vb.net 高精度定时器

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在vb.net下常用的计时器非组件中的Timer莫属，但是实际应用的时候大家会发现一个比较大的问题，精度不够。
我写了个代码来测试timer的精度，间隔时间设置为1毫秒，具体代码如下：

    Dim counter1 As Integer
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If Timer1.Enabled = True Then
            Timer1.Stop()
        Else
            Timer1.Start()
        End If
    End Sub


    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        counter1 += Timer1.Interval
        TextBox1.Text = counter1
    End Sub


    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        counter1 = 0
        Timer1.Interval = 1
    End Sub

结果对比手机时间，实测得到计时次数为 38360，确实相差比较大。
因此我考虑了如下代码：

Public Class CustomTimer
    Public Property Interval As Integer
    Public Event Tick()
    Public Property Enabled As Boolean
    Sub New()
        Me.Interval = 100
        Me.Enabled = False
    End Sub

    Sub New(ByVal Interval As Integer)
        Me.Interval = Interval
        Me.Enabled = False
    End Sub

    Public Sub Start()
        Me.Enabled = True
        Dim th As New Threading.Thread(AddressOf count)
        th.Priority = Threading.ThreadPriority.Highest
        th.Start()
    End Sub

    Private Sub count()
        Do While Me.Enabled = True
            Threading.Thread.Sleep(Interval)
            RaiseEvent Tick()
        Loop
    End Sub

    Public Sub [Stop]()
        Me.Enabled = False
    End Sub
End Class

窗体调用代码：
 

    Dim counter1 As Integer
    Dim counter2 As Integer

    Dim ct As CustomTimer

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.CheckForIllegalCrossThreadCalls = False
        counter1 = 0
        counter2 = 0
        Timer1.Interval = 1

        ct = New CustomTimer(1)
        AddHandler ct.Tick, AddressOf CustomTimer_Tick
    End Sub

    Private Sub CustomTimer_Tick()
        counter2 += ct.Interval
        TextBox2.Text = counter2
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        If ct.Enabled = True Then
            ct.Stop()
        Else
            ct.Start()
        End If
    End Sub

经过测试，手机秒表时间 1'00.23 ，程序计数次数：57676

也就是60230对应57676，比系统Timer精度要高。

由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。

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