注册表操作（一）：读取子键

整理下注册表读取子键的操作，方便以后查阅。随便找个注册表位置，如下图：

我们要读取HKEY_LOCAL_MACHINE\System\Setup下的子键，上图红框中的。

#include <windows.h>
#include <stdio.h>

#define MAX_KEY_LENGTH 255  
#define MAX_VALUE_NAME 16383 

void QueryKey(HKEY hKey)   
{   
    TCHAR    achKey[MAX_KEY_LENGTH];   //装载子键内容
    DWORD    cbName; 
    TCHAR    achClass[MAX_PATH] = TEXT("");  //装载类名
    DWORD    cchClassName = MAX_PATH; 
    DWORD    cSubKeys=0;               //子键数量
    DWORD    cbMaxSubKey;
    DWORD    cchMaxClass; 
    DWORD    cValues;              //键值
    DWORD    cchMaxValue; 
    DWORD    cbMaxValueData; 
    DWORD    cbSecurityDescriptor;
    FILETIME ftLastWriteTime; 
    
    char subkeystr[MAX_KEY_LENGTH];
    
    DWORD i, retCode;   
     
    DWORD cchValue = MAX_VALUE_NAME;   
      
    retCode = RegQueryInfoKey(hKey,achClass,&cchClassName,NULL,&cSubKeys, &cbMaxSubKey,&cchMaxClass,&cValues,&cchMaxValue,&cbMaxValueData,&cbSecurityDescriptor,&ftLastWriteTime);   
    
    if (cSubKeys)  
    {  
        printf( "\nNumber of subkeys: %d\n", cSubKeys);          
        for (i=0; i<cSubKeys; i++)   
        {   
            cbName = MAX_KEY_LENGTH;  
            retCode = RegEnumKeyEx(hKey, i, achKey, &cbName, NULL, NULL, NULL, &ftLastWriteTime);   
            if (retCode == ERROR_SUCCESS)
            {  
                ZeroMemory(subkeystr,MAX_KEY_LENGTH);
                printf("%s\n",achKey);
            }  
        }  
    }   
} 

void main()
{
    HKEY hKey;
    char *defkey = "System\\Setup";
    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE,defkey,0, KEY_READ,&hKey) == ERROR_SUCCESS)
    {
        QueryKey(hKey);
    }
}

这样就可以读出来啦！