libusb-1.0-成功调用libusb_bulk_transfer()后，数据将流向何处?

本文介绍了libusb-1.0-成功调用libusb_bulk_transfer()后，数据将流向何处?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我运行了从此处的教程获得的以下代码示例: http://www.dreamincode.net/forums/topic/148707-introduction-to-using-libusb-10/

I ran the following code sample obtained from a tutorial here: http://www.dreamincode.net/forums/topic/148707-introduction-to-using-libusb-10/

我将其运行在通过USB连接到运行Mac OS X Mountain Lion的MacBook Pro的运行Android 4的平板电脑上.
输出包含编写成功！"所以我假设libusb_bulk_transfer()正常工作.我的问题是将4个字节的数据传输到哪里?我可以将其保存到Android平板电脑上的文件中吗?

I ran it against a tablet running Android 4 attached via USB to a MacBook Pro running Mac OS X Mountain Lion.
The output contained "Writing Successful!" so I assume libusb_bulk_transfer() worked correctly. My question is where did the 4 bytes of data got transferred to? Can I save it to a file on the Android tablet?

感谢您的帮助！

#include <iostream>
#include <libusb.h>

using namespace std;

int main() {
    libusb_device **devs; //pointer to pointer of device, used to retrieve a list of devices
    libusb_device_handle *dev_handle; //a device handle
    libusb_context *ctx = NULL; //a libusb session
    int r; //for return values
    ssize_t cnt; //holding number of devices in list
    r = libusb_init(&ctx); //initialize the library for the session we just declared
    if(r < 0) {
        cout<<"Init Error "<<r<<endl; //there was an error
        return 1;
    }
    libusb_set_debug(ctx, 3); //set verbosity level to 3, as suggested in the documentation

    cnt = libusb_get_device_list(ctx, &devs); //get the list of devices
    if(cnt < 0) {
        cout<<"Get Device Error"<<endl; //there was an error
        return 1;
    }
    cout<<cnt<<" Devices in list."<<endl;

    dev_handle = libusb_open_device_with_vid_pid(ctx, 5118, 7424); //these are vendorID and productID I found for my usb device
    if(dev_handle == NULL)
        cout<<"Cannot open device"<<endl;
    else
        cout<<"Device Opened"<<endl;
    libusb_free_device_list(devs, 1); //free the list, unref the devices in it

    unsigned char *data = new unsigned char[4]; //data to write
    data[0]='a';data[1]='b';data[2]='c';data[3]='d'; //some dummy values

    int actual; //used to find out how many bytes were written
    if(libusb_kernel_driver_active(dev_handle, 0) == 1) { //find out if kernel driver is attached
        cout<<"Kernel Driver Active"<<endl;
        if(libusb_detach_kernel_driver(dev_handle, 0) == 0) //detach it
            cout<<"Kernel Driver Detached!"<<endl;
    }
    r = libusb_claim_interface(dev_handle, 0); //claim interface 0 (the first) of device (mine had jsut 1)
    if(r < 0) {
        cout<<"Cannot Claim Interface"<<endl;
        return 1;
    }
    cout<<"Claimed Interface"<<endl;

    cout<<"Data->"<<data<<"<-"<<endl; //just to see the data we want to write : abcd
    cout<<"Writing Data..."<<endl;
    r = libusb_bulk_transfer(dev_handle, (2 | LIBUSB_ENDPOINT_OUT), data, 4, &actual, 0); //my device's out endpoint was 2, found with trial- the device had 2 endpoints: 2 and 129
    if(r == 0 && actual == 4) //we wrote the 4 bytes successfully
        cout<<"Writing Successful!"<<endl;
    else
        cout<<"Write Error"<<endl;

    r = libusb_release_interface(dev_handle, 0); //release the claimed interface
    if(r!=0) {
        cout<<"Cannot Release Interface"<<endl;
        return 1;
    }
    cout<<"Released Interface"<<endl;

    libusb_close(dev_handle); //close the device we opened
    libusb_exit(ctx); //needs to be called to end the

    delete[] data; //delete the allocated memory for data
    return 0;
}

成功调用libusb

libusb-1.0-成功调用libusb_bulk_transfer()后，数据将流向何处?

问题描述

推荐答案