal obj As Object) As CalcParams
Dim params As CalcParams = CType(obj, CalcParams)
calculator = GetCalculator()
....
Return params.result = calculator.Calculate
End Function

Private Sub calculationWorker_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs) _
Handles calculationWorker.DoWork
  Dim calcResult As MyType = PerformCalculation(CType(e.Argument, MyType ))
  e.Result = calcResult
End Sub

Private Sub calculationWorker_ProgressChanged(ByVal sender As Object, ByVal e As ProgressChangedEventArgs) _
Handles calculationWorker.ProgressChanged
     CType(Parent.Parent, MainWindow).pbcCurrentProgress.Value = e.ProgressPercentage
End Sub

我应该如何以及在哪里订阅 CalculationProgress 事件来调用

 calculationWorker.ReportProgress(MyCalculationProgressEventArgs.Percent)

【问题讨论】：

标签： vb.net reporting progress

【解决方案1】：

你在这里使用BackgroundWorker 对象吗？如果是这样，您要做的是订阅calculationWorker_DoWork 事件处理程序中的CalculationProgress 事件。您没有在 MyType 上发布任何信息，因此我假设您需要更改我的代码以获取 Calculator 实例。

Private Sub calculationWorker_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs) _
  Handles calculationWorker.DoWork  

  Dim calcResult As MyType = PerformCalculation(CType(e.Argument, MyType ))  
  Dim calc = calcResult.Calculator
  AddHandler calc.CalculationProgress, AddressOf HandleCalculationProgress
  ...
  RemoveHandler calc.CalculationProgress, AddressOf HandleCalculationProgress
  e.Result = calcResult
End Sub

【讨论】：

【解决方案2】：

您可以在调用 GetCalculator 之后、调用 Calculate 之前执行此操作。

【讨论】：