如何在Linux下利用Libusb与HID USB设备通信！

         由于公司的产品，导致我在Linux下写usb通信的代码出现了许多的问题，最后发现这些设备只能通过控制传输来操作设备，所以后面的问题就迎刃而解了。现在贴上当时在QT下写的代码，以防日后再碰到此类问题的时候翻查。

         还有在QT下使用libusb库的时候一定要在（项目名.pro）文件加上：

INCLUDEPATH += /usr/include/libusb-1.0
LIBS += -L"/usr/lib/x86_64-linux-gnu" -lusb-1.0

否则程序无法找到该库的路径。

   libusb_device **devs;
    libusb_device_handle *dev_handle;
    libusb_context *ctx=NULL;
    struct  libusb_device_descriptor desc;
    int r;
    ssize_t cnt;
    r=libusb_init(&ctx);
    if(r<0)
    {
        //printf("init error");
        QMessageBox::about(this,"haha","initialerror");
        return ;
    }
    libusb_set_debug(ctx,3);
    //cnt=libusb_get_device_list(ctx,&devs);
    dev_handle=libusb_open_device_with_vid_pid(ctx,VID,PID);
    if(dev_handle==NULL)
        QMessageBox::about(this,"haha","open my dev error");
    else
        QMessageBox::about(this,"haha","open my dev success");
    //libusb_free_device_list(devs,1);
    if(libusb_kernel_driver_active(dev_handle,0)==1)
    {
        QMessageBox::about(this,"haha","kernel driver active");
        if(libusb_detach_kernel_driver(dev_handle,0)==0)
            QMessageBox::about(this,"haha","kernel driver detached");
    }
    r=libusb_claim_interface(dev_handle,0);
    if(r<0)
    {
        QMessageBox::about(this,"haha","cannot claim interface");
        return ;
    }
    QMessageBox::about(this,"haha","claimed interface");
    // start use this usb
    unsigned char dataOut[0x30]={0};
    dataOut[0]=0x00;
    dataOut[1]=0x02;
    dataOut[2]=0x08;
    dataOut[3]=0x00;
    dataOut[4]=0x02;
    dataOut[5]=0x00;
    dataOut[6]=0xb2;
    dataOut[7]=0x30;
    dataOut[8]=dataOut[2]^dataOut[3]^dataOut[4]^dataOut[5]^dataOut[6]^dataOut[7];
    //r=libusb_interrupt_transfer(dev_handle,LIBUSB_ENDPOINT_OUT, dataOut,9, &actual_length, 0);
    //r=libusb_bulk_transfer(dev_handle,LIBUSB_ENDPOINT_OUT,dataOut,9,&actual_length,5000);
    //此设备必须用控制传输
    r=libusb_control_transfer(dev_handle, 0x21, 0x09, 0x0300, 0x00, dataOut+1, 0x20, 1000);
    unsigned char dataRead[0x30]={0};
    r=libusb_control_transfer(dev_handle, 0xa1, 0x01, 0x0300, 0x00, dataRead, 0x20, 1000);
    if(r<0)
    {
        QMessageBox::about(this,"haha","transfer data error");
    }else
    {
        QMessageBox::about(this,"haha","transfer data success");
    }
    //release everything
    r=libusb_release_interface(dev_handle,0);
    libusb_attach_kernel_driver(dev_handle,0);
    libusb_close(dev_handle);
    libusb_exit(ctx);