介紹
評論本來是要放到標籤裡面去講的，但是因為上一章東西有點多了，我就沒放進去，這一章單獨拿出來，內容不多大家自己寫寫就可以，也算是對前面講解的一個小練習吧。
相關注釋我也加在程式碼上面了，大家看看程式碼都可以理解。
評論倉儲介面和實現
public interface ICommentRepository : IBasicRepository<Comment, Guid>
{
/// <summary>
/// 根據文章Id 獲取評論
/// </summary>
/// <param name="postId"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
Task<List<Comment>> GetListOfPostAsync(Guid postId, CancellationToken cancellationToken = default);
/// <summary>
/// 根據文章Id 獲取評論數量
/// </summary>
/// <param name="postId"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
Task<int> GetCommentCountOfPostAsync(Guid postId, CancellationToken cancellationToken = default);
/// <summary>
/// 根據評論Id 下面的子獲取評論
/// </summary>
/// <param name="id"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
Task<List<Comment>> GetRepliesOfComment(Guid id, CancellationToken cancellationToken = default);
Task DeleteOfPost(Guid id, CancellationToken cancellationToken = default);
}
public class EfCoreCommentRepository:EfCoreRepository<CoreDbContext, Comment, Guid>,ICommentRepository
{
public EfCoreCommentRepository(IDbContextProvider<CoreDbContext> dbContextProvider) : base(dbContextProvider)
{
}
public async Task<List<Comment>> GetListOfPostAsync(Guid postId, CancellationToken cancellationToken = default)
{
return await (await GetDbSetAsync())
.Where(a => a.PostId == postId)
.OrderBy(a => a.CreationTime)
.ToListAsync(GetCancellationToken(cancellationToken));
}
public async Task<int> GetCommentCountOfPostAsync(Guid postId, CancellationToken cancellationToken = default)
{
return await (await GetDbSetAsync())
.CountAsync(a => a.PostId == postId, GetCancellationToken(cancellationToken));
}
public async Task<List<Comment>> GetRepliesOfComment(Guid id, CancellationToken cancellationToken = default)
{
return await (await GetDbSetAsync())
.Where(a => a.RepliedCommentId == id).ToListAsync(GetCancellationToken(cancellationToken));
}
public async Task DeleteOfPost(Guid id, CancellationToken cancellationToken = default)
{
var recordsToDelete = await (await GetDbSetAsync()).Where(pt => pt.PostId == id).ToListAsync(GetCancellationToken(cancellationToken));
(await GetDbSetAsync()).RemoveRange(recordsToDelete);
}
}
評論介面和Dto
public interface ICommentAppService : IApplicationService
{
Task<List<CommentWithRepliesDto>> GetHierarchicalListOfPostAsync(Guid postId);
Task<CommentWithDetailsDto> CreateAsync(CreateCommentDto input);
Task<CommentWithDetailsDto> UpdateAsync(Guid id, UpdateCommentDto input);
Task DeleteAsync(Guid id);
}
public class CommentWithRepliesDto
{
public CommentWithDetailsDto Comment { get; set; }
public List<CommentWithDetailsDto> Replies { get; set; } = new List<CommentWithDetailsDto>();
}
public class CommentWithDetailsDto : FullAuditedEntityDto<Guid>
{
public Guid? RepliedCommentId { get; set; }
public string Text { get; set; }
public BlogUserDto Writer { get; set; }
}
public class CreateCommentDto
{
public Guid? RepliedCommentId { get; set; }
public Guid PostId { get; set; }
[Required]
public string Text { get; set; }
}
public class UpdateCommentDto
{
[Required]
public string Text { get; set; }
}
介面實現
public class CommentAppService : CoreAppService, ICommentAppService
{
private IUserLookupService<IdentityUser> UserLookupService { get; }
private readonly ICommentRepository _commentRepository;
private readonly IGuidGenerator _guidGenerator;
public CommentAppService(ICommentRepository commentRepository, IGuidGenerator guidGenerator, IUserLookupService<IdentityUser> userLookupService)
{
_commentRepository = commentRepository;
_guidGenerator = guidGenerator;
UserLookupService = userLookupService;
}
public async Task<List<CommentWithRepliesDto>> GetHierarchicalListOfPostAsync(Guid postId)
{
// 獲取評論資料
var comments = await GetListOfPostAsync(postId);
#region 對評論的作者進行賦值
var userDictionary = new Dictionary<Guid, BlogUserDto>();
foreach (var commentDto in comments)
{
if (commentDto.CreatorId.HasValue)
{
var creatorUser = await UserLookupService.FindByIdAsync(commentDto.CreatorId.Value);
if (creatorUser != null && !userDictionary.ContainsKey(creatorUser.Id))
{
userDictionary.Add(creatorUser.Id, ObjectMapper.Map<IdentityUser, BlogUserDto>(creatorUser));
}
}
}
foreach (var commentDto in comments)
{
if (commentDto.CreatorId.HasValue && userDictionary.ContainsKey((Guid)commentDto.CreatorId))
{
commentDto.Writer = userDictionary[(Guid)commentDto.CreatorId];
}
}
#endregion
var hierarchicalComments = new List<CommentWithRepliesDto>();
#region 包裝評論資料格式
// 評論包裝成2級（ps:前面的查詢根據時間排序，這裡不要擔心子集在父級前面）
foreach (var commentDto in comments)
{
var parent = hierarchicalComments.Find(c => c.Comment.Id == commentDto.RepliedCommentId);
if (parent != null)
{
parent.Replies.Add(commentDto);
}
else
{
hierarchicalComments.Add(new CommentWithRepliesDto() { Comment = commentDto });
}
}
hierarchicalComments = hierarchicalComments.OrderByDescending(c => c.Comment.CreationTime).ToList();
#endregion
return hierarchicalComments;
}
public async Task<CommentWithDetailsDto> CreateAsync(CreateCommentDto input)
{
// 也可以使用這種方式(這裡只是介紹用法) GuidGenerator.Create()
var comment = new Comment(_guidGenerator.Create(), input.PostId, input.RepliedCommentId, input.Text);
comment = await _commentRepository.InsertAsync(comment);
await CurrentUnitOfWork.SaveChangesAsync();
return ObjectMapper.Map<Comment, CommentWithDetailsDto>(comment);
}
public async Task<CommentWithDetailsDto> UpdateAsync(Guid id, UpdateCommentDto input)
{
var comment = await _commentRepository.GetAsync(id);
comment.SetText(input.Text);
comment = await _commentRepository.UpdateAsync(comment);
return ObjectMapper.Map<Comment, CommentWithDetailsDto>(comment);
}
public async Task DeleteAsync(Guid id)
{
await _commentRepository.DeleteAsync(id);
var replies = await _commentRepository.GetRepliesOfComment(id);
foreach (var reply in replies)
{
await _commentRepository.DeleteAsync(reply.Id);
}
}
private async Task<List<CommentWithDetailsDto>> GetListOfPostAsync(Guid postId)
{
var comments = await _commentRepository.GetListOfPostAsync(postId);
return new List<CommentWithDetailsDto>(
ObjectMapper.Map<List<Comment>, List<CommentWithDetailsDto>>(comments));
}
}
CreateMap<Comment, CommentWithDetailsDto>().Ignore(x => x.Writer);
結語
說明：
- 1.整個評論的實現非常簡單，我們只是實現了一個2層的巢狀。
- 2.下一章我們講授權和策略大家應該會比較喜歡，加油
聯絡作者：加群：867095512 @MrChuJiu
