createfile 与 writefile

it2026-05-07  4

函数原型: 

HANDLE CreateFile(

  LPCTSTR lpFileName, //指向文件名的指针

  DWORD dwDesiredAccess, //访问模式(写/读)

  DWORD dwShareMode, //共享模式

  LPSECURITY_ATTRIBUTES lpSecurityAttributes, //指向安全属性的指针

  DWORD dwCreationDisposition, //如何创建

  DWORD dwFlagsAndAttributes, //文件属性

  HANDLE hTemplateFile //用于复制文件句柄

  );

  参数列表

  lpFileName String 要打开的文件的名字

  dwDesiredAccess Long 如果为 GENERIC_READ 表示允许对设备进行读访问;如果为 GENERIC_WRITE 表示允许对设备进行写访问(可组合使用);如果为零,表示只允许获取与一个设备有关的信息

  dwShareMode Long, 零表示不共享; FILE_SHARE_READ 和/或 FILE_SHARE_WRITE 表示允许对文件进行共享访问

  lpSecurityAttributes SECURITY_ATTRIBUTES, 指向一个SECURITY_ATTRIBUTES结构的指针,定义了文件的安全特性(如果操作系统支持的话)

  dwCreationDisposition Long,下述常数之一:

  CREATE_NEW 创建文件;如文件存在则会出错

  CREATE_ALWAYS 创建文件,会改写前一个文件

  OPEN_EXISTING 文件必须已经存在。由设备提出要求

  OPEN_ALWAYS 如文件不存在则创建它

  TRUNCATE_EXISTING 讲现有文件缩短为零长度

  dwFlagsAndAttributes Long, 一个或多个下述常数

  FILE_ATTRIBUTE_ARCHIVE 标记归档属性

  FILE_ATTRIBUTE_COMPRESSED 将文件标记为已压缩,或者标记为文件在目录中的默认压缩方式

  FILE_ATTRIBUTE_NORMAL 默认属性

  FILE_ATTRIBUTE_HIDDEN 隐藏文件或目录

  FILE_ATTRIBUTE_READONLY 文件为只读

  FILE_ATTRIBUTE_SYSTEM 文件为系统文件

  FILE_FLAG_WRITE_THROUGH 操作系统不得推迟对文件的写操作

  FILE_FLAG_OVERLAPPED 允许对文件进行重叠操作

  FILE_FLAG_NO_BUFFERING 禁止对文件进行缓冲处理。文件只能写入磁盘卷的扇区块

  FILE_FLAG_RANDOM_ACCESS 针对随机访问对文件缓冲进行优化

  FILE_FLAG_SEQUENTIAL_SCAN 针对连续访问对文件缓冲进行优化

  FILE_FLAG_DELETE_ON_CLOSE 关闭了上一次打开的句柄后,将文件删除。特别适合临时文件

  也可在Windows NT下组合使用下述常数标记:

  SECURITY_ANONYMOUS, SECURITY_IDENTIFICATION, SECURITY_IMPERSONATION, SECURITY_DELEGATION, SECURITY_CONTEXT_TRACKING, SECURITY_EFFECTIVE_ONLY

  hTemplateFile Long, 如果不为零,则指定一个文件句柄。新文件将从这个文件中复制扩展属性

返回值  如执行成功,则返回文件句柄。

  INVALID_HANDLE_VALUE表示出错,会设置GetLastError。即使函数成功,但若文件存在,且指定了CREATE_ALWAYS 或 OPEN_ALWAYS,GetLastError也会设为ERROR_ALREADY_EXISTS

(以上摘自百度百科)

实例:

1、直接在函数内指定文件地址:

void playCEwav(){CHAR *pBuffer;DWORD RSize;int fileSize = 0;int i;HANDLE hOpenFile = (HANDLE)CreateFile(L"E:\\a.text", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, NULL, NULL);if (hOpenFile == INVALID_HANDLE_VALUE){hOpenFile = NULL;MessageBoxA(NULL, "Can not open the file", "Playwav", MB_OK);}fileSize = GetFileSize(hOpenFile, NULL);pBuffer = (CHAR *) malloc(fileSize);ReadFile(hOpenFile, pBuffer, fileSize, &RSize, NULL);//可将pBuffer显示在某区域或写入另一个文件来检查读出是否正确free(pBuffer);}2、把文件地址通过参数传入:

void playwav(TCHAR * path){CHAR *pBuffer;DWORD RSize;int fileSize = 0;int i;TCHAR szPath[100];memset(szPath, 0, sizeof(szPath));_tcscpy(szPath, path);HANDLE hOpenFile = (HANDLE)CreateFile(szPath, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, NULL, NULL);if (hOpenFile == INVALID_HANDLE_VALUE){hOpenFile = NULL;MessageBoxA(NULL, "Can not open the file", "Playwav", MB_OK);}fileSize = GetFileSize(hOpenFile, NULL);pBuffer = (CHAR *) malloc(fileSize);ReadFile(hOpenFile, pBuffer, fileSize, &RSize, NULL);free(pBuffer);}

 

 

 

 

#include <windows.h>#include <stdio.h>#define BUFSIZE 4096int main(){ HANDLE hFile; HANDLE hTempFile; DWORD  dwBytesRead, dwBytesWritten, dwBufSize=BUFSIZE; char szTempName[MAX_PATH]; char buffer[BUFSIZE]; char lpPathBuffer[BUFSIZE]; // Open the existing file. hFile = CreateFile("original.txt",  // file name   GENERIC_READ,                   // open for reading   0,                              // do not share   NULL,                           // default security   OPEN_EXISTING,                  // existing file only   FILE_ATTRIBUTE_NORMAL,          // normal file   NULL);                          // no template if (hFile == INVALID_HANDLE_VALUE) {   printf("Could not open file.");  return 0; } // Get the temp path GetTempPath(dwBufSize,   // length of the buffer  lpPathBuffer);      // buffer for path // Create a temporary file. GetTempFileName(lpPathBuffer, // directory for temp files   "NEW",                    // temp file name prefix   0,                        // create unique name   szTempName);              // buffer for name hTempFile = CreateFile((LPTSTR) szTempName,  // file name   GENERIC_READ | GENERIC_WRITE, // open for read/write   0,                            // do not share   NULL,                         // default security   CREATE_ALWAYS,                // overwrite existing file  FILE_ATTRIBUTE_NORMAL,        // normal file   NULL);                        // no template if (hTempFile == INVALID_HANDLE_VALUE) {   printf("Could not create temporary file.");   return 0; } // Read 4K blocks to the buffer. // Change all characters in the buffer to upper case. // Write the buffer to the temporary file. do {  if (ReadFile(hFile, buffer, 4096,    &dwBytesRead, NULL))   {    CharUpperBuff(buffer, dwBytesRead);    WriteFile(hTempFile, buffer, dwBytesRead,     &dwBytesWritten, NULL);   } } while (dwBytesRead == BUFSIZE); // Close both files. CloseHandle(hFile); CloseHandle(hTempFile); // Move the temporary file to the new text file. if (!MoveFileEx(szTempName,   "allcaps.txt",   MOVEFILE_REPLACE_EXISTING)) {   printf("Could not move temp file.");  return 0; }}

转载于:https://www.cnblogs.com/frogchao/archive/2010/12/15/1906647.html

相关资源:使用CreateFile,ReadFile,WriteFile等API读写文件的简单类
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