ref种的成员声明与实现不能放在两个文件上吗？（.h&cpp）

ref类的成员声明与实现不能放在两个文件上吗？（.h&.cpp）
以下是我的代码，我将他们放在同一个文件就能编译通过。一旦分开就会出现这种错误：

这是为什么？

#pragma once
using namespace System::Collections::Generic;
using namespace System;
using namespace System::IO;
using namespace System::Text;

ref class TaskConfigFile
{
public:
	TaskConfigFile();
	TaskConfigFile(String^ str_link, Int64 file_size, short threads_sum);
	TaskConfigFile(String^ str_link, Int64 file_size);

	String^ link;//下载链接
	String^ fileName;//文件名
	String^ filePath;//文件存储路径
	Int64 fileSize;//文件总大小
	Int64 blockSize;//文件分块大小
	Int64 sumDownloadedSize;//已下载的总大小
	short threadsSum;//线程总数，默认为5

	//以字典记录各分块已下载的大小，key为分块的起始位置（字节），value为此分块已下载的大小
	Dictionary<Int64, Int64>^ blockDownloadedSize;

#ifdef DEBUG
	Debug::Listeners->Add( gcnew TextWriterTraceListener( Console::Out ) );
	Debug::AutoFlush = true;
#endif
	bool Save();//保存配置信息
	bool Load(String^ path);//加载配置信息
};

#include "stdafx.h"
#include "TaskConfigFile.h"

TaskConfigFile::TaskConfigFile():
	link(nullptr), fileName(nullptr), fileSize(0L), filePath(nullptr), blockSize(0L), sumDownloadedSize(0L), threadsSum(5)
{
	blockDownloadedSize = gcnew Dictionary<Int64, Int64>(threadsSum);
}

TaskConfigFile::TaskConfigFile(String^ str_link, Int64 file_size, short threads_sum):
	link(str_link), fileSize(file_size), threadsSum(threads_sum), sumDownloadedSize(0)
{
	blockDownloadedSize = gcnew Dictionary<Int64, Int64>(threadsSum);
}

TaskConfigFile::TaskConfigFile(String^ str_link, Int64 file_size):
	link(str_link), fileSize(file_size), threadsSum(5), sumDownloadedSize(0)
{
	blockDownloadedSize = gcnew Dictionary<Int64, Int64>(threadsSum);
}

bool TaskConfigFile::Save()
{
	String^ path = String::Concat(filePath, fileName, ".tmp");
	Stream^ writeStream = gcnew FileStream(path, FileMode::Create, FileAccess::Write);
	if(writeStream == nullptr)
	{
#ifdef DEBUG
		Diagnostics::Debug::WriteLine("文件路径错误！");
#endif
		return false;
	}

	BinaryWriter^ binaryWriter = gcnew BinaryWriter(writeStream, Encoding::ASCII);
	binaryWriter->Write(this->link);
	binaryWriter->Write(this->fileName);
	binaryWriter->Write(this->filePath);
	binaryWriter->Write(this->fileSize);
	binaryWriter->Write(this->blockSize);
	binaryWriter->Write(this->sumDownloadedSize);
	binaryWriter->Write(this->threadsSum);
	for each(KeyValuePair<Int64, Int64> pair in blockDownloadedSize)
	{
		binaryWriter->Write(pair.Key);
		binaryWriter->Write(pair.Value);
	}
	writeStream->Close();
	binaryWriter->Close();
	return true;
}

bool TaskConfigFile::Load(String^ path)
{
	Stream^ readStream = gcnew FileStream(path, FileMode::Open, FileAccess::Read);
	if(readStream == nullptr)
	{
#ifdef DEBUG
		Diagnostics::Debug::Indent();
		Diagnostics::Debug::WriteLine("error: 打开文件失败！");
		Diagnostics::Debug::WriteLine("Paht: {0}", path);
		Diagnostics::Debug::UnIndent();
#endif
		return false;
	}
	BinaryReader^ binaryReader = gcnew BinaryReader(readStream);
	try
	{
		link = binaryReader->ReadString();
		fileName = binaryReader->ReadString();
		filePath = binaryReader->ReadString();
		fileSize = binaryReader->ReadInt64();
		blockSize = binaryReader->ReadInt64();
		sumDownloadedSize = binaryReader->ReadInt64();
		threadsSum = binaryReader->ReadInt16();
		for(int i = 0; i < threadsSum; ++i)
		{
			Int64 key = binaryReader->ReadInt64();
			Int64 value = binaryReader->ReadInt64();
			blockDownloadedSize->Add(key, value);
		}
	}
	catch(EndOfStreamException^ ex)
	{
#ifdef DEBUG
		Diagnostics::Debug::Indent();
		Diagnostics::Debug::WriteLine("The end of the stream is reached."); 
		Diagnostics::Debug::WriteLine(ex->Message);
		Diagnostics::Debug::Unindent();
#endif
		readStream->Close();
		binaryReader->Close();
		return true;
	}

	return true;
	
}

------解决方案--------------------
楼主没有给TaskConfigFile.h 冠上命名空间，导致编译的时候在cpp文件中找不到.h。