视觉上位系统设计开发（halcon-winform）-5.相机

视觉的硬件输入核心相机，相机的种类很多，基本都配备可供调用的SDK，用来设置一些基本参数，以及触发图像输出。本文以海康虚拟相机为例进行说明。

海康的官方DEMO如下：

int nRet;
            // ch:创建设备列表 || en: Create device list
            System.GC.Collect();
            cbDeviceList.Items.Clear();
            nRet = MyCamera.MV_CC_EnumDevices_NET(MyCamera.MV_GIGE_DEVICE | MyCamera.MV_USB_DEVICE, ref m_pDeviceList);
            if (MyCamera.MV_OK != nRet)
            {
                MessageBox.Show("Enum Devices Fail");
                return;
            }

            // ch:在窗体列表中显示设备名 || Display the device'name on window's list
            for (int i = 0; i < m_pDeviceList.nDeviceNum; i++)
            {
                MyCamera.MV_CC_DEVICE_INFO device = (MyCamera.MV_CC_DEVICE_INFO)Marshal.PtrToStructure(m_pDeviceList.pDeviceInfo[i], typeof(MyCamera.MV_CC_DEVICE_INFO));
                if (device.nTLayerType == MyCamera.MV_GIGE_DEVICE)
                {
                    IntPtr buffer = Marshal.UnsafeAddrOfPinnedArrayElement(device.SpecialInfo.stGigEInfo, 0);
                    MyCamera.MV_GIGE_DEVICE_INFO gigeInfo = (MyCamera.MV_GIGE_DEVICE_INFO)Marshal.PtrToStructure(buffer, typeof(MyCamera.MV_GIGE_DEVICE_INFO));
                    if (gigeInfo.chUserDefinedName != "")
                    {
                        cbDeviceList.Items.Add("GigE: " + gigeInfo.chUserDefinedName + " (" + gigeInfo.chSerialNumber + ")");
                    }
                    else
                    {
                        cbDeviceList.Items.Add("GigE: " + gigeInfo.chManufacturerName + " " + gigeInfo.chModelName + " (" + gigeInfo.chSerialNumber + ")");
                    }
                }
                else if (device.nTLayerType == MyCamera.MV_USB_DEVICE)
                {
                    IntPtr buffer = Marshal.UnsafeAddrOfPinnedArrayElement(device.SpecialInfo.stUsb3VInfo, 0);
                    MyCamera.MV_USB3_DEVICE_INFO usbInfo = (MyCamera.MV_USB3_DEVICE_INFO)Marshal.PtrToStructure(buffer, typeof(MyCamera.MV_USB3_DEVICE_INFO));
                    if (usbInfo.chUserDefinedName != "")
                    {
                        cbDeviceList.Items.Add("USB: " + usbInfo.chUserDefinedName + " (" + usbInfo.chSerialNumber + ")");
                    }
                    else
                    {
                        cbDeviceList.Items.Add("USB: " + usbInfo.chManufacturerName + " " + usbInfo.chModelName + " (" + usbInfo.chSerialNumber + ")");
                    }
                }
            }

            //.ch: 选择第一项 || en: Select the first item
            if (m_pDeviceList.nDeviceNum != 0)
            {
                cbDeviceList.SelectedIndex = 0;
            }

初始化设备。

 //ch:获取选择的设备信息 | en:Get selected device information
            MyCamera.MV_CC_DEVICE_INFO device =
                (MyCamera.MV_CC_DEVICE_INFO)Marshal.PtrToStructure(m_pDeviceList.pDeviceInfo[cbDeviceList.SelectedIndex],
                                                              typeof(MyCamera.MV_CC_DEVICE_INFO));

            nRet = m_pMyCamera.MV_CC_CreateDevice_NET(ref device);
            if (MyCamera.MV_OK != nRet)
            {
                return;
            }

            // ch:打开设备 | en:Open device
            nRet = m_pMyCamera.MV_CC_OpenDevice_NET();
            if (MyCamera.MV_OK != nRet)
            {
                MessageBox.Show("Open Device Fail");
                return;
            }

            // ch:设置触发模式为off || en:set trigger mode as off
            m_pMyCamera.MV_CC_SetEnumValue_NET("AcquisitionMode", 2);
            m_pMyCamera.MV_CC_SetEnumValue_NET("TriggerMode", 0);

打开设备，并进行触发模式的设置。一般分为两种模式，连续触发，即每一帧都进行返回，触发模式则是触发一次返回一次。一般应用场景下回选择触发模式。

    if (m_bGrabbing)
            {
                m_bGrabbing = false;
                // ch:停止抓图 || en:Stop grab image
                m_pMyCamera.MV_CC_StopGrabbing_NET();

                // ch: 控件操作 || en: Control operation
                SetCtrlWhenStopGrab();
            }

            // ch:关闭设备 || en: Close device
            m_pMyCamera.MV_CC_CloseDevice_NET();

程序关闭或者相机不使用时记得关闭，否则设备将被占用，下次将无法使用，只能重置来初始化。

完整DEMO可在海康的MVS软件下找到。

相机管理的设计思路与之前通信的思路大致相同，提供相机加入的功能，封装相机的SDK提供设备列表，对相机SN进行绑定，最后根据配置进行加载。

public class CameraDeviceModel
    {
        public long Id { set; get; }
        /// <summary>
        /// 设备SN
        /// </summary>
        public string Sn { set; get; }
        public string Name { set; get; }

        public bool IsActive { set; get; } = true;
        public string CameraType { set; get; }
        /// <summary>
        /// 通信类型
        /// </summary>
        public CameraCommunicationTypeEnum CommunicationType { set; get; } = CameraCommunicationTypeEnum.Gige;
        public CameraTypeEnum Type { set; get; }

        public CameraCollectTypeEnum CameraCollectType { set; get; } = CameraCollectTypeEnum.Trigger;
        public FileFormatEnum FileFormat { set; get; } = FileFormatEnum.BMP;

        /// <summary>
        /// 曝光时间
        /// </summary>
        public decimal ExposureTime { set; get; }
        public decimal Gain { set; get; }// 增益
        /// <summary>
        /// 帧率
        /// </summary>
        public decimal FrameRate { set; get; }
    }