如何在Do Loop语句运行时保持表单响应 [英] How to keep a form responsive whilst a Do Loop statement is running

问题描述

如果运行以下代码，将会看到在Do[...]Loop语句运行时无法单击Button2:

If you run the following code you will see that you can not click Button2 whilst the Do[...]Loop statement is running:

Imports Microsoft.Office.Interop

Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

        Dim xlApp As New Excel.Application
        xlApp.Visible = True
        Dim wb1 As Excel.Workbook
        wb1 = xlApp.Workbooks.Open("C:\Book1.xlsx")


        Dim wsSheet1 As Excel.Worksheet
        wsSheet1 = CType(wb1.Sheets(1), Excel.Worksheet)

        Do
            wsSheet1.Cells.Copy()
            wsSheet1.Cells.PasteSpecial(Paste:=Excel.XlPasteType.xlPasteValues)
        Loop

    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        MsgBox("Hello")
    End Sub

End Class

在Do[...]Loop语句运行时如何保持Form1响应?

How do you keep Form1 responsive whilst the Do[...]Loop statement is running?

推荐答案

为了在Do[...]Loop语句运行时保持表单响应，您需要使用

In order to keep your form responsive whilst the Do[...]Loop statement is running you need to run it on a separate thread using the Task class.

首先创建一个新方法并将Do[...]Loop语句放置在该方法中:

First create a new method and place the Do[...]Loop statement in that method:

Private Sub CopyCells(ByVal worksheet As Excel.Worksheet)

    Do
        worksheet.Cells.Copy()
        worksheet.Cells.PasteSpecial(Paste:=Excel.XlPasteType.xlPasteValues)
    Loop

End Sub

然后，您可以使用任务来调用此方法.Factory.StartNew :

Task.Factory.StartNew(Sub() CopyCells(wsSheet1))

我也将不再使用MsgBox并使用MessageBox.Show. MsgBox对于VB6存在，并且最终还是委派给MessageBox，因此使用MessageBox.Show有意义:

I would also move away from using MsgBox and use MessageBox.Show. MsgBox exists for VB6 and ends up delegating to MessageBox anyway so makes sense to use MessageBox.Show:

MessageBox.Show("Hello")

完整来说，您的代码将类似于以下内容:

In full your code would look something similar to this:

Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

        Dim xlApp As New Excel.Application
        xlApp.Visible = True

        Dim wb1 As Excel.Workbook
        wb1 = xlApp.Workbooks.Open("C:\Book1.xlsx")

        Dim wsSheet1 As Excel.Worksheet
        wsSheet1 = CType(wb1.Sheets(1), Excel.Worksheet)

        Task.Factory.StartNew(Sub() CopyCells(wsSheet1))

    End Sub

    Private Sub CopyCells(ByVal worksheet As Excel.Worksheet)

        Do
            worksheet.Cells.Copy()
            worksheet.Cells.PasteSpecial(Paste:=Excel.XlPasteType.xlPasteValues)
        Loop

    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        MessageBox.Show("Hello")
    End Sub

End Class

请注意，您必须导入System.Threading.Tasks才能使用Task类.

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