对象到字节— System.InvalidCastException

Question

writing a C# function for one of your RPA robots, I get a 'System.InvalidCastException'. Compiling the same code in VS 2015, no Exception occures.

The code:

try
{
    byte[] IColByte = new byte[4]{
                          (byte)ICol.Rows[0]["B"], 
                          (byte)ICol.Rows[0]["G"], 
                          (byte)ICol.Rows[0]["R"], 
                          (byte)ICol.Rows[0]["A"]};
}
catch(System.Exception e)
{
    throw new System.Exception("ERROR: Unable to create color byte array!" +
        System.Environment.NewLine + e.Message);
}   

ICol is from type System.Data.DataTable defined like this:

public static System.Data.DataTable GenerateColor(byte B, byte G, byte R, byte A)
{
    System.Data.DataTable dt = new System.Data.DataTable();
    dt.Columns.Add(new System.Data.DataColumn("B", typeof(byte)));
    dt.Columns.Add(new System.Data.DataColumn("G", typeof(byte)));
    dt.Columns.Add(new System.Data.DataColumn("R", typeof(byte)));
    dt.Columns.Add(new System.Data.DataColumn("A", typeof(byte)));

    dt.Rows.Add(dt.NewRow());
    dt.Rows[0]["B"] = B;
    dt.Rows[0]["G"] = G;
    dt.Rows[0]["R"] = R;
    dt.Rows[0]["A"] = A;

    return dt;
}

I don't understand, whats wrong with this code? Even, if the warning level is very low...

Answer 1

There is nothing wrong with it, and the program below runs with no errors, so the definition of ICol must be the culprit.

using System;
using System.Data;

public class Program
{
    public static void Main()
    {
        var ICol = GenerateColor(2, 3, 4, 5);
        byte[] IColByte = new byte[4]{
            (byte)ICol.Rows[0]["B"], 
            (byte)ICol.Rows[0]["G"], 
            (byte)ICol.Rows[0]["R"], 
            (byte)ICol.Rows[0]["A"]};
        Console.WriteLine(String.Join(", ", IColByte));  // Writes "2, 3, 4, 5"
    }

    public static System.Data.DataTable GenerateColor(byte B, byte G, byte R, byte A)
    {
        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.Add(new System.Data.DataColumn("B", typeof(byte)));
        dt.Columns.Add(new System.Data.DataColumn("G", typeof(byte)));
        dt.Columns.Add(new System.Data.DataColumn("R", typeof(byte)));
        dt.Columns.Add(new System.Data.DataColumn("A", typeof(byte)));

        dt.Rows.Add(dt.NewRow());
        dt.Rows[0]["B"] = B;
        dt.Rows[0]["G"] = G;
        dt.Rows[0]["R"] = R;
        dt.Rows[0]["A"] = A;

        return dt;
    }
}

https://dotnetfiddle.net/uGUKfP