C# 调用继电器api usb_relay_device.dll

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace USBRelayTest
{
public class UsbRelayDeviceHelper
{
/// <summary>
/// Init the USB Relay Libary
/// </summary>
/// <returns>This function returns 0 on success and -1 on error.</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_init", CallingConvention = CallingConvention.Cdecl)]
public static extern int Init();

/// <summary>
/// Finalize the USB Relay Libary.
/// This function frees all of the static data associated with
/// USB Relay Libary. It should be called at the end of execution to avoid
/// memory leaks.
/// </summary>
/// <returns>This function returns 0 on success and -1 on error.</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_exit", CallingConvention = CallingConvention.Cdecl)]
public static extern int Exit();

/// <summary>
/// Enumerate the USB Relay Devices.
/// </summary>
/// <returns></returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_enumerate", CallingConvention = CallingConvention.Cdecl)]
public static extern IntPtr usb_relay_device_enumerate();
public static UsbRelayDeviceInfo Enumerate()
{
IntPtr x = UsbRelayDeviceHelper.usb_relay_device_enumerate();
UsbRelayDeviceInfo a = (UsbRelayDeviceInfo)Marshal.PtrToStructure(x, typeof(UsbRelayDeviceInfo));
return a;
}

/// <summary>
/// Free an enumeration Linked List
/// </summary>
/// <param name="deviceInfo"></param>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_free_enumerate", CallingConvention = CallingConvention.Cdecl)]
public static extern void FreeEnumerate(UsbRelayDeviceInfo deviceInfo);

/// <summary>
/// Open device that serial number is serialNumber
/// </summary>
/// <param name="serialNumber"></param>
/// <param name="stringLength"></param>
/// <returns>This funcation returns a valid handle to the device on success or NULL on failure.</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_open_with_serial_number", CharSet = CharSet.Ansi, CallingConvention = CallingConvention.Cdecl)]
public static extern int OpenWithSerialNumber([MarshalAs(UnmanagedType.LPStr)] string serialNumber, int stringLength);

/// <summary>
/// Open a usb relay device
/// </summary>
/// <param name="deviceInfo"></param>
/// <returns>This funcation returns a valid handle to the device on success or NULL on failure.</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_open", CallingConvention = CallingConvention.Cdecl)]
public static extern int Open(UsbRelayDeviceInfo deviceInfo);

/// <summary>
/// Close a usb relay device
/// </summary>
/// <param name="hHandle"></param>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_close", CallingConvention = CallingConvention.Cdecl)]
public static extern void Close(int hHandle);

/// <summary>
/// open a relay channel on the USB-Relay-Device
/// </summary>
/// <param name="hHandle">Which usb relay device your want to operate</param>
/// <param name="index">Which channel your want to open</param>
/// <returns>0 -- success; 1 -- error; 2 -- index is outnumber the number of the usb relay device</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_open_one_relay_channel", CallingConvention = CallingConvention.Cdecl)]
public static extern int OpenOneRelayChannel(int hHandle, int index);

/// <summary>
/// open all relay channel on the USB-Relay-Device
/// </summary>
/// <param name="hHandle">which usb relay device your want to operate</param>
/// <returns>0 -- success; 1 -- error</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_open_all_relay_channel", CallingConvention = CallingConvention.Cdecl)]
public static extern int OpenAllRelayChannels(int hHandle);

/// <summary>
/// close a relay channel on the USB-Relay-Device
/// </summary>
/// <param name="hHandle">which usb relay device your want to operate</param>
/// <param name="index">which channel your want to close</param>
/// <returns>0 -- success; 1 -- error; 2 -- index is outnumber the number of the usb relay device</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_close_one_relay_channel", CallingConvention = CallingConvention.Cdecl)]
public static extern int CloseOneRelayChannel(int hHandle, int index);

/// <summary>
/// close all relay channel on the USB-Relay-Device
/// </summary>
/// <param name="hHandle">hich usb relay device your want to operate</param>
/// <returns>0 -- success; 1 -- error</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_close_all_relay_channel", CallingConvention = CallingConvention.Cdecl)]
public static extern int CloseAllRelayChannels(int hHandle);

/// <summary>
/// status bit: High --> Low 0000 0000 0000 0000 0000 0000 0000 0000, one bit indicate a relay status.
/// the lowest bit 0 indicate relay one status, 1 -- means open status, 0 -- means closed status.
/// bit 0/1/2/3/4/5/6/7/8 indicate relay 1/2/3/4/5/6/7/8 status
/// </summary>
/// <param name="hHandle"></param>
/// <param name="status"></param>
/// <returns>0 -- success; 1 -- error</returns>
[DllImport("usb_relay_device.dll", EntryPoint = "usb_relay_device_get_status", CallingConvention = CallingConvention.Cdecl)]
public static extern int GetStatus(int hHandle, ref int status);
}

/// <summary>
/// USB relay board info structure
/// </summary>
[StructLayout(LayoutKind.Sequential, Pack = 8)]
public class UsbRelayDeviceInfo
{
[MarshalAs(UnmanagedType.LPStr)]
public string SerialNumber;

public IntPtr DevicePath { get; set; }

public UsbRelayDeviceType Type { get; set; }

public IntPtr Next { get; set; }
}

public enum UsbRelayDeviceType
{
OneChannel = 1,
TwoChannel = 2,
FourChannel = 4,
EightChannel = 8
}
}