C ++中使用unicode字符集的串行端口友好名称中的字节类型问题 [英] Problem with byte type in serial port friendly name in C++ using unicode character set

问题描述

我在Visual Studio中使用setupapi中的SetupDiGetDeviceRegistryProperty。如果我使用多字符集，则字节指针（BYTE * friendlyName）会提供正确的FRIENDLYNAME。但是，当我使用Unicode字符集编译它时，返回的friendlyName在字节数组中的每个值后面都有一个NULL字符。



这是代码片段：



SetupDiGetDeviceRegistryProperty（hDeviceInfo，& devInfoData，SPDRP_FRIENDLYNAME，nullptr，nullptr，0，& reqSize）;

BYTE * friendlyName = new BYTE [ 300]; //（reqSize> 1）？ reqSize：1];



if（！SetupDiGetDeviceRegistryProperty（hDeviceInfo，& devInfoData，SPDRP_FRIENDLYNAME，nullptr，friendlyName，sizeof（friendlyName）* reqSize，nullptr）） />
{

//设备没有设置此属性

memset（friendlyName，0，reqSize> 1？reqSize：1）;

}



我尝试过：



我尝试将BYTE数组（unsigned char）更改为具有相同结果的字节。如果我尝试将其更改为char，则编译器无法正常工作。



我还将数组设置为设置大小，而不是允许函数定义reqSize因为第一个字符后的NULL。

I am using SetupDiGetDeviceRegistryProperty from setupapi in Visual Studio. If I use the Multicharacter set, the byte pointer (BYTE* friendlyName) gives the correct FRIENDLYNAME. However, when I compile it using the Unicode Character set, the returned friendlyName has a NULL character behind every value in the byte array.

Here's the code snippet:

SetupDiGetDeviceRegistryProperty(hDeviceInfo, &devInfoData, SPDRP_FRIENDLYNAME, nullptr, nullptr, 0, &reqSize);
BYTE* friendlyName = new BYTE[300]; //(reqSize > 1) ? reqSize : 1];

if (!SetupDiGetDeviceRegistryProperty(hDeviceInfo, &devInfoData, SPDRP_FRIENDLYNAME, nullptr, friendlyName, sizeof(friendlyName) * reqSize, nullptr))
{
// device does not have this property set
memset(friendlyName, 0, reqSize > 1 ? reqSize : 1);
}

What I have tried:

I have tried changing the BYTE array (unsigned char) to byte with the same results. If I try to change it to char, the compiler isn't working.

I also set the array to a set size instead of allowing the function to define the reqSize because of the NULL after the first character.

推荐答案

这种行为是设计的，因为这是Unicode字符的本质。低于256的低批次跟随它们，因为它们（通常）是16位值，因此MSB将为零。



我会使用如果要在两种模式下编译，则为TCHAR宏。下面是一个示例：

This behavior is by design because that is the nature of Unicode characters. The lower batch, below value 256, have a zero following them because they are (generally) a 16-bit value so the MSB will be zero.

I would use the TCHAR macros if you are going to compile in both modes. Here's an example:

const int BufferSize = 299;
TCHAR friendlyName[BufferSize+1] = { 0 };

if( ! SetupDiGetDeviceRegistryProperty( hDeviceInfo, &devInfoData,
          SPDRP_FRIENDLYNAME, nullptr,
          friendlyName, BufferSize, nullptr ) )
{
    TRACE( _T( "device does not have this property set\n" ) );
}

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