c# - 系统.DllNotFoundException : Unable to load DLL 'i2c.so'

Question

正在运行接近传感器程序，但不幸的是，由于导入 DLL 时出错，我无法编译该程序。

这是错误:

DLL 来自 i2c.cs 文件:

private static class I2CNativeLib
{
    [DllImport("i2c.so", EntryPoint = "Get", SetLastError = true)]
    public static extern int Get(string i2Cbusid, string deviceaddress, string dataaddress);

    [DllImport("i2c.so", EntryPoint = "Set", SetLastError = true)]
    public static extern int Set(string i2Cbusid, string deviceaddress, string dataaddress, string datavalue, int force);
}

作为引用，这里是完整的 i2c.cs 文件，下面是主要文件:

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

namespace RPi.I2C.Net
{
    internal abstract class i2c
    {
        internal static Dictionary<string, int> Constants { get; set; }

        protected static int Set16(string i2Cbusid, string deviceaddress, string dataaddress, string datavalue, int force)
        {
            var value = (UInt16)Convert.ToInt16(datavalue, 16);

            var add1 = (UInt16)Convert.ToInt16(dataaddress, 16);
            var add2 = ++add1;

            var msb = GetAsHexString(value >> 8);
            var lsb = GetAsHexString(value & 0xFF);
            Console.WriteLine("16-bit: Writing 16-bit Value: {0} as 2 8-bit values {1} and {2}", GetAsHexString(value), msb, lsb);

            Console.WriteLine("16-bit: Writing {0} to address {1}", msb, GetAsHexString(add1));
            var data = I2CNativeLib.Set(i2Cbusid, deviceaddress, GetAsHexString(add1), msb, force); //set msb byte/8 bits
            Console.WriteLine("16-bit: Response to msb: {0}", data);


            Console.WriteLine("16-bit: Writing {0} to address {1}", lsb, GetAsHexString(add2));
            data |= I2CNativeLib.Set(i2Cbusid, deviceaddress, GetAsHexString(add2), lsb, force); //set lsb byte/8 bits
            Console.WriteLine("16-bit: Response to msb |= lsb: {0}", data);
            return data;

        }

        protected static byte Set8(string i2Cbusid, string deviceaddress, string dataaddress, string datavalue, int force)
        {
            Console.WriteLine("8-bit: Writing {0} to address {1}", datavalue, dataaddress);
            //8-bit
            return (byte)I2CNativeLib.Set(i2Cbusid, deviceaddress, dataaddress, datavalue, force);
        }
        protected static byte Get(string i2Cbusid, string deviceaddress, string dataaddress)
        {
            return (byte)I2CNativeLib.Get(i2Cbusid, deviceaddress, dataaddress);
        }

        internal string Busid = string.Empty;
        internal bool DoWork = false;

        protected i2c()
        {
            Constants = new Dictionary<string, int>();
        }

        internal static int GetConstantAsByte(string key)
        {
            int value;
            Constants.TryGetValue(key, out value);
            return value;
        }
        internal static string GetConstantAsString(string key)
        {
            int value;
            Constants.TryGetValue(key, out value);
            return "0x" + value.ToString("X").PadLeft(2, '0');
        }
        internal static string GetAsHexString(uint value)
        {
            return "0x" + value.ToString("X").PadLeft(2, '0');
        }
        internal static string GetAsHexString(int value)
        {
            return "0x" + value.ToString("X").PadLeft(2, '0');
        }
        internal byte GetValue8(string deviceAddress, string dataAddress)
        {
            var result = Get(
                Busid,
                GetConstantAsString(deviceAddress),
                GetConstantAsString(dataAddress)
            );
            return result;
        }
        internal UInt16 GetValue16(string deviceAddress, string dataAddress)
        {
            var result = (UInt16)(Get(Busid, GetConstantAsString(deviceAddress), GetConstantAsString(dataAddress)) << 8);
            result |= Get(Busid, GetConstantAsString(deviceAddress), GetConstantAsString(dataAddress));

            return result;
        }
        internal abstract void Start();
        internal virtual void Stop()
        {
            DoWork = false;
        }
        private static class I2CNativeLib
        {
            [DllImport("i2c.so", EntryPoint = "Get", SetLastError = true)]
            public static extern int Get(string i2Cbusid, string deviceaddress, string dataaddress);

            [DllImport("i2c.so", EntryPoint = "Set", SetLastError = true)]
            public static extern int Set(string i2Cbusid, string deviceaddress, string dataaddress, string datavalue, int force);
        }
    }
    }

这是主要文件:

using System;

namespace i2c
{
  class Program
  {
    static void Main(string[] argv)
    {
        try
        {
            Console.WriteLine("Starting Communication with VCNL4000");
            var vcnl4000 = new VCNL4000("1", 100);
            vcnl4000.ProximityReading += sensor_ProximityReading;
            var productId = vcnl4000.ProductID;
            OutputValue(productId, "Product ID");
            vcnl4000.Start();

            //Console.WriteLine("Starting Communication with ADS1115");
            //var ads1115 = new ADS1115("1");
            //ads1115.Message += ads1115_Message;
            //ads1115.SingleEndedConversionReading += ads1115_ConversionReading;
            //ads1115.Start();                

            Console.WriteLine("Press Esc key to stop");
            do
            {
                while (!Console.KeyAvailable)
                {
                    // Do something
                }
            } while (Console.ReadKey(true).Key != ConsoleKey.Escape);

            //ads1115.Stop();
            vcnl4000.Stop();


        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }

    static void ads1115_Message(object sender, ConverterMessageEventArgs e)
    {
        OutputValue(e.Message, "Convertor");
    }
    private static void OutputValue(string response, string message)
    {
        Console.WriteLine(message + " Response: {0}", response);
    }
    private static void ads1115_ConversionReading(object sender, SingleEndedConversionEventArgs e)
    {
        var _sender = (ADS1115)sender;
        OutputValue(e.Data, "Conversion Reading");
    }
    static void sensor_ProximityReading(object sender, ProximtyEventArgs e)
    {
        var sensor = (VCNL4000)sender;
        OutputValue(e.Proximity, "Proximity Reading");
        OutputValue(e.RawValue, "Proximity Raw Value");
    }
    private static void OutputValue(int response, string message) 
    {
        Console.WriteLine(message  + " Response: {0} (0x{1})", response, response.ToString("X"));
    }
    private static void OutputValue(decimal response, string message)
    {
        Console.WriteLine(message + " Response: {0}", response);
    }
    private static void OutputValue(float response, string message)
    {
        Console.WriteLine(message + " Response: {0}", response);
    }
  }
}

Answer 1

我认为代码示例是我在 GitHub 上编写和共享的代码，所以也许我可以在这里提供帮助。我最近添加了包含以下信息的 ReadMe.txt 文件:

The i2c.so file can be placed in the same folder as the mono assembly (bin folder) or copied to the /usr/lib/ folder to be available to all mono assemblies. In some cases you may see DLL File Not Found exceptions, but placing in /usr/lib should resolve that.

So copy the i2c.so file to /usr/lib/ directory

linux command:

cp i2c.so /usr/lib/

To rebuild the i2c.so file, from shell, "CD" to the location of the files, and run the "make" command.

linux command:

make

"make" will run the build defined in the makefile definition.

Code borrowed from i2ctools, v3.1.0, see Credits.txt and Licence.txt

重要的部分是将 i2c.so 文件复制到/usr/lib/目录。

如果您没有 i2c.so，或者您需要一个更新的版本，文件底部是关于如何构建 i2c.so 的线索。

可能值得指出的是，代码最初打算使用 Mono 在 Raspberry Pi 上运行。

https://github.com/silentbobbert/pi_sensors