How to create a runtime timer.tick event?

2020-04-17 06:29发布

问题:

i'm really bothered on how to create a timer.tick event on VB.net.

How my program should work:

Actually, i'm creating an FCFS algorithm and im aiming to display the gantt chart using progressbars. Regarding that, i want my timers to control a given progressbar. and after a progressbar reached its maximum, the timer will stop and the next timer will start and the next progressbar will function too. I really dont know how to do this. Im a newbie. please help me. :(

This is my code:

Private progress As New List(Of ProgressBar)

Private timex As New List(Of Timer)

For cnt4 = 0 To (Val(TextBox1.Text) - 1)

        progress.Add(New ProgressBar)
        With progress(cnt4)
            .Parent = Me
            .Left = 0
            .Height = 23
            .Width = 50
            .Top = .Height * cnt4 + 50
            .Visible = True
            .Tag = cnt4
            .Text = ""
            .Maximum = Val(burstbox(cnt4).Text)
            .Minimum = 0
            .Name = "progress" & cnt4
            .Location = New Point(17 + (.Width * cnt4), 532)

        End With

        timex.Add(New Timer)

        With timex(cnt4)

            .Tag = cnt4
            .Interval = 100
        End With

    Next


End Sub

回答1:

You would use the AddHandler Method.

timex.Add(New Timer)
AddHandler timex(cnt4).Tick, AddressOf myTickEvent

You would then create your event.

Private Sub myTickEvent(sender As Object, e As EventArgs)
    Dim instance As Integer = CInt(DirectCast(sender, Timer).Tag)

    'Do your magic here
End Sub

To flesh it out more with an working example:

Public Class Form1
    Private progress As New List(Of ProgressBar)
    Private timex As New List(Of Timer)

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

        For cnt4 = 0 To (Val(TextBox1.Text) - 1)

            progress.Add(New ProgressBar)
            With progress(cnt4)
                .Parent = Me
                .Left = 0
                .Height = 23
                .Width = 50
                .Top = .Height * cnt4 + 50
                .Visible = True
                .Tag = cnt4
                .Text = ""
                .Maximum = Val(burstbox(cnt4).Text) 'Set Maximum
                .Minimum = 0
                .Name = "progress" & cnt4
                .Location = New Point(17 + (.Width * cnt4), 532)
                Me.Controls.Add(progress(cnt4)) 'Have to add it to your Containers Control Collection
            End With

            timex.Add(New Timer)
            AddHandler timex(cnt4).Tick, AddressOf myTickEvent

            With timex(cnt4)  
                .Tag = cnt4
                .Interval = 100
            End With
        Next
        timex(0).Start()
    End Sub

    Private Sub myTickEvent(sender As Object, e As EventArgs)
        Dim instance As Integer = CInt(DirectCast(sender, Timer).Tag) 'Get Index of the Active Timer
        If progress(instance).Value >= progress(instance).Maximum Then
            timex(instance).Stop()
            RemoveHandler timex(instance).Tick, AddressOf myTickEvent
            If instance < progress.Count - 1 Then
                timex(instance + 1).Start()
            End If
        Else
            progress(instance).Value += 1
        End If
    End Sub

End Class


标签: vb.net timer