LVGL8 的 evdev 驱动改成这样，但是长按回车键，不能跳出当前选中的widgets

memory · 2024-11-04 21:07:24

            } else if(drv->type == LV_INDEV_TYPE_ENCODER) {
                switch(in.code) {
                    case KEY_UP: //模拟编码器向上滚
                        data->state = 0;
                        if(in.value == 1) {
                            data->enc_diff = -1;
                        } else {
                            data->enc_diff = 0;
                        }
                        printf("data->state=%d, data->enc_diff=%d ........\n", data->state, data->enc_diff);
                        break;
                    case KEY_DOWN: //模拟编码器向下滚
                        data->state = 0;
                        if(in.value == 1) {
                            data->enc_diff = 1;
                        } else {
                            data->enc_diff = 0;
                        }
                        printf("data->state=%d, data->enc_diff=%d ........\n", data->state, data->enc_diff);
                        break;
                    case KEY_ENTER: //模拟编码器按下
                        data->state = in.value;
                        data->enc_diff = 0;
                        printf("data->state=%d, data->enc_diff=%d ........\n", data->state, data->enc_diff);
                        break;
                }

memory · 2024-11-04 21:07:27

memory · 2024-11-04 23:24:01

跟踪了一下代码，长按编码器按键使当前按键失焦的代码在

lv_indev.c

/**
 * Process a new point from LV_INDEV_TYPE_ENCODER input device
 * @param i pointer to an input device
 * @param data pointer to the data read from the input device
 */
static void indev_encoder_proc(lv_indev_t * i, lv_indev_data_t * data)
{
    /*Button press happened*/
    if(data->state == LV_INDEV_STATE_PRESSED && last_state == LV_INDEV_STATE_RELEASED) {
    }
    /*Pressing*/
    else if(data->state == LV_INDEV_STATE_PRESSED && last_state == LV_INDEV_STATE_PRESSED) {
        /*Long press*/
        if(i->proc.long_pr_sent == 0 && lv_tick_elaps(i->proc.pr_timestamp) > i->driver->long_press_time) {
            //初次长按处理
        }
        /*Long press repeated time has elapsed?*/
        else if(i->proc.long_pr_sent != 0 && lv_tick_elaps(i->proc.longpr_rep_timestamp) > i->driver->long_press_repeat_time) {
            //一直长按处理
        }
    }
}

memory · 2024-11-05 15:30:29

大概找到问题了，linux 的 event 设备，按键一直按住，也只触发一次。

https://elinux.org/images/9/93/Evtest.c

/*
 * $Id: evtest.c,v 1.23 2005/02/06 13:51:42 vojtech Exp $
 *
 *  Copyright (c) 1999-2000 Vojtech Pavlik
 *
 *  Event device test program
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or 
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * 
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <stdint.h>

#include <linux/input.h>

#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>

#ifndef EV_SYN
#define EV_SYN 0
#endif

char *events[EV_MAX + 1] = {
	[0 ... EV_MAX] = NULL,
	[EV_SYN] = "Sync",			[EV_KEY] = "Key",
	[EV_REL] = "Relative",			[EV_ABS] = "Absolute",
	[EV_MSC] = "Misc",			[EV_LED] = "LED",
	[EV_SND] = "Sound",			[EV_REP] = "Repeat",
	[EV_FF] = "ForceFeedback",		[EV_PWR] = "Power",
	[EV_FF_STATUS] = "ForceFeedbackStatus",
};

char *keys[KEY_MAX + 1] = {
	[0 ... KEY_MAX] = NULL,
	[KEY_RESERVED] = "Reserved",		[KEY_ESC] = "Esc",
	[KEY_1] = "1",				[KEY_2] = "2",
	[KEY_3] = "3",				[KEY_4] = "4",
	[KEY_5] = "5",				[KEY_6] = "6",
	[KEY_7] = "7",				[KEY_8] = "8",
	[KEY_9] = "9",				[KEY_0] = "0",
	[KEY_MINUS] = "Minus",			[KEY_EQUAL] = "Equal",
	[KEY_BACKSPACE] = "Backspace",		[KEY_TAB] = "Tab",
	[KEY_Q] = "Q",				[KEY_W] = "W",
	[KEY_E] = "E",				[KEY_R] = "R",
	[KEY_T] = "T",				[KEY_Y] = "Y",
	[KEY_U] = "U",				[KEY_I] = "I",
	[KEY_O] = "O",				[KEY_P] = "P",
	[KEY_LEFTBRACE] = "LeftBrace",		[KEY_RIGHTBRACE] = "RightBrace",
	[KEY_ENTER] = "Enter",			[KEY_LEFTCTRL] = "LeftControl",
	[KEY_A] = "A",				[KEY_S] = "S",
	[KEY_D] = "D",				[KEY_F] = "F",
	[KEY_G] = "G",				[KEY_H] = "H",
	[KEY_J] = "J",				[KEY_K] = "K",
	[KEY_L] = "L",				[KEY_SEMICOLON] = "Semicolon",
	[KEY_APOSTROPHE] = "Apostrophe",	[KEY_GRAVE] = "Grave",
	[KEY_LEFTSHIFT] = "LeftShift",		[KEY_BACKSLASH] = "BackSlash",
	[KEY_Z] = "Z",				[KEY_X] = "X",
	[KEY_C] = "C",				[KEY_V] = "V",
	[KEY_B] = "B",				[KEY_N] = "N",
	[KEY_M] = "M",				[KEY_COMMA] = "Comma",
	[KEY_DOT] = "Dot",			[KEY_SLASH] = "Slash",
	[KEY_RIGHTSHIFT] = "RightShift",	[KEY_KPASTERISK] = "KPAsterisk",
	[KEY_LEFTALT] = "LeftAlt",		[KEY_SPACE] = "Space",
	[KEY_CAPSLOCK] = "CapsLock",		[KEY_F1] = "F1",
	[KEY_F2] = "F2",			[KEY_F3] = "F3",
	[KEY_F4] = "F4",			[KEY_F5] = "F5",
	[KEY_F6] = "F6",			[KEY_F7] = "F7",
	[KEY_F8] = "F8",			[KEY_F9] = "F9",
	[KEY_F10] = "F10",			[KEY_NUMLOCK] = "NumLock",
	[KEY_SCROLLLOCK] = "ScrollLock",	[KEY_KP7] = "KP7",
	[KEY_KP8] = "KP8",			[KEY_KP9] = "KP9",
	[KEY_KPMINUS] = "KPMinus",		[KEY_KP4] = "KP4",
	[KEY_KP5] = "KP5",			[KEY_KP6] = "KP6",
	[KEY_KPPLUS] = "KPPlus",		[KEY_KP1] = "KP1",
	[KEY_KP2] = "KP2",			[KEY_KP3] = "KP3",
	[KEY_KP0] = "KP0",			[KEY_KPDOT] = "KPDot",
	[KEY_ZENKAKUHANKAKU] = "Zenkaku/Hankaku", [KEY_102ND] = "102nd",
	[KEY_F11] = "F11",			[KEY_F12] = "F12",
	[KEY_RO] = "RO",			[KEY_KATAKANA] = "Katakana",
	[KEY_HIRAGANA] = "HIRAGANA",		[KEY_HENKAN] = "Henkan",
	[KEY_KATAKANAHIRAGANA] = "Katakana/Hiragana", [KEY_MUHENKAN] = "Muhenkan",
	[KEY_KPJPCOMMA] = "KPJpComma",		[KEY_KPENTER] = "KPEnter",
	[KEY_RIGHTCTRL] = "RightCtrl",		[KEY_KPSLASH] = "KPSlash",
	[KEY_SYSRQ] = "SysRq",			[KEY_RIGHTALT] = "RightAlt",
	[KEY_LINEFEED] = "LineFeed",		[KEY_HOME] = "Home",
	[KEY_UP] = "Up",			[KEY_PAGEUP] = "PageUp",
	[KEY_LEFT] = "Left",			[KEY_RIGHT] = "Right",
	[KEY_END] = "End",			[KEY_DOWN] = "Down",
	[KEY_PAGEDOWN] = "PageDown",		[KEY_INSERT] = "Insert",
	[KEY_DELETE] = "Delete",		[KEY_MACRO] = "Macro",
	[KEY_MUTE] = "Mute",			[KEY_VOLUMEDOWN] = "VolumeDown",
	[KEY_VOLUMEUP] = "VolumeUp",		[KEY_POWER] = "Power",
	[KEY_KPEQUAL] = "KPEqual",		[KEY_KPPLUSMINUS] = "KPPlusMinus",
	[KEY_PAUSE] = "Pause",			[KEY_KPCOMMA] = "KPComma",
	[KEY_HANGUEL] = "Hanguel",		[KEY_HANJA] = "Hanja",
	[KEY_YEN] = "Yen",			[KEY_LEFTMETA] = "LeftMeta",
	[KEY_RIGHTMETA] = "RightMeta",		[KEY_COMPOSE] = "Compose",
	[KEY_STOP] = "Stop",			[KEY_AGAIN] = "Again",
	[KEY_PROPS] = "Props",			[KEY_UNDO] = "Undo",
	[KEY_FRONT] = "Front",			[KEY_COPY] = "Copy",
	[KEY_OPEN] = "Open",			[KEY_PASTE] = "Paste",
	[KEY_FIND] = "Find",			[KEY_CUT] = "Cut",
	[KEY_HELP] = "Help",			[KEY_MENU] = "Menu",
	[KEY_CALC] = "Calc",			[KEY_SETUP] = "Setup",
	[KEY_SLEEP] = "Sleep",			[KEY_WAKEUP] = "WakeUp",
	[KEY_FILE] = "File",			[KEY_SENDFILE] = "SendFile",
	[KEY_DELETEFILE] = "DeleteFile",	[KEY_XFER] = "X-fer",
	[KEY_PROG1] = "Prog1",			[KEY_PROG2] = "Prog2",
	[KEY_WWW] = "WWW",			[KEY_MSDOS] = "MSDOS",
	[KEY_COFFEE] = "Coffee",		[KEY_DIRECTION] = "Direction",
	[KEY_CYCLEWINDOWS] = "CycleWindows",	[KEY_MAIL] = "Mail",
	[KEY_BOOKMARKS] = "Bookmarks",		[KEY_COMPUTER] = "Computer",
	[KEY_BACK] = "Back",			[KEY_FORWARD] = "Forward",
	[KEY_CLOSECD] = "CloseCD",		[KEY_EJECTCD] = "EjectCD",
	[KEY_EJECTCLOSECD] = "EjectCloseCD",	[KEY_NEXTSONG] = "NextSong",
	[KEY_PLAYPAUSE] = "PlayPause",		[KEY_PREVIOUSSONG] = "PreviousSong",
	[KEY_STOPCD] = "StopCD",		[KEY_RECORD] = "Record",
	[KEY_REWIND] = "Rewind",		[KEY_PHONE] = "Phone",
	[KEY_ISO] = "ISOKey",			[KEY_CONFIG] = "Config",
	[KEY_HOMEPAGE] = "HomePage",		[KEY_REFRESH] = "Refresh",
	[KEY_EXIT] = "Exit",			[KEY_MOVE] = "Move",
	[KEY_EDIT] = "Edit",			[KEY_SCROLLUP] = "ScrollUp",
	[KEY_SCROLLDOWN] = "ScrollDown",	[KEY_KPLEFTPAREN] = "KPLeftParenthesis",
	[KEY_KPRIGHTPAREN] = "KPRightParenthesis", [KEY_F13] = "F13",
	[KEY_F14] = "F14",			[KEY_F15] = "F15",
	[KEY_F16] = "F16",			[KEY_F17] = "F17",
	[KEY_F18] = "F18",			[KEY_F19] = "F19",
	[KEY_F20] = "F20",			[KEY_F21] = "F21",
	[KEY_F22] = "F22",			[KEY_F23] = "F23",
	[KEY_F24] = "F24",			[KEY_PLAYCD] = "PlayCD",
	[KEY_PAUSECD] = "PauseCD",		[KEY_PROG3] = "Prog3",
	[KEY_PROG4] = "Prog4",			[KEY_SUSPEND] = "Suspend",
	[KEY_CLOSE] = "Close",			[KEY_PLAY] = "Play",
	[KEY_FASTFORWARD] = "Fast Forward",	[KEY_BASSBOOST] = "Bass Boost",
	[KEY_PRINT] = "Print",			[KEY_HP] = "HP",
	[KEY_CAMERA] = "Camera",		[KEY_SOUND] = "Sound",
	[KEY_QUESTION] = "Question",		[KEY_EMAIL] = "Email",
	[KEY_CHAT] = "Chat",			[KEY_SEARCH] = "Search",
	[KEY_CONNECT] = "Connect",		[KEY_FINANCE] = "Finance",
	[KEY_SPORT] = "Sport",			[KEY_SHOP] = "Shop",
	[KEY_ALTERASE] = "Alternate Erase",	[KEY_CANCEL] = "Cancel",
	[KEY_BRIGHTNESSDOWN] = "Brightness down", [KEY_BRIGHTNESSUP] = "Brightness up",
	[KEY_MEDIA] = "Media",			[KEY_UNKNOWN] = "Unknown",
	[BTN_0] = "Btn0",			[BTN_1] = "Btn1",
	[BTN_2] = "Btn2",			[BTN_3] = "Btn3",
	[BTN_4] = "Btn4",			[BTN_5] = "Btn5",
	[BTN_6] = "Btn6",			[BTN_7] = "Btn7",
	[BTN_8] = "Btn8",			[BTN_9] = "Btn9",
	[BTN_LEFT] = "LeftBtn",			[BTN_RIGHT] = "RightBtn",
	[BTN_MIDDLE] = "MiddleBtn",		[BTN_SIDE] = "SideBtn",
	[BTN_EXTRA] = "ExtraBtn",		[BTN_FORWARD] = "ForwardBtn",
	[BTN_BACK] = "BackBtn",			[BTN_TASK] = "TaskBtn",
	[BTN_TRIGGER] = "Trigger",		[BTN_THUMB] = "ThumbBtn",
	[BTN_THUMB2] = "ThumbBtn2",		[BTN_TOP] = "TopBtn",
	[BTN_TOP2] = "TopBtn2",			[BTN_PINKIE] = "PinkieBtn",
	[BTN_BASE] = "BaseBtn",			[BTN_BASE2] = "BaseBtn2",
	[BTN_BASE3] = "BaseBtn3",		[BTN_BASE4] = "BaseBtn4",
	[BTN_BASE5] = "BaseBtn5",		[BTN_BASE6] = "BaseBtn6",
	[BTN_DEAD] = "BtnDead",			[BTN_A] = "BtnA",
	[BTN_B] = "BtnB",			[BTN_C] = "BtnC",
	[BTN_X] = "BtnX",			[BTN_Y] = "BtnY",
	[BTN_Z] = "BtnZ",			[BTN_TL] = "BtnTL",
	[BTN_TR] = "BtnTR",			[BTN_TL2] = "BtnTL2",
	[BTN_TR2] = "BtnTR2",			[BTN_SELECT] = "BtnSelect",
	[BTN_START] = "BtnStart",		[BTN_MODE] = "BtnMode",
	[BTN_THUMBL] = "BtnThumbL",		[BTN_THUMBR] = "BtnThumbR",
	[BTN_TOOL_PEN] = "ToolPen",		[BTN_TOOL_RUBBER] = "ToolRubber",
	[BTN_TOOL_BRUSH] = "ToolBrush",		[BTN_TOOL_PENCIL] = "ToolPencil",
	[BTN_TOOL_AIRBRUSH] = "ToolAirbrush",	[BTN_TOOL_FINGER] = "ToolFinger",
	[BTN_TOOL_MOUSE] = "ToolMouse",		[BTN_TOOL_LENS] = "ToolLens",
	[BTN_TOUCH] = "Touch",			[BTN_STYLUS] = "Stylus",
	[BTN_STYLUS2] = "Stylus2",		[BTN_TOOL_DOUBLETAP] = "Tool Doubletap",
	[BTN_TOOL_TRIPLETAP] = "Tool Tripletap", [BTN_GEAR_DOWN] = "WheelBtn",
	[BTN_GEAR_UP] = "Gear up",		[KEY_OK] = "Ok",
	[KEY_SELECT] = "Select",		[KEY_GOTO] = "Goto",
	[KEY_CLEAR] = "Clear",			[KEY_POWER2] = "Power2",
	[KEY_OPTION] = "Option",		[KEY_INFO] = "Info",
	[KEY_TIME] = "Time",			[KEY_VENDOR] = "Vendor",
	[KEY_ARCHIVE] = "Archive",		[KEY_PROGRAM] = "Program",
	[KEY_CHANNEL] = "Channel",		[KEY_FAVORITES] = "Favorites",
	[KEY_EPG] = "EPG",			[KEY_PVR] = "PVR",
	[KEY_MHP] = "MHP",			[KEY_LANGUAGE] = "Language",
	[KEY_TITLE] = "Title",			[KEY_SUBTITLE] = "Subtitle",
	[KEY_ANGLE] = "Angle",			[KEY_ZOOM] = "Zoom",
	[KEY_MODE] = "Mode",			[KEY_KEYBOARD] = "Keyboard",
	[KEY_SCREEN] = "Screen",		[KEY_PC] = "PC",
	[KEY_TV] = "TV",			[KEY_TV2] = "TV2",
	[KEY_VCR] = "VCR",			[KEY_VCR2] = "VCR2",
	[KEY_SAT] = "Sat",			[KEY_SAT2] = "Sat2",
	[KEY_CD] = "CD",			[KEY_TAPE] = "Tape",
	[KEY_RADIO] = "Radio",			[KEY_TUNER] = "Tuner",
	[KEY_PLAYER] = "Player",		[KEY_TEXT] = "Text",
	[KEY_DVD] = "DVD",			[KEY_AUX] = "Aux",
	[KEY_MP3] = "MP3",			[KEY_AUDIO] = "Audio",
	[KEY_VIDEO] = "Video",			[KEY_DIRECTORY] = "Directory",
	[KEY_LIST] = "List",			[KEY_MEMO] = "Memo",
	[KEY_CALENDAR] = "Calendar",		[KEY_RED] = "Red",
	[KEY_GREEN] = "Green",			[KEY_YELLOW] = "Yellow",
	[KEY_BLUE] = "Blue",			[KEY_CHANNELUP] = "ChannelUp",
	[KEY_CHANNELDOWN] = "ChannelDown",	[KEY_FIRST] = "First",
	[KEY_LAST] = "Last",			[KEY_AB] = "AB",
	[KEY_NEXT] = "Next",			[KEY_RESTART] = "Restart",
	[KEY_SLOW] = "Slow",			[KEY_SHUFFLE] = "Shuffle",
	[KEY_BREAK] = "Break",			[KEY_PREVIOUS] = "Previous",
	[KEY_DIGITS] = "Digits",		[KEY_TEEN] = "TEEN",
	[KEY_TWEN] = "TWEN",			[KEY_DEL_EOL] = "Delete EOL",
	[KEY_DEL_EOS] = "Delete EOS",		[KEY_INS_LINE] = "Insert line",
	[KEY_DEL_LINE] = "Delete line",
};

char *absval[5] = { "Value", "Min  ", "Max  ", "Fuzz ", "Flat " };

char *relatives[REL_MAX + 1] = {
	[0 ... REL_MAX] = NULL,
	[REL_X] = "X",			[REL_Y] = "Y",
	[REL_Z] = "Z",			[REL_HWHEEL] = "HWheel",
	[REL_DIAL] = "Dial",		[REL_WHEEL] = "Wheel", 
	[REL_MISC] = "Misc",	
};

char *absolutes[ABS_MAX + 1] = {
	[0 ... ABS_MAX] = NULL,
	[ABS_X] = "X",			[ABS_Y] = "Y",
	[ABS_Z] = "Z",			[ABS_RX] = "Rx",
	[ABS_RY] = "Ry",		[ABS_RZ] = "Rz",
	[ABS_THROTTLE] = "Throttle",	[ABS_RUDDER] = "Rudder",
	[ABS_WHEEL] = "Wheel",		[ABS_GAS] = "Gas",
	[ABS_BRAKE] = "Brake",		[ABS_HAT0X] = "Hat0X",
	[ABS_HAT0Y] = "Hat0Y",		[ABS_HAT1X] = "Hat1X",
	[ABS_HAT1Y] = "Hat1Y",		[ABS_HAT2X] = "Hat2X",
	[ABS_HAT2Y] = "Hat2Y",		[ABS_HAT3X] = "Hat3X",
	[ABS_HAT3Y] = "Hat 3Y",		[ABS_PRESSURE] = "Pressure",
	[ABS_DISTANCE] = "Distance",	[ABS_TILT_X] = "XTilt",
	[ABS_TILT_Y] = "YTilt",		[ABS_TOOL_WIDTH] = "Tool Width",
	[ABS_VOLUME] = "Volume",	[ABS_MISC] = "Misc",
};

char *misc[MSC_MAX + 1] = {
	[ 0 ... MSC_MAX] = NULL,
	[MSC_SERIAL] = "Serial",	[MSC_PULSELED] = "Pulseled",
	[MSC_GESTURE] = "Gesture",	[MSC_RAW] = "RawData",
	[MSC_SCAN] = "ScanCode",
};

char *leds[LED_MAX + 1] = {
	[0 ... LED_MAX] = NULL,
	[LED_NUML] = "NumLock",		[LED_CAPSL] = "CapsLock", 
	[LED_SCROLLL] = "ScrollLock",	[LED_COMPOSE] = "Compose",
	[LED_KANA] = "Kana",		[LED_SLEEP] = "Sleep", 
	[LED_SUSPEND] = "Suspend",	[LED_MUTE] = "Mute",
	[LED_MISC] = "Misc",
};

char *repeats[REP_MAX + 1] = {
	[0 ... REP_MAX] = NULL,
	[REP_DELAY] = "Delay",		[REP_PERIOD] = "Period"
};

char *sounds[SND_MAX + 1] = {
	[0 ... SND_MAX] = NULL,
	[SND_CLICK] = "Click",		[SND_BELL] = "Bell",
	[SND_TONE] = "Tone"
};

char **names[EV_MAX + 1] = {
	[0 ... EV_MAX] = NULL,
	[EV_SYN] = events,			[EV_KEY] = keys,
	[EV_REL] = relatives,			[EV_ABS] = absolutes,
	[EV_MSC] = misc,			[EV_LED] = leds,
	[EV_SND] = sounds,			[EV_REP] = repeats,
};

#define BITS_PER_LONG (sizeof(long) * 8)
#define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
#define OFF(x)  ((x)%BITS_PER_LONG)
#define BIT(x)  (1UL<<OFF(x))
#define LONG(x) ((x)/BITS_PER_LONG)
#define test_bit(bit, array)	((array[LONG(bit)] >> OFF(bit)) & 1)

int main (int argc, char **argv)
{
	int fd, rd, i, j, k;
	struct input_event ev[64];
	int version;
	unsigned short id[4];
	unsigned long bit[EV_MAX][NBITS(KEY_MAX)];
	char name[256] = "Unknown";
	int abs[5];

	if (argc < 2) {
		printf("Usage: evtest /dev/input/eventX\n");
		printf("Where X = input device number\n");
		return 1;
	}

	if ((fd = open(argv[argc - 1], O_RDONLY)) < 0) {
		perror("evtest");
		return 1;
	}

	if (ioctl(fd, EVIOCGVERSION, &version)) {
		perror("evtest: can't get version");
		return 1;
	}

	printf("Input driver version is %d.%d.%d\n",
		version >> 16, (version >> 8) & 0xff, version & 0xff);

	ioctl(fd, EVIOCGID, id);
	printf("Input device ID: bus 0x%x vendor 0x%x product 0x%x version 0x%x\n",
		id[ID_BUS], id[ID_VENDOR], id[ID_PRODUCT], id[ID_VERSION]);

	ioctl(fd, EVIOCGNAME(sizeof(name)), name);
	printf("Input device name: \"%s\"\n", name);

	memset(bit, 0, sizeof(bit));
	ioctl(fd, EVIOCGBIT(0, EV_MAX), bit[0]);
	printf("Supported events:\n");

	for (i = 0; i < EV_MAX; i++)
		if (test_bit(i, bit[0])) {
			printf("  Event type %d (%s)\n", i, events[i] ? events[i] : "?");
			if (!i) continue;
			ioctl(fd, EVIOCGBIT(i, KEY_MAX), bit[i]);
			for (j = 0; j < KEY_MAX; j++) 
				if (test_bit(j, bit[i])) {
					printf("    Event code %d (%s)\n", j, names[i] ? (names[i][j] ? names[i][j] : "?") : "?");
					if (i == EV_ABS) {
						ioctl(fd, EVIOCGABS(j), abs);
						for (k = 0; k < 5; k++)
							if ((k < 3) || abs[k])
								printf("      %s %6d\n", absval[k], abs[k]);
					}
				}
		}
		

	printf("Testing ... (interrupt to exit)\n");

	while (1) {
		rd = read(fd, ev, sizeof(struct input_event) * 64);

		if (rd < (int) sizeof(struct input_event)) {
			printf("yyy\n");
			perror("\nevtest: error reading");
			return 1;
		}

		for (i = 0; i < rd / sizeof(struct input_event); i++)

			if (ev[i].type == EV_SYN) {
				printf("Event: time %ld.%06ld, -------------- %s ------------\n",
					ev[i].time.tv_sec, ev[i].time.tv_usec, ev[i].code ? "Config Sync" : "Report Sync" );
			} else if (ev[i].type == EV_MSC && (ev[i].code == MSC_RAW || ev[i].code == MSC_SCAN)) {
				printf("Event: time %ld.%06ld, type %d (%s), code %d (%s), value %02x\n",
					ev[i].time.tv_sec, ev[i].time.tv_usec, ev[i].type,
					events[ev[i].type] ? events[ev[i].type] : "?",
					ev[i].code,
					names[ev[i].type] ? (names[ev[i].type][ev[i].code] ? names[ev[i].type][ev[i].code] : "?") : "?",
					ev[i].value);
			} else {
				printf("Event: time %ld.%06ld, type %d (%s), code %d (%s), value %d\n",
					ev[i].time.tv_sec, ev[i].time.tv_usec, ev[i].type,
					events[ev[i].type] ? events[ev[i].type] : "?",
					ev[i].code,
					names[ev[i].type] ? (names[ev[i].type][ev[i].code] ? names[ev[i].type][ev[i].code] : "?") : "?",
					ev[i].value);
			}	

	}
}

上面是阻塞式代码，然后我改成非阻塞式(O_NONBLOCK)代码：

/*
 * $Id: evtest.c,v 1.23 2005/02/06 13:51:42 vojtech Exp $
 *
 *  Copyright (c) 1999-2000 Vojtech Pavlik
 *
 *  Event device test program
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or 
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * 
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <stdint.h>

#include <linux/input.h>

#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>

#ifndef EV_SYN
#define EV_SYN 0
#endif

char *events[EV_MAX + 1] = {
	[0 ... EV_MAX] = NULL,
	[EV_SYN] = "Sync",			[EV_KEY] = "Key",
	[EV_REL] = "Relative",			[EV_ABS] = "Absolute",
	[EV_MSC] = "Misc",			[EV_LED] = "LED",
	[EV_SND] = "Sound",			[EV_REP] = "Repeat",
	[EV_FF] = "ForceFeedback",		[EV_PWR] = "Power",
	[EV_FF_STATUS] = "ForceFeedbackStatus",
};

char *keys[KEY_MAX + 1] = {
	[0 ... KEY_MAX] = NULL,
	[KEY_RESERVED] = "Reserved",		[KEY_ESC] = "Esc",
	[KEY_1] = "1",				[KEY_2] = "2",
	[KEY_3] = "3",				[KEY_4] = "4",
	[KEY_5] = "5",				[KEY_6] = "6",
	[KEY_7] = "7",				[KEY_8] = "8",
	[KEY_9] = "9",				[KEY_0] = "0",
	[KEY_MINUS] = "Minus",			[KEY_EQUAL] = "Equal",
	[KEY_BACKSPACE] = "Backspace",		[KEY_TAB] = "Tab",
	[KEY_Q] = "Q",				[KEY_W] = "W",
	[KEY_E] = "E",				[KEY_R] = "R",
	[KEY_T] = "T",				[KEY_Y] = "Y",
	[KEY_U] = "U",				[KEY_I] = "I",
	[KEY_O] = "O",				[KEY_P] = "P",
	[KEY_LEFTBRACE] = "LeftBrace",		[KEY_RIGHTBRACE] = "RightBrace",
	[KEY_ENTER] = "Enter",			[KEY_LEFTCTRL] = "LeftControl",
	[KEY_A] = "A",				[KEY_S] = "S",
	[KEY_D] = "D",				[KEY_F] = "F",
	[KEY_G] = "G",				[KEY_H] = "H",
	[KEY_J] = "J",				[KEY_K] = "K",
	[KEY_L] = "L",				[KEY_SEMICOLON] = "Semicolon",
	[KEY_APOSTROPHE] = "Apostrophe",	[KEY_GRAVE] = "Grave",
	[KEY_LEFTSHIFT] = "LeftShift",		[KEY_BACKSLASH] = "BackSlash",
	[KEY_Z] = "Z",				[KEY_X] = "X",
	[KEY_C] = "C",				[KEY_V] = "V",
	[KEY_B] = "B",				[KEY_N] = "N",
	[KEY_M] = "M",				[KEY_COMMA] = "Comma",
	[KEY_DOT] = "Dot",			[KEY_SLASH] = "Slash",
	[KEY_RIGHTSHIFT] = "RightShift",	[KEY_KPASTERISK] = "KPAsterisk",
	[KEY_LEFTALT] = "LeftAlt",		[KEY_SPACE] = "Space",
	[KEY_CAPSLOCK] = "CapsLock",		[KEY_F1] = "F1",
	[KEY_F2] = "F2",			[KEY_F3] = "F3",
	[KEY_F4] = "F4",			[KEY_F5] = "F5",
	[KEY_F6] = "F6",			[KEY_F7] = "F7",
	[KEY_F8] = "F8",			[KEY_F9] = "F9",
	[KEY_F10] = "F10",			[KEY_NUMLOCK] = "NumLock",
	[KEY_SCROLLLOCK] = "ScrollLock",	[KEY_KP7] = "KP7",
	[KEY_KP8] = "KP8",			[KEY_KP9] = "KP9",
	[KEY_KPMINUS] = "KPMinus",		[KEY_KP4] = "KP4",
	[KEY_KP5] = "KP5",			[KEY_KP6] = "KP6",
	[KEY_KPPLUS] = "KPPlus",		[KEY_KP1] = "KP1",
	[KEY_KP2] = "KP2",			[KEY_KP3] = "KP3",
	[KEY_KP0] = "KP0",			[KEY_KPDOT] = "KPDot",
	[KEY_ZENKAKUHANKAKU] = "Zenkaku/Hankaku", [KEY_102ND] = "102nd",
	[KEY_F11] = "F11",			[KEY_F12] = "F12",
	[KEY_RO] = "RO",			[KEY_KATAKANA] = "Katakana",
	[KEY_HIRAGANA] = "HIRAGANA",		[KEY_HENKAN] = "Henkan",
	[KEY_KATAKANAHIRAGANA] = "Katakana/Hiragana", [KEY_MUHENKAN] = "Muhenkan",
	[KEY_KPJPCOMMA] = "KPJpComma",		[KEY_KPENTER] = "KPEnter",
	[KEY_RIGHTCTRL] = "RightCtrl",		[KEY_KPSLASH] = "KPSlash",
	[KEY_SYSRQ] = "SysRq",			[KEY_RIGHTALT] = "RightAlt",
	[KEY_LINEFEED] = "LineFeed",		[KEY_HOME] = "Home",
	[KEY_UP] = "Up",			[KEY_PAGEUP] = "PageUp",
	[KEY_LEFT] = "Left",			[KEY_RIGHT] = "Right",
	[KEY_END] = "End",			[KEY_DOWN] = "Down",
	[KEY_PAGEDOWN] = "PageDown",		[KEY_INSERT] = "Insert",
	[KEY_DELETE] = "Delete",		[KEY_MACRO] = "Macro",
	[KEY_MUTE] = "Mute",			[KEY_VOLUMEDOWN] = "VolumeDown",
	[KEY_VOLUMEUP] = "VolumeUp",		[KEY_POWER] = "Power",
	[KEY_KPEQUAL] = "KPEqual",		[KEY_KPPLUSMINUS] = "KPPlusMinus",
	[KEY_PAUSE] = "Pause",			[KEY_KPCOMMA] = "KPComma",
	[KEY_HANGUEL] = "Hanguel",		[KEY_HANJA] = "Hanja",
	[KEY_YEN] = "Yen",			[KEY_LEFTMETA] = "LeftMeta",
	[KEY_RIGHTMETA] = "RightMeta",		[KEY_COMPOSE] = "Compose",
	[KEY_STOP] = "Stop",			[KEY_AGAIN] = "Again",
	[KEY_PROPS] = "Props",			[KEY_UNDO] = "Undo",
	[KEY_FRONT] = "Front",			[KEY_COPY] = "Copy",
	[KEY_OPEN] = "Open",			[KEY_PASTE] = "Paste",
	[KEY_FIND] = "Find",			[KEY_CUT] = "Cut",
	[KEY_HELP] = "Help",			[KEY_MENU] = "Menu",
	[KEY_CALC] = "Calc",			[KEY_SETUP] = "Setup",
	[KEY_SLEEP] = "Sleep",			[KEY_WAKEUP] = "WakeUp",
	[KEY_FILE] = "File",			[KEY_SENDFILE] = "SendFile",
	[KEY_DELETEFILE] = "DeleteFile",	[KEY_XFER] = "X-fer",
	[KEY_PROG1] = "Prog1",			[KEY_PROG2] = "Prog2",
	[KEY_WWW] = "WWW",			[KEY_MSDOS] = "MSDOS",
	[KEY_COFFEE] = "Coffee",		[KEY_DIRECTION] = "Direction",
	[KEY_CYCLEWINDOWS] = "CycleWindows",	[KEY_MAIL] = "Mail",
	[KEY_BOOKMARKS] = "Bookmarks",		[KEY_COMPUTER] = "Computer",
	[KEY_BACK] = "Back",			[KEY_FORWARD] = "Forward",
	[KEY_CLOSECD] = "CloseCD",		[KEY_EJECTCD] = "EjectCD",
	[KEY_EJECTCLOSECD] = "EjectCloseCD",	[KEY_NEXTSONG] = "NextSong",
	[KEY_PLAYPAUSE] = "PlayPause",		[KEY_PREVIOUSSONG] = "PreviousSong",
	[KEY_STOPCD] = "StopCD",		[KEY_RECORD] = "Record",
	[KEY_REWIND] = "Rewind",		[KEY_PHONE] = "Phone",
	[KEY_ISO] = "ISOKey",			[KEY_CONFIG] = "Config",
	[KEY_HOMEPAGE] = "HomePage",		[KEY_REFRESH] = "Refresh",
	[KEY_EXIT] = "Exit",			[KEY_MOVE] = "Move",
	[KEY_EDIT] = "Edit",			[KEY_SCROLLUP] = "ScrollUp",
	[KEY_SCROLLDOWN] = "ScrollDown",	[KEY_KPLEFTPAREN] = "KPLeftParenthesis",
	[KEY_KPRIGHTPAREN] = "KPRightParenthesis", [KEY_F13] = "F13",
	[KEY_F14] = "F14",			[KEY_F15] = "F15",
	[KEY_F16] = "F16",			[KEY_F17] = "F17",
	[KEY_F18] = "F18",			[KEY_F19] = "F19",
	[KEY_F20] = "F20",			[KEY_F21] = "F21",
	[KEY_F22] = "F22",			[KEY_F23] = "F23",
	[KEY_F24] = "F24",			[KEY_PLAYCD] = "PlayCD",
	[KEY_PAUSECD] = "PauseCD",		[KEY_PROG3] = "Prog3",
	[KEY_PROG4] = "Prog4",			[KEY_SUSPEND] = "Suspend",
	[KEY_CLOSE] = "Close",			[KEY_PLAY] = "Play",
	[KEY_FASTFORWARD] = "Fast Forward",	[KEY_BASSBOOST] = "Bass Boost",
	[KEY_PRINT] = "Print",			[KEY_HP] = "HP",
	[KEY_CAMERA] = "Camera",		[KEY_SOUND] = "Sound",
	[KEY_QUESTION] = "Question",		[KEY_EMAIL] = "Email",
	[KEY_CHAT] = "Chat",			[KEY_SEARCH] = "Search",
	[KEY_CONNECT] = "Connect",		[KEY_FINANCE] = "Finance",
	[KEY_SPORT] = "Sport",			[KEY_SHOP] = "Shop",
	[KEY_ALTERASE] = "Alternate Erase",	[KEY_CANCEL] = "Cancel",
	[KEY_BRIGHTNESSDOWN] = "Brightness down", [KEY_BRIGHTNESSUP] = "Brightness up",
	[KEY_MEDIA] = "Media",			[KEY_UNKNOWN] = "Unknown",
	[BTN_0] = "Btn0",			[BTN_1] = "Btn1",
	[BTN_2] = "Btn2",			[BTN_3] = "Btn3",
	[BTN_4] = "Btn4",			[BTN_5] = "Btn5",
	[BTN_6] = "Btn6",			[BTN_7] = "Btn7",
	[BTN_8] = "Btn8",			[BTN_9] = "Btn9",
	[BTN_LEFT] = "LeftBtn",			[BTN_RIGHT] = "RightBtn",
	[BTN_MIDDLE] = "MiddleBtn",		[BTN_SIDE] = "SideBtn",
	[BTN_EXTRA] = "ExtraBtn",		[BTN_FORWARD] = "ForwardBtn",
	[BTN_BACK] = "BackBtn",			[BTN_TASK] = "TaskBtn",
	[BTN_TRIGGER] = "Trigger",		[BTN_THUMB] = "ThumbBtn",
	[BTN_THUMB2] = "ThumbBtn2",		[BTN_TOP] = "TopBtn",
	[BTN_TOP2] = "TopBtn2",			[BTN_PINKIE] = "PinkieBtn",
	[BTN_BASE] = "BaseBtn",			[BTN_BASE2] = "BaseBtn2",
	[BTN_BASE3] = "BaseBtn3",		[BTN_BASE4] = "BaseBtn4",
	[BTN_BASE5] = "BaseBtn5",		[BTN_BASE6] = "BaseBtn6",
	[BTN_DEAD] = "BtnDead",			[BTN_A] = "BtnA",
	[BTN_B] = "BtnB",			[BTN_C] = "BtnC",
	[BTN_X] = "BtnX",			[BTN_Y] = "BtnY",
	[BTN_Z] = "BtnZ",			[BTN_TL] = "BtnTL",
	[BTN_TR] = "BtnTR",			[BTN_TL2] = "BtnTL2",
	[BTN_TR2] = "BtnTR2",			[BTN_SELECT] = "BtnSelect",
	[BTN_START] = "BtnStart",		[BTN_MODE] = "BtnMode",
	[BTN_THUMBL] = "BtnThumbL",		[BTN_THUMBR] = "BtnThumbR",
	[BTN_TOOL_PEN] = "ToolPen",		[BTN_TOOL_RUBBER] = "ToolRubber",
	[BTN_TOOL_BRUSH] = "ToolBrush",		[BTN_TOOL_PENCIL] = "ToolPencil",
	[BTN_TOOL_AIRBRUSH] = "ToolAirbrush",	[BTN_TOOL_FINGER] = "ToolFinger",
	[BTN_TOOL_MOUSE] = "ToolMouse",		[BTN_TOOL_LENS] = "ToolLens",
	[BTN_TOUCH] = "Touch",			[BTN_STYLUS] = "Stylus",
	[BTN_STYLUS2] = "Stylus2",		[BTN_TOOL_DOUBLETAP] = "Tool Doubletap",
	[BTN_TOOL_TRIPLETAP] = "Tool Tripletap", [BTN_GEAR_DOWN] = "WheelBtn",
	[BTN_GEAR_UP] = "Gear up",		[KEY_OK] = "Ok",
	[KEY_SELECT] = "Select",		[KEY_GOTO] = "Goto",
	[KEY_CLEAR] = "Clear",			[KEY_POWER2] = "Power2",
	[KEY_OPTION] = "Option",		[KEY_INFO] = "Info",
	[KEY_TIME] = "Time",			[KEY_VENDOR] = "Vendor",
	[KEY_ARCHIVE] = "Archive",		[KEY_PROGRAM] = "Program",
	[KEY_CHANNEL] = "Channel",		[KEY_FAVORITES] = "Favorites",
	[KEY_EPG] = "EPG",			[KEY_PVR] = "PVR",
	[KEY_MHP] = "MHP",			[KEY_LANGUAGE] = "Language",
	[KEY_TITLE] = "Title",			[KEY_SUBTITLE] = "Subtitle",
	[KEY_ANGLE] = "Angle",			[KEY_ZOOM] = "Zoom",
	[KEY_MODE] = "Mode",			[KEY_KEYBOARD] = "Keyboard",
	[KEY_SCREEN] = "Screen",		[KEY_PC] = "PC",
	[KEY_TV] = "TV",			[KEY_TV2] = "TV2",
	[KEY_VCR] = "VCR",			[KEY_VCR2] = "VCR2",
	[KEY_SAT] = "Sat",			[KEY_SAT2] = "Sat2",
	[KEY_CD] = "CD",			[KEY_TAPE] = "Tape",
	[KEY_RADIO] = "Radio",			[KEY_TUNER] = "Tuner",
	[KEY_PLAYER] = "Player",		[KEY_TEXT] = "Text",
	[KEY_DVD] = "DVD",			[KEY_AUX] = "Aux",
	[KEY_MP3] = "MP3",			[KEY_AUDIO] = "Audio",
	[KEY_VIDEO] = "Video",			[KEY_DIRECTORY] = "Directory",
	[KEY_LIST] = "List",			[KEY_MEMO] = "Memo",
	[KEY_CALENDAR] = "Calendar",		[KEY_RED] = "Red",
	[KEY_GREEN] = "Green",			[KEY_YELLOW] = "Yellow",
	[KEY_BLUE] = "Blue",			[KEY_CHANNELUP] = "ChannelUp",
	[KEY_CHANNELDOWN] = "ChannelDown",	[KEY_FIRST] = "First",
	[KEY_LAST] = "Last",			[KEY_AB] = "AB",
	[KEY_NEXT] = "Next",			[KEY_RESTART] = "Restart",
	[KEY_SLOW] = "Slow",			[KEY_SHUFFLE] = "Shuffle",
	[KEY_BREAK] = "Break",			[KEY_PREVIOUS] = "Previous",
	[KEY_DIGITS] = "Digits",		[KEY_TEEN] = "TEEN",
	[KEY_TWEN] = "TWEN",			[KEY_DEL_EOL] = "Delete EOL",
	[KEY_DEL_EOS] = "Delete EOS",		[KEY_INS_LINE] = "Insert line",
	[KEY_DEL_LINE] = "Delete line",
};

char *absval[5] = { "Value", "Min  ", "Max  ", "Fuzz ", "Flat " };

char *relatives[REL_MAX + 1] = {
	[0 ... REL_MAX] = NULL,
	[REL_X] = "X",			[REL_Y] = "Y",
	[REL_Z] = "Z",			[REL_HWHEEL] = "HWheel",
	[REL_DIAL] = "Dial",		[REL_WHEEL] = "Wheel", 
	[REL_MISC] = "Misc",	
};

char *absolutes[ABS_MAX + 1] = {
	[0 ... ABS_MAX] = NULL,
	[ABS_X] = "X",			[ABS_Y] = "Y",
	[ABS_Z] = "Z",			[ABS_RX] = "Rx",
	[ABS_RY] = "Ry",		[ABS_RZ] = "Rz",
	[ABS_THROTTLE] = "Throttle",	[ABS_RUDDER] = "Rudder",
	[ABS_WHEEL] = "Wheel",		[ABS_GAS] = "Gas",
	[ABS_BRAKE] = "Brake",		[ABS_HAT0X] = "Hat0X",
	[ABS_HAT0Y] = "Hat0Y",		[ABS_HAT1X] = "Hat1X",
	[ABS_HAT1Y] = "Hat1Y",		[ABS_HAT2X] = "Hat2X",
	[ABS_HAT2Y] = "Hat2Y",		[ABS_HAT3X] = "Hat3X",
	[ABS_HAT3Y] = "Hat 3Y",		[ABS_PRESSURE] = "Pressure",
	[ABS_DISTANCE] = "Distance",	[ABS_TILT_X] = "XTilt",
	[ABS_TILT_Y] = "YTilt",		[ABS_TOOL_WIDTH] = "Tool Width",
	[ABS_VOLUME] = "Volume",	[ABS_MISC] = "Misc",
};

char *misc[MSC_MAX + 1] = {
	[ 0 ... MSC_MAX] = NULL,
	[MSC_SERIAL] = "Serial",	[MSC_PULSELED] = "Pulseled",
	[MSC_GESTURE] = "Gesture",	[MSC_RAW] = "RawData",
	[MSC_SCAN] = "ScanCode",
};

char *leds[LED_MAX + 1] = {
	[0 ... LED_MAX] = NULL,
	[LED_NUML] = "NumLock",		[LED_CAPSL] = "CapsLock", 
	[LED_SCROLLL] = "ScrollLock",	[LED_COMPOSE] = "Compose",
	[LED_KANA] = "Kana",		[LED_SLEEP] = "Sleep", 
	[LED_SUSPEND] = "Suspend",	[LED_MUTE] = "Mute",
	[LED_MISC] = "Misc",
};

char *repeats[REP_MAX + 1] = {
	[0 ... REP_MAX] = NULL,
	[REP_DELAY] = "Delay",		[REP_PERIOD] = "Period"
};

char *sounds[SND_MAX + 1] = {
	[0 ... SND_MAX] = NULL,
	[SND_CLICK] = "Click",		[SND_BELL] = "Bell",
	[SND_TONE] = "Tone"
};

char **names[EV_MAX + 1] = {
	[0 ... EV_MAX] = NULL,
	[EV_SYN] = events,			[EV_KEY] = keys,
	[EV_REL] = relatives,			[EV_ABS] = absolutes,
	[EV_MSC] = misc,			[EV_LED] = leds,
	[EV_SND] = sounds,			[EV_REP] = repeats,
};

#define BITS_PER_LONG (sizeof(long) * 8)
#define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
#define OFF(x)  ((x)%BITS_PER_LONG)
#define BIT(x)  (1UL<<OFF(x))
#define LONG(x) ((x)/BITS_PER_LONG)
#define test_bit(bit, array)	((array[LONG(bit)] >> OFF(bit)) & 1)

int main (int argc, char **argv)
{
	int fd, rd, i, j, k;
	struct input_event ev[64];
	int version;
	unsigned short id[4];
	unsigned long bit[EV_MAX][NBITS(KEY_MAX)];
	char name[256] = "Unknown";
	int abs[5];

	if (argc < 2) {
		printf("Usage: evtest /dev/input/eventX\n");
		printf("Where X = input device number\n");
		return 1;
	}

	if ((fd = open(argv[argc - 1], O_RDONLY | O_NONBLOCK)) < 0) {
		perror("evtest");
		return 1;
	}

	if (ioctl(fd, EVIOCGVERSION, &version)) {
		perror("evtest: can't get version");
		return 1;
	}

	printf("Input driver version is %d.%d.%d\n",
		version >> 16, (version >> 8) & 0xff, version & 0xff);

	ioctl(fd, EVIOCGID, id);
	printf("Input device ID: bus 0x%x vendor 0x%x product 0x%x version 0x%x\n",
		id[ID_BUS], id[ID_VENDOR], id[ID_PRODUCT], id[ID_VERSION]);

	ioctl(fd, EVIOCGNAME(sizeof(name)), name);
	printf("Input device name: \"%s\"\n", name);

	memset(bit, 0, sizeof(bit));
	ioctl(fd, EVIOCGBIT(0, EV_MAX), bit[0]);
	printf("Supported events:\n");

	for (i = 0; i < EV_MAX; i++)
		if (test_bit(i, bit[0])) {
			printf("  Event type %d (%s)\n", i, events[i] ? events[i] : "?");
			if (!i) continue;
			ioctl(fd, EVIOCGBIT(i, KEY_MAX), bit[i]);
			for (j = 0; j < KEY_MAX; j++) 
				if (test_bit(j, bit[i])) {
					printf("    Event code %d (%s)\n", j, names[i] ? (names[i][j] ? names[i][j] : "?") : "?");
					if (i == EV_ABS) {
						ioctl(fd, EVIOCGABS(j), abs);
						for (k = 0; k < 5; k++)
							if ((k < 3) || abs[k])
								printf("      %s %6d\n", absval[k], abs[k]);
					}
				}
		}
		

	printf("Testing ... (interrupt to exit)\n");

	while (1) {
		rd = read(fd, ev, sizeof(struct input_event) * 64);

		if (rd < (int) sizeof(struct input_event)) {
			//printf("yyy\n");
			//perror("\nevtest: error reading");
			//return 1;
			usleep(20*1000);
			continue;
		}

		for (i = 0; i < rd / sizeof(struct input_event); i++)

			if (ev[i].type == EV_SYN) {
				printf("Event: time %ld.%06ld, -------------- %s ------------\n",
					ev[i].time.tv_sec, ev[i].time.tv_usec, ev[i].code ? "Config Sync" : "Report Sync" );
			} else if (ev[i].type == EV_MSC && (ev[i].code == MSC_RAW || ev[i].code == MSC_SCAN)) {
				printf("Event: time %ld.%06ld, type %d (%s), code %d (%s), value %02x\n",
					ev[i].time.tv_sec, ev[i].time.tv_usec, ev[i].type,
					events[ev[i].type] ? events[ev[i].type] : "?",
					ev[i].code,
					names[ev[i].type] ? (names[ev[i].type][ev[i].code] ? names[ev[i].type][ev[i].code] : "?") : "?",
					ev[i].value);
			} else {
				printf("Event: time %ld.%06ld, type %d (%s), code %d (%s), value %d\n",
					ev[i].time.tv_sec, ev[i].time.tv_usec, ev[i].type,
					events[ev[i].type] ? events[ev[i].type] : "?",
					ev[i].code,
					names[ev[i].type] ? (names[ev[i].type][ev[i].code] ? names[ev[i].type][ev[i].code] : "?") : "?",
					ev[i].value);
			}	

	}
}

还是一样，只要按键一直按住，也只触发一次。

# chmod +x /tmp/evtest  && /tmp/evtest /dev/input/event2
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "gpiokey"
Supported events:
  Event type 0 (Sync)
  Event type 1 (Key)
    Event code 28 (Enter)
    Event code 103 (Up)
    Event code 105 (Left)
    Event code 106 (Right)
    Event code 108 (Down)
    Event code 158 (Back)
Testing ... (interrupt to exit)
Event: time 80621.024553, type 1 (Key), code 28 (Enter), value 1
Event: time 80621.024553, -------------- Report Sync ------------
Event: time 80621.136503, type 1 (Key), code 28 (Enter), value 0
Event: time 80621.136503, -------------- Report Sync ------------
Event: time 80621.972507, type 1 (Key), code 28 (Enter), value 1
Event: time 80621.972507, -------------- Report Sync ------------
Event: time 80623.652503, type 1 (Key), code 28 (Enter), value 0
Event: time 80623.652503, -------------- Report Sync ------------
Event: time 80624.228508, type 1 (Key), code 105 (Left), value 1
Event: time 80624.228508, -------------- Report Sync ------------

在 Linux 中，输入设备（如键盘、鼠标等）通过 /dev/input/eventX 文件生成事件。
这些事件通常只会在按键状态发生变化时生成，即按键按下和按键释放时。

具体来说：

按键按下：生成一个 EV_KEY 事件，值为 1。
按键释放：生成一个 EV_KEY 事件，值为 0。

按键保持按下状态：不会持续生成事件。
这种设计是为了减少不必要的事件流量，提高系统的效率。然而，这导致了一个问题：如果你需要检测按键是否一直被按下，你需要在应用程序中实现额外的逻辑来跟踪按键的状态。

如何实现持续检测按键状态
为了实现持续检测按键是否一直被按下，你可以使用以下方法：

① 记录按键按下时间：在按键首次按下时记录当前时间。
② 定期检查按键状态：在按键按下后，定期检查按键是否仍然处于按下状态。
③ 处理长按事件：如果按键保持按下状态超过一定时间阈值，则触发长按事件。

memory · 2024-11-05 16:03:01

    static int g_encoder_status = 0; //记住按键是否被按下，1：按下，0：抬起

    if(drv->type == LV_INDEV_TYPE_ENCODER) {
    if (g_encoder_status == 1) {
        data->state = 1;
        data->enc_diff = 0;
        }
    }

            } else if(drv->type == LV_INDEV_TYPE_ENCODER) {

                switch(in.code) {
                    case KEY_UP: //模拟编码器向上滚
                        data->state = 0;
                        if(in.value == 1) {
                            data->enc_diff = -1;
                        } else {
                            data->enc_diff = 0;
                        }

                        break;
                    case KEY_DOWN: //模拟编码器向下滚
                        data->state = 0;
                        if(in.value == 1) {
                            data->enc_diff = 1;
                        } else {
                            data->enc_diff = 0;
                        }

                        break;
                    case KEY_ENTER: //模拟编码器按下
						g_encoder_status = in.value;
                        data->state = in.value;
                        data->enc_diff = 0;

                        break;
                }

加入一个全局变量解决这个问题。

WhyCan Forum(哇酷开发者社区)

楼主 # 2024-11-04 21:07:24 分享评论

LVGL8 的 evdev 驱动改成这样，但是长按回车键，不能跳出当前选中的widgets

楼主 #1 2024-11-04 21:07:27 分享评论

Re: LVGL8 的 evdev 驱动改成这样，但是长按回车键，不能跳出当前选中的widgets

楼主 #2 2024-11-04 23:24:01 分享评论

Re: LVGL8 的 evdev 驱动改成这样，但是长按回车键，不能跳出当前选中的widgets

楼主 #3 2024-11-05 15:30:29 分享评论

Re: LVGL8 的 evdev 驱动改成这样，但是长按回车键，不能跳出当前选中的widgets

楼主 #4 2024-11-05 16:03:01 分享评论

Re: LVGL8 的 evdev 驱动改成这样，但是长按回车键，不能跳出当前选中的widgets

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