在VC中折腾注册表

   碰到的问题：用遍历注册表函数RegEnumValue所得出的字符串老是被截断。这是刚开始所用的代码：

DWORD retCode;
HKEY regHKey;
CHAR achKey[MAX_PATH];
DWORD ccValue=MAX_PATH;

if(::RegOpenKeyEx(HKEY_CURRENT_USER,"Software\\OKI\\CCons33\\UNITTYPE",0,KEY_READ,&regHKey)==ERROR_SUCCESS)
{
  for(i=0,retCode=ERROR_SUCCESS;retCode!=ERROR_NO_MORE_ITEMS;i++)
 {
    retCode = ::RegEnumValue(regHKey, i,achKey,&ccValue, NULL,NULL,NULL, NULL);
    
    for(int j=0;j<strlen(achKey);j++)
    cout<<achKey[j];    

    cout<<endl;                  
  }
}

   例如“MediaPathUnexpanded”的项名，它只返回其中前面部分，就好像“MediaPathUn”，后面的就不见了，我百思不知其所,

  
  解决方法：
      正如http://topic.csdn.net/t/20040701/00/3136042.html这篇文章所说：
      通过RegQueryInfoKey可以获得value   name的最大长度的（参数lpcMaxValueNameLen），RegEnumValue中lpValueName开辟的空间比lpcMaxValueNameLen大就行了

     以下是解决的代码：
   

 1LPCSTR lp="Software\\OKI\\CCons33\\UNITTYPE";
 2                HKEY regHKey;
 3                if(::RegOpenKeyEx(HKEY_CURRENT_USER,"Software\\OKI\\CCons33\\UNITTYPE",0,KEY_READ,&regHKey)==ERROR_SUCCESS)
 4                {
 5                /**//*    ::RegQueryValueEx(regHKey,"GateKeeper#1",NULL,&nType,lpData,&size);
 6                CString str;
 7                str.Format("%s",(LPCSTR)lpData);
 8                for(int i=0;i<str.GetLength();i++)
 9                cout<<str[i];
10                    */
11                    
12                    //int i;
13                    DWORD dwIndex = 0;
14                    TCHAR *tcKeyName = NULL;
15                    DWORD dwKeyType;
16                    DWORD dwKeyDataLength,dwKeyNameLen;
17                    LPBYTE pbbinKeyData = NULL; 
18                    LONG lResult;
19                    //LPDWORD max_Path;
20                    DWORD ccValue=MAX_PATH;
21                    DWORD lNoOfValues   =   0;   
22                    DWORD lLongestKeyNameLen   =   1;   
23                    DWORD lLongestDataLen   =   1;   
24                    lResult = RegQueryInfoKey(regHKey,NULL,NULL,NULL,NULL,NULL,NULL,&lNoOfValues,
25                                    &lLongestKeyNameLen,&lLongestDataLen,NULL,NULL);   
26                    
27                    lLongestKeyNameLen++;
28                    lLongestDataLen++;
29                    tcKeyName = new TCHAR[lLongestKeyNameLen];
30                    pbbinKeyData = new BYTE[lLongestDataLen];  
31                    tcKeyName = new TCHAR[lLongestKeyNameLen];   
32                    pbbinKeyData =new BYTE[lLongestDataLen];   
33                    CString cstrFinalData,cstrTemp;   
34                    while(TRUE)   
35                    {
36                        memset(pbbinKeyData,0,lLongestDataLen);
37                        memset(tcKeyName,0,lLongestKeyNameLen);
38                        dwKeyType = dwKeyDataLength = dwKeyNameLen=0;
39                        dwKeyNameLen = lLongestKeyNameLen;
40                        dwKeyDataLength=lLongestDataLen;
41                        lResult=RegEnumValue(regHKey,dwIndex,tcKeyName,&dwKeyNameLen,NULL,&dwKeyType,pbbinKeyData,&dwKeyDataLength);
42                        if(lResult   ==   ERROR_NO_MORE_ITEMS)   
43                            break;   
44                        cout<<tcKeyName<<endl;
45                        //dRegistryItem(tcKeyName,dwKeyType,pbbinKeyData,dwKeyDataLength,dwIndex);//?帵悢悩槹ListView   
46                        dwIndex++;
47                    }
48                    RegCloseKey(regHKey);
49                    delete tcKeyName;   
50                    delete pbbinKeyData;