目录

一、环境

二、问题

三、解决方法

一、环境

硬件：Jetson Xavier NX 套件

系统：Ubuntu 20.4

QT ：QT5.12.9

二、问题

        我在使用hidapi读写光机设备时，在将hidapi引入工程，进行编译时，提示大量的libusb方法undefined reference 未找到。

:-1: error: hidapi.o: in function `hid_init':/projector/hidapi.c:499: error: undefined reference to `libusb_init'
-1: error: hidapi.o: in function `hid_exit':/projector/hidapi.c:514: error: undefined reference to `libusb_exit'
:-1: error: hidapi.o: in function `hid_enumerate':/projector/hidapi.c:535: error: undefined reference to `libusb_get_device_list'
:-1: error:/projector/hidapi.c:544: undefined reference to `libusb_get_device_descriptor'
:-1: error: /projector/hidapi.c:548: undefined reference to `libusb_get_active_config_descriptor'
:-1: error: /projector/hidapi.c:550: undefined reference to `libusb_get_config_descriptor'
:-1: error: /projector/hidapi.c:579: undefined reference to `libusb_open'
:-1: error: /projector/hidapi.c:658: undefined reference to `libusb_close'
:-1: error: /projector/hidapi.c:673: undefined reference to `libusb_free_config_descriptor'
:-1: error: /projector/hidapi.c:677: undefined reference to `libusb_free_device_list'
:-1: error: hidapi.o: in function `make_path':
/projector/hidapi.c:484: error: undefined reference to `libusb_get_bus_number'
:-1: error: /projector/hidapi.c:485: undefined reference to `libusb_get_device_address'
:-1: error: linker command failed with exit code 1 (use -v to see invocation)
 

三、解决方法

在QT 工程中添加库引用   LIBS += -lusb-1.0  或 LIBS += -lusb 即可，注意，libusb库 1.23版本以前的添加-lusb

unix:!macx {
    LIBS += \
        -lusb-1.0
}

重新清理、编译工程错误消失。

如果还是提示错误，请检查系统是否安装 libusb；在终端输入以下两条命令安装libusb库

sudo apt-get install libusb-1.0-0-dev
sudo apt-get install libusb-dev

参考：c++ - Libusb undefined reference to - Stack Overflow

OK！

        至此，问题解决。