什么是Ruby Win32API参数|如何传递空指针?

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问题描述

我知道以下内容:

'L'-长
'P'-指针
'I'-整数
'V'-虚空

'L' - Long
'P' - Pointer
'I' - Integer
'V' - Void

我的问题是执行API调用时无法传递空指针.例如:['L', 'P', 'L'] -> api.call(0, nil, 0) :: ArgumentError: Null pointer given.我的问题是:还有更多我不知道的参数类型，我应该怎么做才能将空指针作为方法参数传递?

My problem is that I can't pass a null pointer when I perform an API call. E.g.: ['L', 'P', 'L'] -> api.call(0, nil, 0) :: ArgumentError: Null pointer given. My question is: Are there more parameter types that I don't know about and what should I do to pass a null pointer as a method parameter?

我一直在Internet上搜索基于WinForms的应用程序的本机Ruby编程示例.为了简化编码，我考虑了将NET添加到称为IronRuby的Ruby中(试图避免使用wxRuby，也是一个.NET迷)，但是我首先希望能够首先使用纯Ruby进行显式编码.

I have been searching the internet for native Ruby programming examples of WinForms-based applications. I have considered the .NET addition to Ruby known as IronRuby for simplicity in coding (trying to avoid wxRuby, and also a .NET fan), but I first want to be able to code explicitly in pure Ruby first.

现在，我已经能够成功实现我在user32.dll对象中测试过的大多数地址，例如:

Now, I have successfully been able to implement most addresses I've tested in the user32.dll object such as:

api = Win32API.new('user32', 'MessageBox', ['L', 'P', 'P', 'L'], 'I')
# or
api = Win32API.new('user32', 'MessageBeep', ['L'], 'I')

..但是没有空参数我无法执行CreateWindow或CreateWindowEx.如果有什么帮助，我已经在Python 此处(在WinAPI下).

..but I cannot perform a CreateWindow Or CreateWindowEx without null parameters.If it would be of any help, I have found how to do this in Python here (under WinAPI).

使用Win32API:msdn.microsoft.com/zh-cn/library/ff381397(v = VS.85).aspx

Using Win32API: msdn.microsoft.com/en-us/library/ff381397(v=VS.85).aspx

好吧，我想我可能已经通过此链接解决了自己的问题(警告:可能包含不适当的内容): [链接]

Well, I think I may have just solved my own problem with this link(warning: may contain inappropriate content): [link]

我更多地使用该论坛作为参考，并且对自己进行了一些摆弄:
createwindow = Win32API.new("user32","CreateWindowEx",'lpplllllllll','l')
showwindow = Win32API.new('user32','ShowWindow',%w(l l),'l')

I more used that forum as reference and did a bit of fiddling around my self:
createwindow = Win32API.new("user32","CreateWindowEx",'lpplllllllll','l')
showwindow = Win32API.new('user32','ShowWindow',%w(l l),'l')

hWND = createwindow.call((0x00000100|0x00000200),"static", "Window Title",((0x4000000|0x80000000|0)|0x02000000),0,0,600,400,0,0,0,0)
showwindow(hWND, 1)

在显示窗口"之后发生的唯一事情是崩溃...，这可能是由于某些不正确的处理所致，但是，我很高兴我能够使它工作(有点)！只需要弄清楚其余的...

The only thing that happens after the 'window' is displayed is crash... and that may have been because of some incorrect handling, but, I am happy that I got it to work(for a little bit)! Just need to figure out the rest...

推荐答案

与其使用Win32API(我相信它是基于晦涩且很少使用的DL模块构建的)，不如使用Win32API新的和改进的FFI模块.

Instead of using Win32API (which I believe is built on top of the obscure and little used DL module), you might find better mileage using the new and improved FFI module.

方法如下:

(1)获取ffi:
gem install ffi

(1) Get ffi:
gem install ffi

(2)然后尝试以下方法:

(2) Then try this:

require 'ffi'

module Win32
   extend FFI::Library
   ffi_lib 'user32'
   attach_function :messageBox,
       :MessageBoxA,[ :pointer, :string, :string, :long ], :int
end

rc = Win32.messageBox(nil, "Hello Ruby user!", "FFI is easy", 0x40)

puts rc

这似乎比您在编辑中发布的解决方案容易.

This seems easier than the solution you posted in your edit.

注意:用空指针代替Hwnd会使消息框没有所有者窗口.

Note: The null pointer instead of Hwnd makes the message box have no owner window.

以下一些链接可能会有所帮助:

Here are some links that may help:

要自定义的常量您的消息框(对话框框的按钮和图标)
另一个使用FFI代替Win32API

Constants to customise your message boxes (dialog box buttons and icon)
Another example using FFI instead of Win32API

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