前面我们已经完成了控制传输部分的开发，现在继续进行端点相关的传输部分开发。先实现接口和端点信息的解析，以便用户选择某个接口下的某个端点进行收发。
参考libusb_get_active_config_descriptor()获取描述符信息，然后进行解析，注意使用完需要调用libusb_free_config_descriptor释放资源。
使用变量s_interface_num记录接口数，一个接口下的不同alt接口算不同的接口。
定义结构体 usbddev_interface_info_st记录接口和端点信息。
定义全局数组 s_interface_info记录接口和端点信息，最大可记录MAX_INTERFACE 个接口
每个接口最大MAX_ENDPOINTS 个端点。
Usbdev.c提供数据结构如下:
int s_interface_num = 0; /* 打开的设备的接口数 *//*** 记录接口信息结构体*/typedef struct{int interfacenumber;int alternateSetting;int numendpoints;struct libusb_endpoint_descriptor endpoints[MAX_ENDPOINTS];} usbddev_interface_info_st;usbddev_interface_info_st s_interface_info[MAX_INTERFACE];
Usbdev.c提供获取接口和端点信息接口实现如下
int usbdev_update_interface_endpoint_list(void){struct libusb_config_descriptor * config;struct libusb_interface * interface;struct libusb_interface_descriptor* altsetting;struct libusb_endpoint_descriptor * endpoint;if(s_opened_dev != NULL){memset(&s_interface_info,0,sizeof(s_interface_info));if(0 == libusb_get_active_config_descriptor(s_opened_dev,&config)){s_interface_num = 0;if(config != NULL){interface = config->interface;for(int i=0; i< config->bNumInterfaces; i++){for(int j=0; j{altsetting = interface[i].altsetting;s_interface_info[s_interface_num].interfacenumber = altsetting[j].bInterfaceNumber;s_interface_info[s_interface_num].alternateSetting = altsetting[j].bAlternateSetting;s_interface_info[s_interface_num].numendpoints = altsetting[j].bNumEndpoints;for(int k=0; k{endpoint = altsetting[j].endpoint;s_interface_info[s_interface_num].endpoints[k] = endpoint[k];}s_interface_num++;}}libusb_free_config_descriptor(config);}}else{return -2;}}else{return -1;}return 0;}
Usbdev.c提供以下接口获取接口数和接口的id
int usbdev_get_interface_num(void){return s_interface_num;}int usbdev_get_in_interface_id(int itf_index, int* interface, int* altsetting){if(itf_index >= s_interface_num){return -1;}*interface = s_interface_info[itf_index].interfacenumber;*altsetting = s_interface_info[itf_index].alternateSetting;return 0;}
Usbdev.c提供以下信息获取指定接口的端点数和端点信息
int usbdev_get_endpoint_num(int itf_index){if(itf_index >= s_interface_num){return -1;}return s_interface_info[itf_index].numendpoints;}int usbdev_get_endpoint_info(int itf_index, int ep_index, int* address, int* type, int* mps){struct libusb_endpoint_descriptor* endpoint;if(itf_index >= s_interface_num){return -1;}if(ep_index >= s_interface_info[itf_index].numendpoints){return -1;}endpoint = s_interface_info[itf_index].endpoints;*address = endpoint[ep_index].bEndpointAddress;*type = endpoint[ep_index].bmAttributes;*mps = endpoint[ep_index].wMaxPacketSize;return 0;}
Usbdev.h中声明接口
int usbdev_update_interface_endpoint_list(void);int usbdev_get_interface_num(void);int usbdev_get_in_interface_id(int itf_index, int* interface, int* altsetting);int usbdev_get_endpoint_num(int itf_index);int usbdev_get_endpoint_info(int itf_index, int ep_index, int* address, int* type, int* mps);
打开设备时,接口下拉框中显示接口信息，关闭设备时清除接口显示
打开按钮的处理函数下添加
void MainWindow::on_pushButton_clicked(){int index = ui->comboBox->currentIndex();if(index < 0){return;}if(0 == usbdev_get_openstatus()){printf("to open dev %d\r\n",index);if(0 == usbdev_open(index)){ui->pushButton->setText("关闭");/* 这里更新显示接口下拉框的内容 */ui->comboBox_3->clear();ui->comboBox_4->clear();ui->comboBox_2->clear();ui->comboBox_5->clear();usbdev_update_interface_endpoint_list(); /* 更新接口和端点信息 */int int_num = usbdev_get_interface_num();int itf_id;int alt_id;for(int i = 0; i{if(0 == usbdev_get_in_interface_id(i,&itf_id,&alt_id)){QString itfstr= QString::number(i)+":"+QString::number(itf_id)+":"+QString::number(alt_id);ui->comboBox_3->addItems(QStringList(itfstr));ui->comboBox_4->addItems(QStringList(itfstr));}}}}else{usbdev_close();ui->pushButton->setText("打开");/* 这里清除显示接口下拉框的内容 */ui->comboBox_3->clear();ui->comboBox_4->clear();ui->comboBox_2->clear();ui->comboBox_5->clear();}}
右键点击ui界面的下拉框->转为槽
添加activated事件处理函数
void MainWindow::on_comboBox_3_activated(int index){}
实现如下
void MainWindow::on_comboBox_3_activated(int index){int epnum = usbdev_get_endpoint_num(index);ui->comboBox_2->clear();for(int i=0; i< epnum; i++){int address;int type;int mps;if(0 == usbdev_get_endpoint_info(index, i, &address, &type, &mps)){QString epstr= QString::number(i)+":"+QString("%1").arg(address & 0xFF, 2, 16, QLatin1Char('0'))+":"+QString("%1").arg(mps & 0xFF, 2, 16, QLatin1Char('0'))+":";switch(type & 0x03){case 0:epstr = epstr + "CTRL";break;case 1:epstr = epstr + "ISOC";break;case 2:epstr = epstr + "BULK";break;case 3:epstr = epstr + "INT";break;}ui->comboBox_2->addItems(QStringList(epstr));}}}
同样的接收区添加
void MainWindow::on_comboBox_4_activated(int index){}
实现如下
void MainWindow::on_comboBox_4_activated(int index){int epnum = usbdev_get_endpoint_num(index);ui->comboBox_5->clear();for(int i=0; i< epnum; i++){int address;int type;int mps;if(0 == usbdev_get_endpoint_info(index, i, &address, &type, &mps)){QString epstr= QString::number(i)+":"+QString("%1").arg(address & 0xFF, 2, 16, QLatin1Char('0'))+":"+QString("%1").arg(mps & 0xFF, 2, 16, QLatin1Char('0'))+":";switch(type & 0x03){case 0:epstr = epstr + "CTRL";break;case 1:epstr = epstr + "ISOC";break;case 2:epstr = epstr + "BULK";break;case 3:epstr = epstr + "INT";break;}ui->comboBox_5->addItems(QStringList(epstr));}}}
打开设备接口显示
关闭设备接口清除显示
显示信息和UsbTreeView看到的美剧信息一致，0:0接口下面3个端点
以上完成了接口和端点信息的解析，后面就可以选择端点，进行对应的传输了。
