#include <tchar.h>
#include <windows.h>
#include <iostream>
#include <string>
using namespace std;
#define CreateFile  CreateFileA

std::string Encode(const char* Data, int DataByte)
{
    //編碼表  
    const char EncodeTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
 
";
    //返回值  
    string strEncode;
    unsigned char Tmp[4] = { 0 };
    int LineLength = 0;
    for (int i = 0; i < (int)(DataByte / 3); i++)
    {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        Tmp[3] = *Data++;
        strEncode += EncodeTable[Tmp[1] >> 2];
        strEncode += EncodeTable[((Tmp[1
 
] << 4) | (Tmp[2] >> 4)) & 0x3F];
        strEncode += EncodeTable[((Tmp[2] << 2) | (Tmp[3] >> 6)) & 0x3F];
        strEncode += EncodeTable[Tmp[3] & 0x3F];
        if (LineLength += 4, LineLength == 76) { strEncode += "\r\n"; LineLength = 0; }
    }
    //對剩餘資料進行編碼  
    int
 
 Mod = DataByte % 3;
    if (Mod == 1)
    {
        Tmp[1] = *Data++;
        strEncode += EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode += EncodeTable[((Tmp[1] & 0x03) << 4)];
        strEncode += "==";
    }
    else if (Mod == 2)
    {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        strEncode += EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode += EncodeTable[((Tmp[1] & 0x03) << 4) | ((Tmp[2] & 0xF0) >> 4)];
        strEncode += EncodeTable[((Tmp[2] & 0x0F) << 2)];
        strEncode += "=";
    }

    return strEncode;
}

std::string Decode(const char* Data, int DataByte, int& OutByte)
{
    //解碼錶  
    const char DecodeTable[] =
    {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        62, // '+'  
        0, 0, 0,
        63, // '/'  
        52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'  
        0, 0, 0, 0, 0, 0, 0,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
        13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'  
        0, 0, 0, 0, 0, 0,
        26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
        39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'  
    };
    //返回值  
    string strDecode;
    int nValue;
    int i = 0;
    while (i < DataByte)
    {
        if (*Data != '\r' && *Data != '\n')
        {
            nValue = DecodeTable[*Data++] << 18;
            nValue += DecodeTable[*Data++] << 12;
            strDecode += (nValue & 0x00FF0000) >> 16;
            OutByte++;
            if (*Data != '=')
            {
                nValue += DecodeTable[*Data++] << 6;
                strDecode += (nValue & 0x0000FF00) >> 8;
                OutByte++;
                if (*Data != '=')
                {
                    nValue += DecodeTable[*Data++];
                    strDecode += nValue & 0x000000FF;
                    OutByte++;
                }
            }
            i += 4;
        }
        else// 回車換行,跳過  
        {
            Data++;
            i++;
        }
    }
    return strDecode;
}


//以下是讀寫圖片的呼叫程式碼：
bool ReadPhotoFile(std::string& strFileName, std::string &strData)
{
    HANDLE hFile;
    hFile = CreateFile(strFileName.c_str(), GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

    if (hFile == INVALID_HANDLE_VALUE)
    {
        return false;
    }

    DWORD dFileSize = GetFileSize(hFile, NULL);
    char * pBuffer = new char[dFileSize + 1];

    if (pBuffer == NULL)
        return false;

    memset(pBuffer, 0, dFileSize);

    DWORD dReadSize(0);
    if (!ReadFile(hFile, pBuffer, dFileSize, &dReadSize, NULL))
    {
        delete[]pBuffer;
        CloseHandle(hFile);
        return false;
    }


    strData = "";
    strData = Encode((const char*)pBuffer, dReadSize);

    delete[]pBuffer;
    CloseHandle(hFile);
    return true;
}

bool WritePhotoFile(std::string& strFileName, std::string &strData)
{
    HANDLE hFile;
    hFile = CreateFile(strFileName.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

    if (hFile == INVALID_HANDLE_VALUE)
    {
        return false;
    }


    int datalen(0);
    DWORD dwritelen(0);
    std::string strdcode = Decode(strData.data(), strData.size(), datalen);
    if (!WriteFile(hFile, strdcode.data(), datalen, &dwritelen, NULL))
    {
        CloseHandle(hFile);
        return false;
    }
    CloseHandle(hFile);
    return true;
}

int main()
{
    //圖片轉base64
    string path("C:\\Users\\X\\Desktop\\test\\name.png");  //圖片路徑
    string data;    //轉換後的字串
    ReadPhotoFile(path, data);

    //base64轉圖片
    string strfilename("C:\\Users\\X\\Desktop\\test\\123.bmp");  //轉換後的的圖片的路徑和格式（可改為其他格式）
    WritePhotoFile(strfilename, data);


    return 0;
}