通過select較高效的捕獲和處理滑鼠鍵盤事件
阿新 • • 發佈:2019-02-20
select監聽這些檔案描述符的狀態,若有一個發生變化則返回,否則阻塞。
#include <stdio.h> #include <stdlib.h> #include <linux/input.h> #include <fcntl.h> #include <sys/time.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> int main(int argc,char **argv) { int fd, retval; char buf[6]; fd_set readfds; struct timeval tv; // 開啟滑鼠裝置 fd = open( "/dev/input/mice", O_RDONLY ); // 判斷是否開啟成功 if(fd<0) { printf("Failed to open \"/dev/input/mice\".\n"); exit(1); } else { printf("open \"/dev/input/mice\" successfuly.\n"); } int fd_kb; struct input_event event_kb; fd_kb = open("/dev/input/event1", O_RDONLY); //鍵盤輸入 if(fd_kb <= 0) { printf("open device error\n"); return 0; } int fd_mouse; struct input_event event_mouse; fd_mouse = open("/dev/input/event4", O_RDONLY); //滑鼠輸入 if(fd_mouse <= 0) { printf("open device error\n"); return 0; } while(1) { // 設定最長等待時間 tv.tv_sec = 5; tv.tv_usec = 0; FD_ZERO( &readfds ); FD_SET( fd, &readfds ); FD_SET( fd_kb, &readfds ); FD_SET( fd_mouse, &readfds ); int max=fd>fd_kb?(fd>fd_mouse?fd:fd_mouse):(fd_kb>fd_mouse?fd_kb:fd_mouse); retval = select( max+1, &readfds, NULL, NULL, &tv );//有檔案描述符的狀態發生變化(變為可讀)或者超時和錯誤就返回,否則就阻塞 if(retval==0) { printf( "Time out!\n" ); }else if(retval<0){ printf( "error!\n" ); }else{ //判斷是哪個檔案描述符的狀態發生了變化,進行處理即可 //滑鼠位置 if(FD_ISSET(fd,&readfds)) { // 讀取滑鼠裝置中的資料 if(read(fd, buf, 6) <= 0) { continue; } // 打印出從滑鼠裝置中讀取到的資料 printf("Button type = %d, X = %d, Y = %d, Z = %d\n", (buf[0] & 0x07), buf[1], buf[2], buf[3]); } //鍵盤點選 if(FD_ISSET(fd_kb,&readfds)) { if(read(fd_kb, &event_kb, sizeof(event_kb)) == sizeof(event_kb)) { if (event_kb.type == EV_KEY) { //if (event_kb.value == 0 || event_kb.value == 1)//1表示按下,0表示釋放,會檢測到兩次 if (event_kb.value == 1)//鍵按下 { //printf("key %d %s\n", event_kb.code, (event_kb.value) ? "Pressed" : "Released"); if(event_kb.code == KEY_ESC) break; if(event_kb.code == KEY_Q) printf("q\n"); if(event_kb.code == KEY_W) printf("w\n"); if(event_kb.code == KEY_E) printf("e\n"); if(event_kb.code == KEY_R) printf("r\n"); } } } } //滑鼠點選 if(FD_ISSET(fd_mouse,&readfds)) { if(read(fd_mouse, &event_mouse, sizeof(event_mouse)) == sizeof(event_mouse)) { if(event_mouse.type = EV_REL) { if(event_mouse.code == REL_WHEEL) printf("REL_WHEEL %d\n", event_mouse.value);//-1表示下滑,1表示上滑 } if(event_mouse.code == BTN_LEFT && event_mouse.value==1)//左鍵按下,1表示按下,0表示釋放。不然會檢測到兩次 printf("left down: %d\n", event_mouse.code); if(event_mouse.code == BTN_RIGHT && event_mouse.value==1) printf("right down: %d\n", event_mouse.code); if(event_mouse.code == BTN_MIDDLE && event_mouse.value==1) printf("middle down: %d\n", event_mouse.code); } } } } close(fd); close(fd_kb); close(fd_mouse); return 0; }