CreateFile、ReadFile、WriteFile和fread、fwrite两种读写文件的方法

相关函数的使用可以查看MSDN上的说明文档。本文只提供实例。

程序需包含：#include “Windows.h”文件

方法一、采用：CreateFile、ReadFile、WriteFile

DWORD dwFileSize = 0;

	BYTE* buffer = NULL;

	HANDLE hFile = INVALID_HANDLE_VALUE;

	hFile = CreateFile("D:\12123.jpg",GENERIC_READ,
		               FILE_SHARE_READ,NULL,OPEN_EXISTING,
					   FILE_ATTRIBUTE_NORMAL,NULL);

	if (hFile == INVALID_HANDLE_VALUE)
	{
		CloseHandle(hFile);

		cout<<"Create File Failed !"<<endl;

		return 0;
	} 
	else
	{
		dwFileSize = GetFileSize(hFile,NULL);

		//LARGE_INTEGER lFileSize;

		//GetFileSizeEx(hFile,&lFileSize);//若文件长度超过0xFFFFFFFF，使用GetFileSizeEx。

		cout<<"文件大小 "<<dwFileSize<<endl;

		buffer = new BYTE[dwFileSize];

		if (buffer == NULL)
		{
			cout<<"Create buffer error !"<<endl;
	        
	      return 0;
		}

		ZeroMemory(buffer,dwFileSize);

		DWORD dwReadSize = 0,dwReadTotal = 0;

		while (dwReadTotal < dwFileSize)
		{
			ReadFile(hFile,buffer + dwReadTotal,dwFileSize - dwReadSize,&dwReadSize,NULL);

			dwReadTotal += dwReadSize;
		}

		cout<<"总共读取的文件大小 "<<dwReadTotal<<endl;
	}
	
	hFile = CreateFile("D:\222.jpg",GENERIC_WRITE,0,NULL,               
		CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);

	if (hFile == INVALID_HANDLE_VALUE)
	{
		CloseHandle(hFile);

		cout<<"Create File Failed -2 !"<<endl;

		delete []buffer;

		buffer = NULL;

		return 0;
	} 
	else
	{
		DWORD dwWriteTotal = 0,dwWriteSize = 0;

		while (dwWriteTotal < dwFileSize)
		{
			WriteFile(hFile,buffer + dwWriteTotal,dwFileSize,&dwWriteSize,NULL);

			dwWriteTotal += dwWriteSize;
		}
	}

	delete []buffer;

	buffer = NULL;

方法二、采用fread、fwrite

DWORD dwFileSize = 0;

	WIN32_FIND_DATA FileInfo;

	ZeroMemory(&FileInfo,sizeof(WIN32_FIND_DATA));

	HANDLE hFind = INVALID_HANDLE_VALUE;

	hFind = FindFirstFile("D:\12123.jpg",&FileInfo); 

	if(hFind != INVALID_HANDLE_VALUE) 
	{
		dwFileSize = FileInfo.nFileSizeLow ;
	}

	FindClose(hFind);

	BYTE* buffer = new BYTE[dwFileSize];

	if (buffer == NULL)
	{
		cout<<"Create buffer error !"<<endl;

		return 0;
	}

	ZeroMemory(buffer,dwFileSize);

	FILE *f = NULL;

	fopen_s(&f,"D:\12123.jpg","rb");

	if (f == NULL)
	{
		delete [] buffer;

		buffer = NULL;

		cout<<"fopen_s error -1 !"<<endl;

		return 0;
	} 
	else
	{
		fread(buffer,dwFileSize,1,f);
	}

	fclose(f);

	f = NULL;

	fopen_s(&f,"D:\333.jpg","wb");

	if (f == NULL)
	{
		cout<<"fopen_s error -2 !"<<endl;

		return 0;
	}

	if (fwrite(buffer,dwFileSize,1,f) < 1){
		
		cout<<"fwrite error !"<<endl;
	}

	fclose(f);

	f = NULL;