【 tulaoshi.com - ASP.NET 】
事实上使用Visual Basic的ActiveX exe技术可以轻松的实现多线程处理.
原理先不说了,先举个示例,有兴趣的话大家可以一起讨论
1.新建一个工程,类型选择ActiveX Exe,工程重命名为TestExe在工程中添加一个Form,放上一个Timer控件.将Class1改名为clsTest,注意其Instancing要设置为5-MultiUse, 以下是其代码:
Option ExplicitPrivate Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)Private WithEvents oTimer As TimerPrivate frmTmp As Form1Private lTotalLoop As LongPrivate bDoStop As BooleanPrivate lInterval As Long
Public Event Progress(ByVal lProgress As Long)
Public Sub StartSub(ByVal lTotal As Long) lTotalLoop = lTotal oTimer.Enabled = TrueEnd Sub
Public Sub StopSub() bDoStop = TrueEnd Sub
Private Sub Class_Initialize() Set frmTmp = New Form1 Load frmTmp Set oTimer = frmTmp.Timer1 oTimer.Enabled = False bDoStop = False lInterval = 1End Sub
Private Sub DoLoop() Dim i As Long For i = 0 To lTotalLoop Sleep (lInterval) RaiseEvent Progress(i) If bDoStop = True Then Exit Sub End If NextEnd Sub
Private Sub Class_Terminate() Unload frmTmp Set frmTmp = Nothing Set oTimer = NothingEnd Sub
Private Sub oTimer_Timer() oTimer.Enabled = False DoLoopEnd Sub
Public Property Get lMillisecs() As Long lMillisecs = lIntervalEnd Property
Public Property Let lMillisecs(ByVal vNewValue As Long) lInterval = vNewValueEnd Property
在TestExe Property(工程属性)的Threading Model中,设置Thread per Object,或者选择Thread pool中设置大于1的数值.如把Thread pool设置为2, 则调用此ActiveX Exe最多能同时有两个线程, 更多的请求将放置于队列中.编译TestExe
下面来测试我们的多线程程序:
新建一个Standard Exe工程,在Reference中选择刚刚做好的TestExe.exe在Form1中添加两个ListBox,两个CommandButton,Command1为开始,Command2为停止以下是Project1.Form1的代码:
Option ExplicitPrivate WithEvents oTest1 As TestEXE.clsTestPrivate WithEvents oTest2 As TestEXE.clsTest
Private Sub Command1_Click() Set oTest1 = New TestEXE.clsTest oTest1.lMillisecs = 100 oTest1.StartSub (1000) Set oTest2 = New TestEXE.clsTest oTest2.lMillisecs = 100 oTest2.StartSub (1000)End Sub
Private Sub Command2_Click() oTest1.StopSub oTest2.StopSubEnd Sub
Private Sub Form_Unload(Cancel As Integer) Set oTest1 = Nothing Set oTest2 = NothingEnd Sub
Private Sub oTest1_Progress(ByVal lProgress As Long) List1.AddItem lProgress List1.ListIndex = List1.ListCount - 1End Sub
Private Sub oTest2_Progress(ByVal lProgress As Long) List2.AddItem lProgress List2.ListIndex = List2.ListCount - 1End Sub
启动Project1,点击Command1,怎么样,看见来效果了吗? 试着把TestExe的Thread pool改成1看看会怎么样? 这是我认为最简单且稳固的多线程实现方法了,大家有什么好的想法欢迎留言.
