CreateThread调用参数‘lpParameter’不能传递

[yixingpo]

顶层声明：

Declare Function CreateThread Lib "kernel32" _
    (lpThreadAttributes As Any, ByVal dwStackSize As Long, _
     ByVal lpStartAddress As Long, ByVal lpParameter As Long, _
     ByVal dwCreationFlags As Long, lpThreadId As Long) As Long
Dim Out3 As Long

简单调用：

Sub Test1()
    Dim lp As Long, llp As Long, x As Long
    lp = 1000
    x = CreateThread(Null, ByVal 0&, AddressOf z_pHandle.OutText3, Varptr(lp), ByVal 0&, ThreadID1)
    r = WaitForSingleObject(x, -1)
    Debug.Print Out3 & "!"
End Sub
Sub OutText3(b As Long)
    Out3 = C * 2
End Sub

lp的数值1000传递不到b中，为什么？

[赵4老师]

将lp定义为全局变量再试试

[一笑拔剑]

Sub OutText3(b As Long)
    Out3 = C * 2
    Debug.Print Out3 & "!"
End Sub

[一笑拔剑]

第一楼上这sb的话千万不能信. 第二 Sub OutText3(b As Long) Out3 = C * 2 End Sub b和out3有关系? Sub OutText3(b As Long) Out3 = b * 2 End Sub

[一笑拔剑]

另外,再vb下用CreateThread的线程很不稳定,因为vb大部分控件都不是线程安全的 而且多线程调试非常麻烦. 一崩溃就马上完蛋 我再稍微看了下你的代码 你再 Sub Test1()主线程里调用 Debug.Print Out3 & "!" 十有八九是得不到正确的输出的 Debug.Print Out3 & "!"你放到Out3 = b* 2里试下 应该就可以了

[yixingpo]

引用 3 楼 aspower_ 的回复:

另外,再vb下用CreateThread的线程很不稳定,因为vb大部分控件都不是线程安全的 而且多线程调试非常麻烦. 一崩溃就马上完蛋 我再稍微看了下你的代码 你再 Sub Test1()主线程里调用 Debug.Print Out3 & "!" 十有八九是得不到正确的输出的 Debug.Print Out3 & "!"你放到Out3 = b* 2里试下 应该就可以了

是这样的，我说一下我的想法： 在msdn中解释CreateThread的lpParameter可以传递参数。 那么我在Sub Test1程序中，利用CreateThread调用Sub OutText3(b As Long)，并传递参数lp到参数b中， 然后WaitForSingleObject等待OutText3运行完毕后，Out3应该为2*b的值，也就是2*1000. 但实际中，lp参数根本就传递不到Sub OutText3(b As Long)的b里面去，b还是0

[yixingpo]

引用 6楼赵4老师 的回复:

为什么不使用多进程呢？

呵呵…

[赵4老师]

为什么不使用多进程呢？

[PctGL]

Declare Function CreateThread Lib "kernel32" _
    (lpThreadAttributes As Any, ByVal dwStackSize As Long, _
     ByVal lpStartAddress As Long, ByVal lpParameter As Long, _
     ByVal dwCreationFlags As Long, byval lpThreadId As Long) As Long

Sub OutText3(byval b As Long) Out3 = C * 2 Debug.Print Out3 & "!" End Sub

[PctGL]

Declare Function CreateThread Lib "kernel32" _ (lpThreadAttributes As Any, ByVal dwStackSize As Long, _ ByVal lpStartAddress As Long, ByVal lpParameter As Long, _ ByVal dwCreationFlags As Long, <strong><span style="color: #FF0000;">byval</span></strong> lpThreadId As Long) As Long

[yixingpo]

引用 9 楼 PctGL 的回复:

Declare Function CreateThread Lib "kernel32" _
    (lpThreadAttributes As Any, ByVal dwStackSize As Long, _
     ByVal lpStartAddress As Long, ByVal lpParameter As Long, _
     ByVal dwCreationFlags As Long, byval lpThreadId As Long) As Long

Sub OutText3(byval b As Long) Out3 = C * 2 Debug.Print Out3 & "!" End Sub

如下：lp的数还是传不到OutText3的b中，公共变量Out3还是=0 Sub OutText3(byval b As Long) Out3 = b * 2 'Debug.Print Out3 & "!" End Sub

[PctGL]

我之前看错了，正确的结果应该是2楼代码 Sub OutText3(byval b As Long) Out3 = b * 2 Debug.Print Out3 & "!" End Sub 再把这个的c改成b，如果还有错，那就见鬼了

[赵4老师]

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