VB.NET WinForms - 如何从BackgroundWorker的线程访问主线程的对象？

Question

我正在使用BackgroundWorker，我希望BackgroundWorker从数据库中检索数据，同时用户仍然可以在表单上执行其他任务。问题是，检索数据后，我似乎无法从 BackgroundWorker 的 DoWork 事件访问我的 Form 中的 ListView，我将使用我检索到的数据填充该 ListView。我应该怎么办？我错过了什么吗？

考虑这个例子，这就是我的做法:

Public Class Test
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        BackgroundWorker1.RunWorkerAsync()
    End Sub

    Private Sub BackgroundWorker1_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        Label1.Text = "Hello World"
    End Sub
End Class

Answer 1

BackgroundWorker 的文档非常清楚:

You must be careful not to manipulate any user-interface objects in your DoWork event handler. Instead, communicate to the user interface through the ProgressChanged and RunWorkerCompleted events.

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样本"How to: Download a File in the Background"显示了在主线程和后台工作程序之间共享对象的一种示例方式 - 通过安排将此类对象存储在类级别的变量中。