求助，全注释掉，留个空函数，还是有错。。。

#include <iostream>
#include <filesystem>
#include <algorithm>
using namespace std;

bool ReduceFileName( const std::filesystem::path& path )
{
    auto make_name_name = []( const std::wstring& filename )
    {
        size_t a = filename.find( L'：' );
        if( a != std::wstring::npos )
        {
            a = filename.find_first_not_of( L"\t\n\v\f\r ", a+1 );
            size_t b = filename.find_first_of( L"(（", a );
            b = filename.find_last_not_of( L"\t\n\v\f\r ", b-1 );
            return filename.substr( a, b+1-a );
        }
        return filename;
    };

    using namespace std::filesystem;
    try
    {
        for( auto& entry : directory_iterator(path) )
        {
            if( entry.is_regular_file() ) // 只处理常规文件
            {
                auto ext = entry.path().extension().generic_wstring(); // 扩展名
                std::for_each( begin(ext), end(ext), [](auto& c){if(c>=L'A'&&c<=L'Z') c+=L'a'-L'A';} ); // 扩展名转化成小写
                if( ext == L".mp4" )
                {
                    const auto& old_name = entry.path().stem().generic_wstring();
                    const auto& new_name = make_name_name( old_name );
                    if( old_name != new_name )
                    {
                        wcout << old_name << L" -> " << new_name;

                        auto new_path = entry.path().parent_path()/(new_name+L".mp4");
                        if( exists(new_path) ) // 新文件名已经存在
                        {
                            wcout << L" --- [failed] 文件已存在";
                        }
                        else
                        {
                            std::error_code ec;
                            rename( entry, new_path, ec );
                            if( ec )
                                cout << " --- [failed] " << ec.message();
                        }

                        wcout << L'\n';
                    }
                }
            }
        }
    }
    catch( const std::exception& e )
    {
        cout << "[failed] " << e.what() << '\n';
        return false;
    }
    return true;
}

int main( void )
{
    setlocale( LC_CTYPE, "" ); // 改了这一句

    ReduceFileName( u8R"(C:\Users\Administrator\Desktop\[WPF]JJDown\Download\)" ); // 使用 Unicode 可避免GBK认字不全
}

以下是引用追梦人zmrghy在2022-5-30 13:48:20的发言：

VS2022。C＋＋中如何创建CLR窗体。。。