我正在使用 visual studio 2012 开发一个应用程序来检测何时在 vc++ 中插入和拔出 USB。我添加了 libusb 1.0 库，它现在是一个跨平台库。
我在尝试注册事件处理程序时遇到回调函数编译问题。
#include "detect_usb_libusb.h"
#include <QtWidgets/QApplication>
#include <time.h>
#include <stdio.h>
#include <libusb.h>
static int count = 0;
int hotplug_callback(struct libusb_context *ctx, struct libusb_device *dev,
libusb_hotplug_event event, void *user_data) {
static libusb_device_handle *handle = NULL;
struct libusb_device_descriptor desc;
int rc;
(void)libusb_get_device_descriptor(dev, &desc);
if (LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED == event) {
rc = libusb_open(dev, &handle);
if (LIBUSB_SUCCESS != rc) {
printf("Could not open USB device\n");
}
} else if (LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT == event) {
if (handle) {
libusb_close(handle);
handle = NULL;
}
} else {
printf("Unhandled event %d\n", event);
}
count++;
return 0;
}
int main (void) {
libusb_hotplug_callback_handle handle;
int rc;
libusb_init(NULL);
rc = libusb_hotplug_register_callback( NULL, (libusb_hotplug_event) (LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED |
LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT), LIBUSB_HOTPLUG_ENUMERATE,
0x2047, LIBUSB_HOTPLUG_MATCH_ANY,
LIBUSB_HOTPLUG_MATCH_ANY, hotplug_callback, NULL,
&handle);
if (LIBUSB_SUCCESS != rc) {
printf("Error creating a hotplug callback\n");
libusb_exit(NULL);
return EXIT_FAILURE;
}
while (count < 2) {
_sleep(10000);
}
libusb_hotplug_deregister_callback(NULL, handle);
libusb_exit(NULL);
return 0;
}
我从 libusb API 获得了这段代码，此时我真的迷路了。异常说:
error C2664: 'libusb_hotplug_register_callback' : cannot convert parameter 7 from 'int (__cdecl *)(libusb_context *,libusb_device *,libusb_hotplug_event,void *)' to 'libusb_hotplug_callback_fn'
但我不知道如何将我的“int (__cdecl *)”函数转换为“int( * libusb_hotplug_callback_fn)”
非常感谢
最佳答案
是这样的:static int LIBUSB_CALL hotplug_callback(libusb_context *ctx, libusb_device *dev, libusb_hotplug_event event, void *user_data) 来源:https://github.com/libusb/libusb/blob/master/examples/hotplugtest.c
关于c++ - libusb_hotplug_register_callback 不接受我的回调函数，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35159163/