linq-to-sql - 我如何将参数传递给linq查询

Question

我想将参数传递给 linq 查询...

public IEnumerable GetPhotos()
{
    PhotoDBDataContext db = new PhotoDBDataContext();
    var query = from p in db.Photos
                orderby p.PhotoId descending
                select new { p.Album, p.AlbumId, p.Description, p.Photographer,
                             p.PhotographerId, p.PhotoId, p.Tags, p.Thumbnail,
                             p.Url };
    return query;
}

在上面的例子中使用了“orderby p.PhotoId descending”，我想用参数代替p.PhotoId

有没有可能...

Answer 1

public IQueryable<Photo> GetPhotos(PhotoDBDataContext db, string orderBy)
{
    var query = from p in db.Photos select p;
    switch (orderBy) {
        case "PhotoId":
            return query.OrderBy(p => p.PhotoId);
        case "AlbumId":
            return query.OrderBy(p => p.AlbumId);
        default:
            // Error handling.
    } 
}

请注意，您不应返回匿名类型的对象。