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