初始化struc时的奇怪行为 [英] a strange behavior in initializing a struc

问题描述

在Visual C ++ 2012中，我在初始化struc时遇到了一个奇怪的行为。基本上，我有这个文件

can.h

 #ifndef _CANDEMO_H_ 
 #define _CANDEMO_H_ 
 
 //定义
 #define MAX_CHANNELS 63 //不能更多因为waitforsingle对象可以"仅"处理64个事件
 
 //包括
 #include< canlib.h> 
 
 
 //用于调试/错误目的
 #if 1 
 #define PRINTF_ERR（x）printf x 
 #else 
 #define PRINTF_ERR（x）
 #endif 
 
 
 // typedefs 
 typedef struct {
 int channel; 
 char name [100]; 
 DWORD hwType; 
 canHandle hnd; 
 int hwIndex; 
 int hwChannel; 
 int isOnBus; 
 int driverMode; 
 int txAck; 
} ChannelDataStruct; 
 
 
 typedef struct {
 unsigned int channelCount; 
 ChannelDataStruct频道[MAX_CHANNELS]; 
} driverData; 
 
 #endif 

和CAN.cpp文件

 #include" stdio.h中" 
 #include" CAN.h" 
 
 //模块全局变量
 unsigned int m_usedBaudRate = 0; 
 canHandle m_usedChannel; 
 unsigned int m_usedId; 
 unsigned int m_usedFlags = 0; 
 unsigned int m_Verbose = 1; 
 
 driverData m_channelData; 
 driverData * m_DriverConfig =& m_channelData; 
 
 
 int main（int argc，char ** argv）
 {
 
} 
 

当我在主{}之前运行Can.cpp时，结果为

 m_channelData.channelCount = 0 

 
 
 
 
如果我在windows窗体应用程序创建的项目中运行此代码，如下所示
 
 #include" stdafx.h" 
 #include" Form1.h" 
 #include" CAN.h" 
 
 
 unsigned int m_usedBaudRate = 0; 
 canHandle m_usedChannel; 
 unsigned int m_usedId; 
 unsigned int m_usedFlags = 0; 
 unsigned int m_Verbose = 1; 
 
 driverData m_channelData; 
 driverData * m_DriverConfig =& m_channelData; 
 
 
使用命名空间CANproject; 
 [STAThreadAttribute] 
 int main（array< System :: String ^> ^ args）
 {
 control canGUI; 
 canGUI.InitDriver（）; 
 
 //在创建任何控件之前启用Windows XP视觉效果
 Application :: EnableVisualStyles（）; 
 Application :: SetCompatibleTextRenderingDefault（false）; 
 
 //创建主窗口并运行它
 Application :: Run（gcnew Form1（））; 
 
返回0; 
} 
 
 
然后，在int main {}之前，m_channelData.channelCount被初始化为一个非常高的值，看起来像一个随机数。 
 
我不明白为什么???感谢您的帮助
 
 

解决方案

我正在将此线程移至 Visual C ++ 论坛以获得更好的响应。

祝你好运，

In Visual C++ 2012, I got a strange behavior in initializing a struc. Basically, I have this file

can.h

#ifndef _CANDEMO_H_
#define _CANDEMO_H_

//defines
#define MAX_CHANNELS 63   //cannot be more because waitforsingle object can "only" handle 64 events

//includes
#include <canlib.h>


//for debug/error purposes
#if 1
#define PRINTF_ERR(x)     printf x
#else
#define PRINTF_ERR(x)
#endif  


//typedefs
typedef struct {
  int        channel;
  char       name[100];
  DWORD      hwType;
  canHandle  hnd;
  int        hwIndex;
  int        hwChannel;
  int        isOnBus;
  int        driverMode;
  int        txAck;
} ChannelDataStruct;


typedef struct {
  unsigned int       channelCount;
  ChannelDataStruct  channel[MAX_CHANNELS];
} driverData;

#endif

and the CAN.cpp file

#include "stdio.h"
#include "CAN.h"

// module globals
unsigned int   m_usedBaudRate                  = 0;
canHandle      m_usedChannel;
unsigned int   m_usedId;
unsigned int   m_usedFlags                     = 0;
unsigned int   m_Verbose                       = 1;

driverData     m_channelData;
driverData    *m_DriverConfig                 = &m_channelData;


int main(int argc, char **argv)
{
  
}

When I ran Can.cpp, before the main {}, the result is

m_channelData.channelCount=0

if I run this code inside a project created by windows form application, as shown below
#include "stdafx.h"
#include "Form1.h"
#include "CAN.h"
unsigned int   m_usedBaudRate                  = 0;
canHandle      m_usedChannel;
unsigned int   m_usedId;
unsigned int   m_usedFlags                     = 0;
unsigned int   m_Verbose                       = 1;

driverData     m_channelData;
driverData    *m_DriverConfig                 = &m_channelData;
using namespace CANproject;	
[STAThreadAttribute]
int main(array<System::String ^> ^args)
{   
	control canGUI;
	canGUI.InitDriver();

	// Enabling Windows XP visual effects before any controls are created
	Application::EnableVisualStyles();
	Application::SetCompatibleTextRenderingDefault(false); 
	
	// Create the main window and run it
	Application::Run(gcnew Form1());

	return 0;
}
then, right before the int main {},  m_channelData.channelCount is initialized with a very high valued, looking like a random number. 
I dont understand why ??? Thanks for helping

解决方案

Hi,

I am moving this thread to Visual C++ forum for better response.

Best regards,

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