Return 从 C# COM 库到 VBA 的数组

Question

我花了很多时间试图找到解决方案，但我似乎无法让它发挥作用。情况如下：

我正在设置一个供 vba 宏使用的 c# com 库。有问题的 c# 库方法将两个数组作为参数， returns 一个大小和类型与第一个参数相同的数组。这是 c# 代码（接口和实现）：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Windows.Forms;

namespace Aufbereiten.Base.Controller
{
    [Guid("A341A58B-96CA-42B8-8256-B8AC16586176")]
    public interface IExposer
    {
        [DispId(1)]
        void Connect(String macroName, String inputFileName, String functionType);
        [DispId(2)]
        Boolean Run();
        [DispId(3)]
        object[] StringCleaner(object lineOut, object headerOut);
    }

    [Guid("C66FF152-60E2-4AF3-9D65-655C224A241E")]
    [Serializable(), ClassInterface(ClassInterfaceType.None), ComVisible(true)]
    public class Library : IExposer
    {
        #region Fields
        private MainController _mc;
        #endregion

        #region Properties
        public MainController MC
        {
            get { return _mc; }
            set { _mc = value; }
        }
        #endregion

        #region Methods
        public void Connect(String macroName, String fileName, String functionType)
        {
            MC = new MainController(macroName, fileName, functionType);
        }

        public Boolean Run()
        {
            return MC.Run();
        }

        /// <summary>
        /// Cleans input string of unwanted characters
        /// </summary>
        /// <param name="lineOut">String Array</param>
        /// <param name="headerOut">Integer Array</param>
        /// <returns>String array</returns>
        public object[] StringCleaner(object lineOut, object headerOut)
        {
            // Convert input objects to List and convert return List to string array directly
            return MC.Generic.StringCleaner(ComObjectToStringList(lineOut), ComObjectToIntList(headerOut)).ToArray<string>();
        }

        /// <susgbomary>
        /// Converts a com object into a string list
        /// </summary>
        /// <param name="comObj">object</param>
        /// <returns>String list</returns>
        private List<string> ComObjectToStringList(object comObj)
        {
            List<string> result = new List<string>();

            // Convert COM object (VBA array) to string list
            Type comObjType = comObj.GetType();

            object[] args = new object[1];
            int numEntries = (int)comObjType.InvokeMember("Length", BindingFlags.GetProperty, null, comObj, null);
            for (int i = 0; i < numEntries; i++)
            {
                args[0] = i;
                string currentEntry = (string)comObjType.InvokeMember("GetValue", BindingFlags.InvokeMethod, null, comObj, args);
                if (currentEntry == null)
                {
                    result.Add("");
                }
                else
                {
                    result.Add(currentEntry);
                }
            }

            return result;
        }

        /// <summary>
        /// Converts a com object into an int list
        /// </summary>
        /// <param name="comObj">object</param>
        /// <returns>Int32 list</returns>
        private List<int> ComObjectToIntList(object comObj)
        {
            List<int> result = new List<int>();

            // Convert COM object (VBA array) to int list
            Type comObjType = comObj.GetType();

            object[] args = new object[1];
            int numEntries = (int)comObjType.InvokeMember("Length", BindingFlags.GetProperty, null, comObj, null);
            for (int i = 0; i < numEntries; i++)
            {
                args[0] = i;
                result.Add((int)comObjType.InvokeMember("GetValue", BindingFlags.InvokeMethod, null, comObj, args));
            }

            return result;
        }
        #endregion
    }
}

Generic.StringCleaner 方法将执行清除不需要字符的参数数组 "lineOut" 的实际工作。以下是调用库方法的 VBA 代码的摘录：

Dim arrLineOut() As Variant
Dim dicInToOut As New Scripting.Dictionary

...

Dim lib As New Aufbereiten.library
lib.Connect ThisWorkbook.Name, "_Library_Test_custFile.xlsx", "CustImport"
arrLineOut = lib.StringCleaner(arrLineOut, dicInToOut.Items)

c#中的所有操作运行完美无缺，除了返回结果，清理数组。

当我运行宏时，我得到一个

runtime error 80131533: A mismatch has occurred between the runtime type of the array and the sub type recorded in the metadata.

谁能告诉我我做错了什么？

Answer 1

根据@Meehow 的建议我已经调整了

public object[] StringCleaner(object lineOut, object headerOut)

至

public string[] StringCleaner(object lineOut, object headerOut)

和

return MC.Generic.StringCleaner(ComObjectToStringList(lineOut), ComObjectToIntList(headerOut)).ToArray<string>();

至

return MC.Generic.StringCleaner(ComObjectToStringList(lineOut), ComObjectToIntList(headerOut)).ToArray();

进行这些更改后，我能够将 c# 库中的 return 值分配给 VBA 中新声明的变体数组：

Dim tmp As Variant
tmp = lib.StringCleaner(arrLineOut, dicInToOut.Items)

Return 从 C# COM 库到 VBA 的数组

Return Array from C# COM Library to VBA

c#

com

vba

interop