如何防止 vb.net 应用程序滞后

Question

我的应用程序变成了一个大应用程序，随着时间的推移具有多种功能，基本上它过滤，并为仓库项目做一些代码，每个部分/流派都有特殊的功能。

所以当我放置文件并单击开始按钮时，它会冻结而不是使用计时器..因为有些文件有超过 3000 行

我如何让等待而不是应用程序冻结，例如 web 应用程序和 Vpns 等大型应用程序。

我的计时器代码是基本的，计算文件行数是最大数，并且在将我的代码应用于每一行后，将 1 添加到变量中：

Private Sub BtnStart_Click(sender As Object, e As EventArgs) Handles Button1.Click
   For Each line In textbox1.text
   #Alot of code
   next
   dim x as integer= ProgressBar1.value
   x += 1
   ProgressBar1.value = x

End If

结束子

Answer 1

线程几乎肯定是答案，而且它可能会变得复杂。 几分钟前，我刚刚在另一个问题上发布了一个使用线程的工作示例（ richtextbox for = i multiple function ）。 该OP希望一次运行2个线程，直到处理完richtextbox中的所有shell命令。

这段代码有效并且正是这样做的； 我希望它至少可以为您提供进一步探索的起点。 根据您的需要，您可以使用WHILE循环在每个线程完成工作时更新您的进度条。

Imports System.Threading

Public Class Form1
    Dim Thread1 As Thread
    Dim Thread2 As Thread
    Dim Thread1cmd As String = ""
    Dim Thread2cmd As String = ""
    Dim Thread1Running As Boolean = False
    Dim Thread2Running As Boolean = False
    Dim LastCmd As Int32 = -1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        LastCmd = -1
        While LastCmd < RichTextBox1.Lines.Count
            If Thread1Running = False And (LastCmd + 1) < RichTextBox1.Lines.Count Then
                LastCmd += 1
                Thread1cmd = RichTextBox1.Lines(LastCmd)
                output.Text += LastCmd.ToString + " Thread 1: " + Thread1cmd + vbCrLf
                Thread1 = New Thread(AddressOf Thread1Helper)
                Thread1.IsBackground = True
                Thread1.Start()
            End If
            If Thread2Running = False And (LastCmd + 1) < RichTextBox1.Lines.Count Then
                LastCmd += 1
                Thread2cmd = RichTextBox1.Lines(LastCmd)
                output.Text += LastCmd.ToString + " Thread 2: " + Thread2cmd + vbCrLf
                Thread2 = New Thread(AddressOf Thread2Helper)
                Thread2.IsBackground = True
                Thread2.Start()
            End If
            'Note - there is debate around the DoEvents that follows, so experiment with it and see what works best for you
            Application.DoEvents()
            'the main thread now sleeps to give helper threads time to do some work:
            System.Threading.Thread.Sleep(200)
        End While
    End Sub
    Sub Thread1Helper()
        Thread1Running = True
        Dim p1 As System.Diagnostics.Process
        Try
            p1 = New System.Diagnostics.Process
            Dim MyCMD As String = Environment.GetFolderPath(Environment.SpecialFolder.System) + "\cmd"
            p1.StartInfo.FileName = MyCMD
            p1.StartInfo.Arguments = " /c " + """" + Thread1cmd + "&&PAUSE" + """"
            'MsgBox(p1.StartInfo.FileName.ToString)
            p1.Start()
            p1.WaitForExit()
            p1.Close()
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
        Thread1Running = False
    End Sub
    Sub Thread2Helper()
        Thread2Running = True
        Dim p2 As System.Diagnostics.Process
        Try
            p2 = New System.Diagnostics.Process
            Dim MyCMD As String = Environment.GetFolderPath(Environment.SpecialFolder.System) + "\cmd"
            p2.StartInfo.FileName = MyCMD
            p2.StartInfo.Arguments = " /c " + """" + Thread2cmd + "&&PAUSE" + """"
            'MsgBox(p2.StartInfo.FileName.ToString)
            p2.Start()
            p2.WaitForExit()
            p2.Close()
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
        Thread2Running = False
    End Sub

End Class