c# - 从 Fairbanks SCB-9000 USB 秤读取重量

Question

我正在尝试创建一个可以调用的可执行文件，并从 Fairbanks SCB-9000 USB 秤传回重量。我找到了一些适用于不同模型比例的代码，但它对我来说不太适用。我特别对以下方法有疑问。它给我一个错误:“无法将类型‘System.Collections.Generic.IEnumerable’隐式转换为‘HidLibrary.HidDevice[]’。”我已经尝试了几种转换方式，但我无法让它发挥作用。这里有什么建议，或者有人曾经为这个特定的规模编写过任何代码吗？

谢谢，

罗布

这里是有问题的方法:

    public HidDevice[] GetDevices()
    {
        HidDevice[] hidDeviceList;

        // Fairbanks Scale
        hidDeviceList = HidDevices.Enumerate(0x0B67, 0x555E);

        if (hidDeviceList.Length > 0)

            return hidDeviceList;

    }

抱歉应该补充说我正在使用 Mike Obrien 的 HidLibrary 来自这里:http://nuget.org/packages/hidlibrary

更新完整代码...

这是我正在使用的代码...

program.cs

using System;
using System.Threading;
using HidLibrary;
using Scale;

namespace ScaleReader
{
    class Program
    {
        public static void Main(string[] args)
        {
            decimal? weight;
            bool? isStable;

            USBScale s = new USBScale();
            s.Connect();

            if (s.IsConnected)
            {
                s.GetWeight(out weight, out isStable);
                s.DebugScaleData();
                Console.WriteLine("Weight: {0:0.00} LBS", weight);
            }
            else
            {
                Console.WriteLine("No Scale Connected.");
            }

            s.Disconnect();
            Thread.Sleep(500);
        }
    }
}

Scale.cs

using HidLibrary;
using System.Threading;
using System;
using System.Collections.Generic;
using System.Text;

namespace Scale
{
    class USBScale
    {
        public bool IsConnected
        {
            get
            {
                return scale == null ? false : scale.IsConnected;
            }
        }
        public decimal ScaleStatus
        {
            get
            {
                return inData.Data[1];
            }
        }
        public decimal ScaleWeightUnits
        {
            get
            {
                return inData.Data[2];
            }
        }
        private HidDevice scale;
        private HidDeviceData inData;

public HidDevice[] GetDevices() 
{ 
    return HidDevices.Enumerate(0x0B67, 0x555E).Cast<HidDevice>().ToArray(); 
} 

        public bool Connect()
        {
            // Find a Scale
            HidDevice[] deviceList = GetDevices();

            if (deviceList.Length > 0)

                return Connect(deviceList[0]);

            else

                return false;
        }
        public bool Connect(HidDevice device)
        {
            scale = device;
            int waitTries = 0;
            scale.OpenDevice();

            // sometimes the scale is not ready immedietly after
            // Open() so wait till its ready
            while (!scale.IsConnected && waitTries < 10)
            {
                Thread.Sleep(50);
                waitTries++;
            }
            return scale.IsConnected;
        }
        public void Disconnect()
        {
            if (scale.IsConnected)
            {
                scale.CloseDevice();
                scale.Dispose();
            }
        }
        public void DebugScaleData()
        {
            for (int i = 0; i < inData.Data.Length; ++i)
            {
                Console.WriteLine("Byte {0}: {1}", i, inData.Data[i]);
            }
        }
        public void GetWeight(out decimal? weight, out bool? isStable)
        {
            weight = null;
            isStable = false;

            if (scale.IsConnected)
            {
                inData = scale.Read(250);
                // Byte 0 == Report ID?
                // Byte 1 == Scale Status (1 == Fault, 2 == Stable @ 0, 3 == In Motion, 4 == Stable, 5 == Under 0, 6 == Over Weight, 7 == Requires Calibration, 8 == Requires Re-Zeroing)
                // Byte 2 == Weight Unit
                // Byte 3 == Data Scaling (decimal placement)
                // Byte 4 == Weight LSB
                // Byte 5 == Weight MSB

                // FIXME: dividing by 100 probably wont work with
                // every scale, need to figure out what to do with
                // Byte 3
                weight = (Convert.ToDecimal(inData.Data[4]) +
                    Convert.ToDecimal(inData.Data[5]) * 256) / 100;

                switch (Convert.ToInt16(inData.Data[2]))
                {
                    case 3:  // Kilos
                        weight = weight * (decimal?)2.2;
                        break;
                    case 11: // Ounces
                        weight = weight * (decimal?)0.625;
                        break;
                    case 12: // Pounds
                        // already in pounds, do nothing
                        break;
                }
                isStable = inData.Data[1] == 0x4;
            }
        }
    }
}

Answer 1

你所拥有的不会编译，因为你并不总是返回一些东西。根据错误消息，这就是您真正需要的。我找不到任何关于 HidDevice 或 HidDevices 的引用，所以我不能说这将绝对确定地工作。

public HidDevice[] GetDevices()
{
    return HidDevices.Enumerate(0x0B67, 0x555E).Cast<HidDevice>().ToArray();
}

你必须添加这一行才能编译:

using System.Linq;

---

作为旁注，获取 ReSharper。