传递unicode字符串 [英] Passing unicode string

问题描述

大家好，

如何将unicode sring参数传递给函数?是否需要任何转换?
因此，我必须传递Unicode字符串，例如Run(L"Query")..
然后在我的实现代码中，我就这样定义了

Hye all,

How do I pass unicode sring parameter to my function? Was there any conversion needed?
So I have to pass the unicode string for example Run(L"Query")..
Then in my implementation code i define like this

void Run(wchar_t *message)
{
  DWORD cbRequest, cbWritten;
  cbRequest=sizeof(message);

  WriteFile(
        hPipe,                      // Handle of the pipe
        message,                  // Message to be written
        cbRequest,                  // Number of bytes to write
        &cbWritten,                 // Number of bytes written
        NULL                        // Not overlapped
      ));
}

但是当我进行调试时，写入的消息只是一个，即"Q" ..

but when i do debugging, the message writen was only one namely ''Q''..
How do i correct this?

推荐答案

在这种情况下，必须使用wcslen()函数而不是sizeof来获取字符串长度.

You must use wcslen() function to get string length in this case instead of sizeof.

cbRequest = wcslen(message);

Unicode字符在C ++中由wchar_t字符类型表示. Unicode字符串文字以前缀L表示，因为L是Unicode的第一个字母，或者是wide，er.
因此，当您要声明一个C样式的零终止的unicode字符字符串时，请使用:

Unicode characters are represented in C++ by the wchar_t character type. Unicode string literals are denoted by prefixing them with an L, because L is the first letter of Unicode, or wide, er, okay.

So when you want to declare a C style zero terminated string of unicode characters you use:

wchar_t *wide_text = L"I am wide text, feel my girth!";

当您要声明一个采用这种类型的字符串的函数时，可以对它进行原型制作，例如:

and when you want to declare a function that takes this type of string you''d prototype it something like:

void display_message( const wchar_t *text_to_display );

但是，这是C ++，为什么不使用std :: wstring满足所有Unicode文本需求?

干杯，

灰

PS:正如Volodya所说...

这里的问题是sizeof-您告诉它使用指针的大小，而不是要传递给函数的字符数组的大小.您可以使用wcslen之类的东西，但如果使用std :: wstring代替，则代码会更简单.

However this being C++ why not use std::wstring for all your Unicode text needs?

Cheers,

Ash

PS: As Volodya said...

Your problem here is the sizeof - you telling it to use the size of a pointer and not the size of the character array you''re passing into the function. You can use something like wcslen but had you used std::wstring instead the code would have been simpler.

更具体地说明问题.

基本上，您可以在Windows下使用LPCWSTR type或通过STL使用std::wstring.

Be more specific about the problem.

Basically you can use LPCWSTR type under Windows or std::wstring using STL.

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