打开串口文件API函数CreateFile，高手请进，急！！！

[wyuanzhi920]

Dim lHandle As Long
lHandle = CreateFile("COM1", GENERIC_READ Or GENERIC_WRITE, 0&, 0&, OPEN_EXISTING, 0&, 0&)请问这样调用有什么问题吗，为什么每次lHandle都返回-1
急，先谢谢了！！！

[DooDu]

你api是如何声明的？

Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, ByVal lpSecurityAttributes As Long, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long

是byval

[wyuanzhi920]

Public Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, lpSecurityAttributes As SECURITY_ATTRIBUTES, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long

是啊，一样的声明啊

[wyuanzhi920]

如可以可以加我的QQ：25169482，谢谢了！

[wyuanzhi920]

在线等.......

[DooDu]

lpSecurityAttributes As SECURITY_ATTRIBUTES???

[wyuanzhi920]

Public Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, lpSecurityAttributes As Long, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long
是这个

[wyuanzhi920]

编译可以通过的，只是返回值为-1

[DooDu]

请仔细看看我给你的声明和你用的声明的区别在哪里。

[wyuanzhi920]

你的：
Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, ByVal lpSecurityAttributes As Long, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long
我的：
Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, ByVal lpSecurityAttributes As Long, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long

还是一样的啊！

[wyuanzhi920]

能在QQ里聊吗

[wyuanzhi920]

我用你的声明也还是一样返回-1啊，不知道为什么？

[DooDu]

ComNum = CreateFile("COM1", &HC0000000, 0, 0&, &H3, 0, 0)

[wyuanzhi920]

这个可以了，谢谢！！！现在我把分给你！

[KissApple]

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