如何在c＃中将字符串列表转换为字符串

问题描述：

public List<Movie> mType(List<string> fType)
       {
           List<Movie> fMovie = new List<Movie>();
           foreach(Movie movie in ListOfMovies)
           {
               if (fType = movie.Type)//this is where the error is
               {
                   fMovie.Add(movie);
               }//end of if
           }//end of foreach
           return fMovie;
       }

无法将类型'string'隐式转换为'System.Collections.Generic.List< string>'

这是我得到的错误，任何帮助将不胜感激

Cannot implicitly convert type 'string' to 'System.Collections.Generic.List<string>'

This is the error i am getting, any help will be appreciated

答

我假设您要检查该电影类型是列表中的一个字符串...

使用列表< T> .Contains（T） [ ^ ]方法...

I assume you want to check that movie type is one of the strings in the list...
Use List<T>.Contains(T)[^] method...

if (fType.Contains(movie.Type))
{
  // ...
}

如果 fType 不是很短，那么可以使用 HashSet< string> 来优化：>

If the fType is not very short, then this can be optimized using a HashSet<string> :

public List<Movie> mType(List<string> fType)
{
  List<Movie> fMovie = new List<Movie>();
  HashSet<string> typesMap = new HashSet<string>(fType);
  foreach(Movie movie in ListOfMovies)
  {
    if (typesMap.Contains(movie.Type))
    {
      fMovie.Add(movie);
    }//end of if
  }//end of foreach
  return fMovie;
}

使用Linq这将是：

And using Linq this would be:

public List<Movie> mType(List<string> fType)
{
  HashSet<string> typesMap = new HashSet<string>(fType);
  return (from movie in ListOfMovies where typesMap.Contains(movie.Type) select movie).ToList();
}

如何在c＃中将字符串列表转换为字符串

相关推荐