LINQ搜索查詢

Question

下面的函數返回文件表中的所有行，即使如果應用，其中過濾器，

public IList<File> SearchFiles(int? FileID, int? type, int? Status) 
     { 

      var files = from fil in _context.Files 
          select fil; 

      if (FileID != null) 
      { 
       files.Where(x => x.FileID == FileID); 
      } 

      if (type != null) 
      { 
       files.Where(x => x.FileTypeID == type); 
      } 

      if (Status != null) 
      { 
       files.Where(x => x.FileStatusID == Status); 
      } 

      return files.ToList<File>(); 
     } 

任何錯誤我在做什麼嗎？

在此先感謝！

Answer 1

您需要分配在哪裏回的IQueryable ....（即：文件= files.where（....

public IList<File> SearchFiles(int? FileID, int? type, int? Status) 
    { 

     var files = from fil in _context.Files 
         select fil; 

     if (FileID != null) 
     { 
      files = files.Where(x => x.FileID == FileID); 
     } 

     if (type != null) 
     { 
      files = files.Where(x => x.FileTypeID == type); 
     } 

     if (Status != null) 
     { 
      files = files.Where(x => x.FileStatusID == Status); 
     } 

     return files.ToList<File>(); 
    }