ReadFile ReadFileEx异步操作 控制台程序

#include <windows.h>#include <stdio.h>#define BUFFER_SIZE512//假设该文件大于或等于BUFFER_SIZE#define DEVICE_NAME"test.dat"int main(){HANDLE hDevice = CreateFile("test.dat",GENERIC_READ | GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,//此处设置FILE_FLAG_OVERLAPPEDNULL );if (hDevice == INVALID_HANDLE_VALUE) {printf("Read Error\n");return 1;}UCHAR buffer[BUFFER_SIZE];DWORD dwRead;//初始化overlap使其内部全部为零OVERLAPPED overlap={0};//创建overlap事件overlap.hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);//这里没有设置OVERLAP参数，因此是异步操作ReadFile(hDevice,buffer,BUFFER_SIZE,&dwRead,&overlap);//做一些其他操作，这些操作会与读设备并行执行//等待读设备结束WaitForSingleObject(overlap.hEvent,INFINITE);CloseHandle(hDevice);return 0;}

#include <windows.h>#include <stdio.h>#define DEVICE_NAME"test.dat"#define BUFFER_SIZE512//假设该文件大于或等于BUFFER_SIZEVOID CALLBACK MyFileIOCompletionRoutine(  DWORD dwErrorCode,                // 对于此次操作返回的状态  DWORD dwNumberOfBytesTransfered,  // 告诉已经操作了多少字节,也就是在IRP里的Infomation  LPOVERLAPPED lpOverlapped         // 这个数据结构){printf("IO operation end!\n");}int main(){HANDLE hDevice = CreateFile("test.dat",GENERIC_READ | GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,//此处设置FILE_FLAG_OVERLAPPEDNULL );if (hDevice == INVALID_HANDLE_VALUE) {printf("Read Error\n");return 1;}UCHAR buffer[BUFFER_SIZE];//初始化overlap使其内部全部为零//不用初始化事件!!OVERLAPPED overlap={0};//这里没有设置OVERLAP参数，因此是异步操作ReadFileEx(hDevice, buffer, BUFFER_SIZE,&overlap,MyFileIOCompletionRoutine);//做一些其他操作，这些操作会与读设备并行执行//进入alterableSleepEx(0,TRUE);CloseHandle(hDevice);return 0;}