Question

程序以递归方式导航给定文件夹，为文件夹创建注册表，但在执行RegSetValueEx函数后，注册表中没有任何事情发生，我应该更改什么？我的意思是该程序工作完美但注册表中RegSetValuesEx函数没有任何变化，只是RegCreateKeys运行良好。

#include "stdafx.h"
#include <windows.h>
#include <tchar.h> 
#include <stdio.h>
#include <strsafe.h>
#include <iostream>
using namespace std;
#define DEFAULT_KEY_DIR "HKEY_CURRENT_USER"
#define DEFAULT_KEY_SUBDIR "Software\\CSSO"
#define DEFAULT_DIRECTORY "D:\\Example"
char xPath[2048] = "Software\\CSSO";

bool ListDirectoryContents(const char *sDir)  
{
WIN32_FIND_DATA fdFile;
HANDLE hFind = NULL;
LARGE_INTEGER filesize;
DWORD return_value;
char sPath[2048];
HKEY hKey;


sprintf(sPath, "%s\\*", sDir);

if ((hFind = FindFirstFile(sPath, &fdFile)) == INVALID_HANDLE_VALUE)
{
    printf("Path not found: [%s]\n", sDir);
    return false;
}

do
{

    if (strcmp(fdFile.cFileName, ".") != 0
        && strcmp(fdFile.cFileName, "..") != 0)
    {

        sprintf(sPath, "%s\\%s", sDir, fdFile.cFileName);


        if (fdFile.dwFileAttributes &FILE_ATTRIBUTE_DIRECTORY)
        {

            printf("%s\n", sPath);
            memset(&xPath[0], 0, sizeof(xPath));
            strcpy(xPath, DEFAULT_KEY_SUBDIR);
            int j = strlen(DEFAULT_KEY_SUBDIR);
            for (int i = strlen(DEFAULT_DIRECTORY); i < strlen(sPath); i++)
            {
                xPath[j] = sPath[i];
                j++;
            }


                RegCreateKeyEx(
                HKEY_CURRENT_USER,
                xPath,
                0, 0, REG_OPTION_NON_VOLATILE,
                KEY_ALL_ACCESS, 0, &hKey, 0
            );

            ListDirectoryContents(sPath); //Recursion, I love it!
        }
        else {
            filesize.LowPart = fdFile.nFileSizeLow;
            filesize.HighPart = fdFile.nFileSizeHigh;
            _tprintf(TEXT("%s  %ld bytes\n"),sPath, filesize.QuadPart);

            return_value = RegSetValueEx(
                hKey,
                fdFile.cFileName, 0,
                REG_DWORD,
                (BYTE*)filesize.QuadPart,
                strlen(sPath)
            );
        }
    }
} while (FindNextFile(hFind, &fdFile)); 

FindClose(hFind); 

return true;
}

int main()
{
ListDirectoryContents("D:\\Example");
system("PAUSE");
return 0;
}

Answer 1

上面的代码正在经历递归循环，它向注册表中添加了大量垃圾。不建议这样做。

return_value = RegSetValueEx(
            hKey,
            fdFile.cFileName, 0,
            REG_DWORD,
            (BYTE*)filesize.QuadPart,
            strlen(sPath))

(BYTE*)filesize.QuadPart错了。它类似于写作：

BYTE* ptr = (BYTE*)123;

这会创建一个指向内存地址123的指针，我们不允许这样做。你的意思是写(BYTE*)&filesize.QuadPart。

假设您要编写文件大小，请使用REG_QWORD代替REG_DWORD。使用sizeof(filesize.QuadPart)代替strlen(path)。

if (ERROR_SUCCESS != RegSetValueEx(hKey, fdFile.cFileName, 0, REG_QWORD, 
    (BYTE*)&filesize.QuadPart, sizeof(filesize.QuadPart))
{
    printf("RegSetValueEx error\n");    
}

但是，您应该使用注册表仅添加初始化数据。如果您有大量数据，则保存到文件，或者只将其保存在内存中。

Answer 2

我弄清楚我做错了什么，谢谢你们的答案，我会发布最终的代码，也许会帮助别人。

#include <iostream>
#include <sstream>
#include <string>
#include <typeinfo>
using namespace std;

//Class Template Stack declaration
template <class T>
class TemplateStack {
public:
    typedef T type;
    TemplateStack()
    {
        max_size_ = 50;
        TopOfStack = 0;
        data_ = new T[max_size_];
    } //Default Constructor taking no parameters
    void push(T element)
    {
        if (TopOfStack == max_size_)
            throw string("Stack's underlying storage is overflow");
        TopOfStack++;
        data_[TopOfStack] = element;
    }
      void pop() {
            if (TopOfStack == -1)
                  throw string("Stack is empty");
            TopOfStack--;
      }


      T top() {
            if (TopOfStack == -1)
                  throw string("Stack is empty");
            return data_[TopOfStack];
     }

private:
    int TopOfStack; //Generic data type for the top element of stack
    size_t max_size_;
    T* data_;
};

 //Function to Evauluate the Postfix notation expresion
int PostfixEvaulation(string input){
    //string input;
    int operand1, operand2, result,number;
    TemplateStack<char>operation;
    stringstream temp;
    int i=0;
    while (i < input.length())
    {
        if (isdigit(input[i]))
        {
            operation.push(input[i]);
        }
        else
        {
          operand2 = operation.top();
          temp << operation.top();
          operation.pop();
          operand1 = operation.top();
          temp << operation.top();
          operation.pop();
          switch(operand1,operand2)
          {
                  case '+': result=operand1 + operand2;
                  break;
                  case '-': result=operand1 - operand2;
                  break;
                  case '*': result=operand1 * operand2;
                  break;
                  case '/': result=operand1 / operand2;
                  break;
        }
        operation.push(result);
        }
        i++;
    }
    cout << "The result is: "<<temp.str()<<endl;
    //cin.ignore(numeric_limits<streamsize>::max(), '\n');
    return 0;
}


//Function to return precedence of operators
int prec(char c)
{
    if(c == '^')
    return 3;
    else if(c == '*' || c == '/')
    return 2;
    else if(c == '+' || c == '-')
    return 1;
    else
    return -1;
}

//Function: Convert Infix to Postfix
void infixToPostfix(string s)
{
    TemplateStack<char> st;
    st.push('N');
    int l = s.length();
    string ns;
    for (int i = 0; i < l; i++) {
        // If the scanned character is an operand, add it to output string.
        if ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z')) {
            ns += s[i];
        }
        // If the scanned character is an ‘(‘, push it to the stack.
        else if (s[i] == '(') {

            st.push('(');
        }
        // If the scanned character is an ‘)’, pop and to output string from the stack
        // until an ‘(‘ is encountered.
        else if (s[i] == ')') {
            while (st.top() != 'N' && st.top() != '(') {
                char c = st.top();
                st.pop();
                ns += c;
            }
            if (st.top() == '(') {
                char c = st.top();
                st.pop();
            }
        }
        //If an operator is scanned
        else {
            while (st.top() != 'N' && prec(s[i]) <= prec(st.top())) {
                char c = st.top();
                st.pop();
                ns += c;
            }
            st.push(s[i]);
        }
    }
    //Pop all the remaining elements from the stack
    while (st.top() != 'N') {
        char c = st.top();
        st.pop();
        ns += c;
    }
    cout << "Here is the ns variable: "<< ns << endl;
    PostfixEvaulation(ns);//Call the PostFixEvaluationFunction with the ns (postfix notation) variab
}

 //Function: User inputs Expression
void GetInput(){
    string input;
    cout << "Enter Infix Expression: ";
    getline(cin, input);
    infixToPostfix(input);
}

int main()
{
    GetInput();
}

C，Windows API以递归方式导航子目录

2 个答案: