通过 JNI 操作设备 /dev/input/event0 返回 -1 是为什么？

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2014-12-03 11:38:34

基本上是按文章：Android 模拟系统事件（二）来做的，可以是 open 设备 /dev/input/event0 时返回 -1.
偶试着获取了 ROOT 权限，也还是一样返回 -1；
通过 ADB Shell 浏览设备上 dev 目录下确实有：/dev/input/event0。
大家说说这是为什么啊！

附一些代码：

fd = jniClick.intCreate("/dev/input/event0", 1);



/*

 * Class:     com_hs_leozheng_ndkeumclick_jniClick

 * Method:    intCreate

 * Signature: (Ljava/lang/String;I)I

 */

JNIEXPORT jint JNICALL Java_com_hs_leozheng_ndkeumclick_jniClick_intCreate(

		JNIEnv *env, jclass thiz, jstring inputdev, jint mouse)

{

	jboolean iscopy;

	char szDev[255] = "";

	const char *pszDev = (*env)->GetStringUTFChars(env, inputdev, &iscopy);

	if (pszDev) strncpy(szDev, pszDev, 255);

	(*env)->ReleaseStringUTFChars(env, inputdev, pszDev);

	debug("intCreate call (%s)", szDev);



	struct uinput_dev dev;

	int fd_kb, aux;



	fd_kb = open(szDev, O_RDWR);

	if (fd_kb < 0) {

		debug("Can't open input device:%s(%d)", szDev,fd_kb);

		// Leo: Can't open input device:/dev/input/event0(-1)

		return -1;

	}



	memset(&dev, 0, sizeof(dev));

	strcpy(dev.name, "AndroidKeyInjector Input");

	dev.id.bustype = 0x0003;		// BUS_USB;

	dev.id.vendor  = 0x0000;

	dev.id.product = 0x0000;

	dev.id.version = 0x0000;



	if (write(fd_kb, &dev, sizeof(dev)) < 0) {

		debug("Can't write device information");

		close(fd_kb);

		return -1;

	}



	if (mouse) {

		ioctl(fd_kb, UI_SET_EVBIT, EV_REL);

		for (aux = REL_X; aux <= REL_MISC; aux++)

			ioctl(fd_kb, UI_SET_RELBIT, aux);

	}



	if (mouse) {

		ioctl(fd_kb, UI_SET_EVBIT, EV_KEY);



		for (aux = BTN_LEFT; aux <= BTN_BACK; aux++)

			ioctl(fd_kb, UI_SET_KEYBIT, aux);

	}



	ioctl(fd_kb, UI_DEV_CREATE);

	debug("intCreate success: %d",  fd_kb);

	return fd_kb;

}