篇(18)-Asp.Net Core入门实战-文章管理之文章内容管理(下拉框二级结构递归)
篇(18)-Asp.Net Core入门实战-文章管理之文章内容管理(下拉框二级结构递归实现)
文章管理是CMS系统的核心表之一，存储文章内容，特点就是字段端，属性多，比如是否标识为热点、推荐等属性，是否发布，类别，SEO关键字等。我们本章讲解文章内容的增删改查。
（1）.文章Sql表结构设计
CREATE TABLE [dbo].[Article]( [Id] [int] IDENTITY(1,1) NOT NULL, [CategoryId] [int] NOT NULL, [Title] [varchar](128) NOT NULL, [ImageUrl] [varchar](128) NULL, [Content] [text] NULL, [ViewCount] [int] NOT NULL, [Sort] [int] NOT NULL, [Author] [varchar](64) NULL, [Source] [varchar](128) NULL, [SeoTitle] [varchar](128) NULL, [SeoKeyword] [varchar](256) NULL, [SeoDescription] [varchar](512) NULL, [AddManagerId] [int] NOT NULL, [AddTime] [datetime] NOT NULL, [ModifyManagerId] [int] NULL, [ModifyTime] [datetime] NULL, [IsTop] [bit] NOT NULL, [IsSlide] [bit] NOT NULL, [IsRed] [bit] NOT NULL, [IsPublish] [bit] NOT NULL, [IsDeleted] [bit] NOT NULL, CONSTRAINT [PK_ARTICLE] PRIMARY KEY NONCLUSTERED ( [Id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO SET ANSI_PADDING OFF GO ALTER TABLE [dbo].[Article] ADD DEFAULT (getdate()) FOR [AddTime] GO ALTER TABLE [dbo].[Article] ADD DEFAULT ((0)) FOR [IsTop] GO ALTER TABLE [dbo].[Article] ADD DEFAULT ((0)) FOR [IsSlide] GO ALTER TABLE [dbo].[Article] ADD DEFAULT ((0)) FOR [IsRed] GO ALTER TABLE [dbo].[Article] ADD DEFAULT ((0)) FOR [IsPublish] GO ALTER TABLE [dbo].[Article] ADD DEFAULT ((0)) FOR [IsDeleted] GO ALTER TABLE [dbo].[Article] WITH CHECK ADD CONSTRAINT [FK_ARTICLE_RELATIONS_ARTICLEC] FOREIGN KEY([CategoryId]) REFERENCES [dbo].[ArticleCategory] ([Id]) GO ALTER TABLE [dbo].[Article] CHECK CONSTRAINT [FK_ARTICLE_RELATIONS_ARTICLEC] GO
那么对应的Article Model代码如下：
public class Article { /// <summary> /// 主键 /// </summary> [Key] public Int32 Id { get; set; } /// <summary> /// 分类ID /// </summary> [Required] public Int32 CategoryId { get; set; } /// <summary> /// 文章标题 /// </summary> [Required] public String Title { get; set; } /// <summary> /// 图片地址 /// </summary> public String ImageUrl { get; set; } /// <summary> /// 文章内容 /// </summary> public String Content { get; set; } /// <summary> /// 浏览次数 /// </summary> [Required] public Int32 ViewCount { get; set; } /// <summary> /// 排序 /// </summary> [Required] public Int32 Sort { get; set; } /// <summary> /// 作者 /// </summary> public String Author { get; set; } /// <summary> /// 来源 /// </summary> public String Source { get; set; } /// <summary> /// SEO标题 /// </summary> public String SeoTitle { get; set; } /// <summary> /// SEO关键字 /// </summary> public String SeoKeyword { get; set; } /// <summary> /// SEO描述 /// </summary> public String SeoDescription { get; set; } /// <summary> /// 添加人ID /// </summary> [Required] public Int32 AddManagerId { get; set; } /// <summary> /// 添加时间 /// </summary> [Required] public DateTime AddTime { get; set; } /// <summary> /// 修改人ID /// </summary> public Int32? ModifyManagerId { get; set; } /// <summary> /// 修改时间 /// </summary> public DateTime? ModifyTime { get; set; } /// <summary> /// 是否置顶 /// </summary> public Boolean IsTop { get; set; } /// <summary> /// 是否轮播显示 /// </summary> public Boolean IsSlide { get; set; } /// <summary> /// 是否热门 /// </summary> public Boolean IsRed { get; set; } /// <summary> /// 是否发布 /// </summary> public Boolean IsPublish { get; set; } /// <summary> /// 是否删除 /// </summary> [Required] public Boolean IsDeleted { get; set; } }
（2）.视图Create代码
（2.1）视图代码
考虑到要同时上传图片，注意form表单的额 enctype类型；
@{ ViewData["Title"] = "新建文章"; } @model Article <form action="/Article/Create" method="post" enctype="multipart/form-data"> @Html.AntiForgeryToken() <div> <label asp-for="Title">标题</label> <div> <input type="text" asp-for="Title" name="Title" placeholder="请输入标题"> </div> </div> <div> <label asp-for="CategoryId">文章类型</label> <div> @Html.DropDownList("ddl_CategoryId", ViewBag.database as IEnumerable<SelectListItem>) </div> </div> <div> <label>设置</label> <div> @*@Html.CheckBox("IsTop") 置顶 @Html.CheckBox("IsRed") 热点 @Html.CheckBox("IsSlide") 幻灯*@ <input type="checkbox" name="IsTop" asp-for="IsTop" />置顶 <input type="checkbox" name="IsRed" asp-for="IsRed"/>热点 <input type="checkbox" name="IsSlide" asp-for="IsSlide" />幻灯 </div> </div> <div> <label asp-for="ImageUrl">文章首页图</label> <div> <input type="file" asp-for="ImageUrl" name="ImageUrl"/> </div> </div> <div> <label asp-for="Content">内容</label> <div> <textarea placeholder="内容" asp-for="Content" name="Content" cols="30" rows="10"></textarea> </div> </div> <div> <label asp-for="Sort">排序</label> <div> <input type="text" placeholder="排序" asp-for="Sort" name="Sort" /> </div> </div> <div> <label asp-for="ViewCount">点击量</label> <div> <input type="text" placeholder="点击量" asp-for="ViewCount" name="ViewCount" /> </div> </div> <div> <label asp-for="IsPublish">是否发布</label> <div> <select asp-for="IsPublish" name="IsPublish" class="IsPublish"> <option value="False">否</option> <option value="True" selected>是</option> </select> </div> </div> <div> <label asp-for="Author">作者</label> <div> <input type="text" asp-for="Author" name="Author" placeholder="作者名"> </div> </div> <div> <label asp-for="Source">来源</label> <div> <input type="text" asp-for="Source" name="Source" placeholder="文章来源"> </div> </div> <div> <label asp-for="SeoTitle">SEO标题</label> <div> <input type="text" asp-for="SeoTitle" name="SeoTitle" placeholder="SEO标题"> </div> </div> <div> <label asp-for="SeoKeyword">SEO关键词</label> <div> <input type="text" asp-for="SeoKeyword" name="SeoKeyword" placeholder="SEO关键词"> </div> </div> <div> <label asp-for="SeoDescription">SEO摘要描述</label> <div> <input type="text" asp-for="SeoDescription" name="SeoDescription" placeholder="SEO摘要描述"> </div> </div> <div> <div> <button type="submit">确定</button> <button type="reset">重置</button> </div> </div> </form>
（2.2）视图中的下拉框的实现方式（递归和循环嵌套）
我想在添加文章时，实现一个具有二级层次结构的下拉框，如上图所示。所以，在对下拉框进行数据绑定时，就要费点功夫，上个章节讲文章类别管理时，的表结构就一个，分类都存在一张表中，所以要进行递归的获取子菜单或者通过循环嵌套来实现。
递归的主要核心函数为：
/// <summary> /// 递归函数，实现获取子菜单 /// </summary> /// <param name="lists">递归前的列表</param> /// <param name="newlists">递归后的新列表</param> /// <param name="parentId">父Id</param> /// <returns></returns> public static List<CategorySelectItemListView> GetChildCategory(List<CategorySelectItemListView> lists, List<CategorySelectItemListView> newlists, int parentId) { newlists = new List<CategorySelectItemListView>(); List<CategorySelectItemListView> tempList = lists.Where(c => c.ParentId == parentId).ToList(); for (int i = 0; i < tempList.Count; i++) { CategorySelectItemListView category = new CategorySelectItemListView(); category.Id = tempList[i].Id; category.ParentId = tempList[i].ParentId; category.Title = tempList[i].Title; category.Children = GetChildCategory(lists, newlists, category.Id); newlists.Add(category); } return newlists; } /// <summary> /// 循环嵌套，实现获取子菜单 /// </summary> /// <param name="lists">循环遍历前的列表</param> /// <returns></returns> public static List<CategorySelectItemListView> GetChildCategory(List<CategorySelectItemListView> lists) { List<CategorySelectItemListView> categorylist = new List<CategorySelectItemListView>(); for (int i = 0; i < lists.Count; i++) { if (0 == lists[i].ParentId) categorylist.Add(lists[i]); for (int j = 0; j < lists.Count; j++) { if (lists[j].ParentId == lists[i].Id) lists[i].Children.Add(lists[j]); } } return categorylist; }
然后在Create和Edit的Action中去绑定对应的下拉菜单即可。
注意：List<CategorySelectItemListView> 集合的CategorySelectItemListView，这个是新建的ViewModel对象，用来专门绑定下拉菜单使用，其代码如下：
public class CategorySelectItemListView { public int Id { get; set; } public string Title { get; set; } public int ParentId { get; set; } public List<CategorySelectItemListView> Children { get; set; } public CategorySelectItemListView() { Children = new List<CategorySelectItemListView>(); } public CategorySelectItemListView(int id,string title,int parentid) { this.Id = id; this.Title = title; this.ParentId = parentid; Children = new List<CategorySelectItemListView>(); } public CategorySelectItemListView(int id, string title, CategorySelectItemListView parent) { this.Id = id; this.Title = title; this.ParentId = parent.Id; Children = new List<CategorySelectItemListView>(); }
（3）.视图Edit代码，注解部分的代码可以参考，我尝试用过，也可以达到目的，演练代码最好是用多种方式实现，查看其区别，这样掌握的牢固一些。
@{ ViewData["Title"] = "编辑文章"; } @model Article @section Scripts{ <script type="text/javascript" src="~/js/jquery-3.6.1.min.js"></script> <script type="text/javascript"> $(document).ready(function () { $.ajax({ type: "GET", url: "/ArticleCategory/GetCategory", data: "{}", success: function (data) { console.log(data); var s = '<option value="0">请选择</option>'; for (var i = 0; i < data.length; i++) { s += '<option value="' + data[i].Title + '"+>' + data[i].Id + '</option>'; } $("#ArticleCategory").html(s); } }); }); </script> } <form action="/Article/Edit" method="post" enctype="multipart/form-data"> @Html.AntiForgeryToken() <div> <label asp-for="Title">标题</label> <div> <input type="text" asp-for="Title" name="Title" placeholder="请输入标题"> <input type="hidden" asp-for="Id" /> </div> </div> <div> <label asp-for="CategoryId">文章类型</label> <div> @Html.DropDownList("ddl_CategoryId", ViewBag.database as IEnumerable<SelectListItem>) </div> </div> <div> <label>设置</label> <div> @*@Html.CheckBox("IsTop", Model.IsTop,new { value = Model.IsTop}) 置顶 @Html.CheckBox("IsRed", Model.IsRed, new { value = Model.IsRed }) 热点 @Html.CheckBox("IsSlide", Model.IsSlide, new { value = Model.IsSlide }) 幻灯*@ <input asp-for="IsTop" />置顶 <input asp-for="IsRed" />热点 <input asp-for="IsSlide" />幻灯 @*<input type="checkbox" name="IsTop" @(Html.Raw(@Model.IsTop ? "checked=\"checked\"" : "")) asp-for="IsTop" />置顶 <input type="checkbox" name="IsRed" @(Html.Raw(@Model.IsRed ? "checked=\"checked\"" : "")) asp-for="IsRed" />热点 <input type="checkbox" name="IsSlide" @(Html.Raw(@Model.IsSlide ? "checked=\"checked\"" : "")) asp-for="IsSlide" />幻灯*@ @*<input type="checkbox" name="IsTop" asp-for="IsTop" />置顶 <input type="checkbox" name="IsRed" asp-for="IsRed"/>热点 <input type="checkbox" name="IsSlide" asp-for="IsSlide"/>幻灯*@ </div> </div> <div> <label asp-for="ImageUrl">文章首页图</label> <div> <input type="file" asp-for="ImageUrl" name="ImageUrl" /> <label asp-for="ImageUrl">@Model.ImageUrl</label> </div> </div> <div> <label asp-for="Content">内容</label> <div> <textarea placeholder="内容" asp-for="Content" name="Content" cols="30" rows="10"></textarea> </div> </div> <div> <label asp-for="Sort">排序</label> <div> <input type="text" placeholder="排序" asp-for="Sort" name="Sort" /> </div> </div> <div> <label asp-for="ViewCount">点击量</label> <div> <input type="text" placeholder="点击量" asp-for="ViewCount" name="ViewCount" /> </div> </div> <div> <label asp-for="IsPublish">是否发布</label> <div> <select asp-for="IsPublish" name="IsPublish" class="IsPublish"> <option value="False">否</option> <option value="True" selected>是</option> </select> </div> </div> <div> <label asp-for="Author">作者</label> <div> <input type="text" asp-for="Author" name="Author" placeholder="作者名"> </div> </div> <div> <label asp-for="Source">来源</label> <div> <input type="text" asp-for="Source" name="Source" placeholder="文章来源"> </div> </div> <div> <label asp-for="SeoTitle">SEO标题</label> <div> <input type="text" asp-for="SeoTitle" name="SeoTitle" placeholder="SEO标题"> </div> </div> <div> <label asp-for="SeoKeyword">SEO关键词</label> <div> <input type="text" asp-for="SeoKeyword" name="SeoKeyword" placeholder="SEO关键词"> </div> </div> <div> <label asp-for="SeoDescription">SEO摘要描述</label> <div> <input type="text" asp-for="SeoDescription" name="SeoDescription" placeholder="SEO摘要描述"> </div> </div> <div> <div> <button type="submit">确定</button> <button type="reset">重置</button> </div> </div> </form>
（4）.视图Index列表的代码
针对列表的显示，又专门编写了ArticeView的这个ViewModel。
public class ArticleView { public int Id { get; set; } public int CategoryId { get; set; } public string CategoryName { get; set; } public string Title { get; set; } public int ViewCount { get; set; } public int Sort { get; set; } public string Author { get; set; } public string Source { get; set; } public int AddManagerId { get; set; } public DateTime AddTime { get; set; } }
@using Humanizer; @using RjWebCms.Db; @using RjWebCms.Models.Articles; @model PaginatedList<ArticleView> @{ ViewData["Title"] = "文章列表"; } @section Scripts{ <script src="~/js/jquery-2.1.0.min.js"></script> <script type="text/javascript"> function DelAll() { var ids = document.getElementsByName("#chk_ids"); var arrIds = ""; var n = 0; for (var i = 0; i < ids.length; i++) { if (ids[i].checked == true) { arrIds += ids[i].value + ","; n++; } } if (n == 0) { alert("请选择要删除的信息"); return; } arrIds = arrids.substr(0, arrIds.length - 1); // if (confirm("确定要全部删除选择信息吗")) { $.ajax({ type: "post", url: "/Article/DeleteAll", data: { ids: arrIds }, success: function (data, state) { alert('删除成功!'); window.location.href = ""; }, error: function (data, state) { alert('删除失败'); } }); } } </script> } <div class="panel panel-default todo-panel"> <div class="panel-heading">@ViewData["Title"]</div> @Html.AntiForgeryToken() <form asp-action="Index" method="get"> <table> <tr><td><a asp-controller="Article" asp-action="Create">添加</a></td></tr> <tr> <td>查询关键词:<input type="text" name="SearchString" value="@ViewData["CurrentFilter"]" /></td> <td><input type="submit" value="查询" /></td> <td><a asp-action="Index">Back</a></td> <td><a asp-action="DeleteAll">批量删除</a></td> </tr> </table> </form> <table class="table table-hover"> <thead> <tr> <td>✔</td> <td><a asp-action="Index" asp-route-sortOrder="@ViewData["NameSortParm"]" asp-route-currentFilter="@ViewData["CurrentFilter"]">标题</a></td> <td>类别</td> <td><a asp-action="Index" asp-route-sortOrder="@ViewData["DateSortParm"]" asp-route-currentFilter="@ViewData["CurrentFilter"]">添加时间</a></td> <td>作者</td> <td>操作</td> </tr> @foreach (var item in Model) { <tr> <td><input type="checkbox" class="done-checkbox" name="chk_ids" value="@item.Id"></td> <td>@item.Title</td> <td>@item.CategoryName</td> <td>@item.AddTime</td> <td>@item.Author</td> <td> <a asp-action="Details" asp-route-id="@item.Id">Details</a> <a asp-action="Edit" asp-route-id="@item.Id">Edit</a> <a asp-action="Delete" asp-route-id="@item.Id">Delete</a> </td> </tr> } </thead> </table> @{ var prevDisabled = !Model.HasPreviousPage ? "disabled" : ""; var nextDisabled = !Model.HasNextPage ? "disabled" : ""; ; } <a asp-action="Index" asp-route-sortOrder="@ViewData["CurrentSort"]" asp-route-pageNumber="@(Model.PageIndex - 1)" asp-route-currentFilter="@ViewData["CurrentFilter"]" class="btn btn-default @prevDisabled"> 上一页 </a> <a asp-action="Index" asp-route-sortOrder="@ViewData["CurrentSort"]" asp-route-pageNumber="@(Model.PageIndex + 1)" asp-route-currentFilter="@ViewData["CurrentFilter"]" class="btn btn-default @nextDisabled"> 下一页 </a> <div class="panel-footer add-item-form"> <!--TODO: Add item form --> </div> </div>
（5）.Controller部分的全部代码，注意看代码注释
public class ArticleController : Controller { private readonly IHostEnvironment _hostEnvironment; private readonly IArticleService _articleService; private readonly IArticleCategoryService _articleCategoryService; private readonly AppDbContext _appDbContext; public ArticleController(IArticleService articleService, IArticleCategoryService articleCategoryService,AppDbContext appDbContext,IHostEnvironment hostEnvironment) { _hostEnvironment = hostEnvironment; _appDbContext = appDbContext; _articleService = articleService; _articleCategoryService = articleCategoryService; } public async Task<IActionResult> Index(string sortOrder, string currentFilter, string searchString, int? pageNumber) { ViewData["CurrentSort"] = sortOrder; ViewData["NameSortParm"] = String.IsNullOrEmpty(sortOrder) ? "name_desc" : ""; ViewData["DateSortParm"] = sortOrder == "Date" ? "date_desc" : "Date"; if (searchString != null) { pageNumber = 1; } else { searchString = currentFilter; } ViewData["CurrentFilter"] = searchString; var article = from s in _appDbContext.Article join p in _appDbContext.ArticleCategory on s.CategoryId equals p.Id select new ArticleView { Id = s.Id, CategoryId = s.CategoryId, CategoryName = p.Title, Title = s.Title, Sort = s.Sort, AddManagerId = s.AddManagerId, AddTime = s.AddTime, Author = s.Author, Source = s.Source, ViewCount = s.ViewCount, }; if (!string.IsNullOrEmpty(searchString)) { article = article.Where(s => s.Title.Contains(searchString)); } switch (sortOrder) { case "name_desc": article = article.OrderByDescending(s => s.Title) ; break; case "Date": article = article.OrderBy(s => s.AddTime); break; case "date_desc": article = article.OrderByDescending(s => s.AddTime); break; default: article = article.OrderBy(s => s.Title); break; } int pageSize = 4; return View(await PaginatedList<ArticleView>.CreateAsync(article.AsNoTracking(), pageNumber ?? 1, pageSize)); } [HttpGet] public async Task<IActionResult> CreateAsync() { #region 绑定类别下拉框 var categories = await _articleCategoryService.GetArticleCategory();//列出文章类别字典 var categoryItems = new List<SelectListItem>() { new SelectListItem(){ Value="0",Text="全部",Selected=true} }; //全部列出并转成DropDownList对象 List<CategorySelectItemListView> list = new List<CategorySelectItemListView>(); foreach (var category in categories) { list.Add(new CategorySelectItemListView { Id=category.Id, Title = category.Title, ParentId = category.ParentId }); } #region 循环嵌套调用 //List<CategorySelectItemListView> list1 = GetChildCategory(list); //foreach (var li in list1) //{ // categoryItems.Add(new SelectListItem { Value = li.Id.ToString(), Text = li.Title }); // if (li.Children.Count > 0) // { // foreach(var t in li.Children) // categoryItems.Add(new SelectListItem { Value = t.Id.ToString(),Text= "|-" + t.Title }); // } //} #endregion #region 递归调用 List<CategorySelectItemListView> list1 = GetChildCategory(list, new List<CategorySelectItemListView>(), 0); foreach (var li in list1) { categoryItems.Add(new SelectListItem { Value = li.Id.ToString(), Text = li.Title }); if (li.Children.Count > 0) { foreach (var t in li.Children) categoryItems.Add(new SelectListItem { Value = t.Id.ToString(), Text = " |-" + t.Title }); } } #endregion ViewBag.database = categoryItems; #endregion return View(); } [HttpPost] [ValidateAntiForgeryToken] public async Task<IActionResult> CreateAsync(Article article,[FromForm]IFormCollection fromData) { //去掉对字段IsSystem的验证,IsSystem在数据库是bool类型,而前端是0和1，ModelState的验证总是报false，所以去掉对其验证 //ModelState.Remove("IsSystem");//在View端已经解决了了bool类型，那么此行代码可以不用 #region 下拉菜单 string strCategoryId = Request.Form["ddl_CategoryId"]; if (!string.IsNullOrEmpty(strCategoryId)) article.CategoryId = int.Parse(strCategoryId); else article.CategoryId = 0; #endregion #region 复选框 article.IsTop = fromData["IsTop"] != "false";//使用FormCollection时，可以这样 article.IsRed = fromData["IsRed"] != "false"; article.IsSlide = fromData["IsSlide"] != "false"; //也可以这样取值，但要注意View内的写法 //if (!string.IsNullOrEmpty(fromData["IsTop"])) // article.IsTop = true; //else // article.IsTop = false; #endregion #region 上传文件 IFormFileCollection files = fromData.Files; foreach(var formFile in files) { //var fileName = ContentDispositionHeaderValue.Parse(file.ContentDisposition).FileName.Trim('"'); string webContentPath = _hostEnvironment.ContentRootPath; var fileExt = formFile.FileName.Substring(formFile.FileName.LastIndexOf('.'));//文件扩展名 var fileNew = DateTime.Now.ToString("yyyyMMddHHmmss") + fileExt; //给文件重新命名 //string upLoadPath = webContentPath + $@"\{fileName}"; string upLoadPath = webContentPath + $@"\UpFiles"; var fileUrl = upLoadPath + $@"\{fileNew}"; if (formFile.Length > 0) { using (var stream = new FileStream(fileUrl,FileMode.Create)) { await formFile.CopyToAsync(stream); } } article.ImageUrl = "../UpFiles/" + fileNew; } #endregion if (ModelState.IsValid) { var successful = await _articleService.AddArticleAysnc(article); if (successful) return RedirectToAction("Index"); else return BadRequest("失败"); } return View(article); } [HttpGet] public async Task<IActionResult> Edit(int id) { if (string.IsNullOrEmpty(id.ToString())) return NotFound(); var article = await _articleService.FindArticleAsync(id); if (article == null) return NotFound(); #region 绑定角色下拉框 var categories = await _articleCategoryService.GetArticleCategory();//列出文章类别字典 var categoryItems = new List<SelectListItem>() { new SelectListItem(){ Value="0",Text="全部",Selected=true} }; //全部列出并转成DropDownList对象 List<CategorySelectItemListView> list = new List<CategorySelectItemListView>(); foreach (var category in categories) { list.Add(new CategorySelectItemListView { Id = category.Id, Title = category.Title, ParentId = category.ParentId }); } #region 递归调用 List<CategorySelectItemListView> list1 = GetChildCategory(list, new List<CategorySelectItemListView>(), 0); foreach (var li in list1) { categoryItems.Add(new SelectListItem { Value = li.Id.ToString(), Text = li.Title }); if (li.Children.Count > 0) { foreach (var t in li.Children) categoryItems.Add(new SelectListItem { Value = t.Id.ToString(), Text = " |-" + t.Title }); } } #endregion #region 遍历并选中 foreach (SelectListItem item in categoryItems) { if (item.Value == article.CategoryId.ToString()) item.Selected = true; } #endregion ViewBag.database = categoryItems; #endregion return View(article); } [HttpPost] [ValidateAntiForgeryToken] public async Task<IActionResult> Edit(int id, [FromForm]Article article) { if (id != article.Id) { return NotFound(); } #region 下拉菜单 string strCategoryId = Request.Form["ddl_CategoryId"]; if (!string.IsNullOrEmpty(strCategoryId)) article.CategoryId = int.Parse(strCategoryId); else article.CategoryId = 0; #endregion #region 复选框 if (Request.Form["IsTop"].Contains("true")) article.IsTop = true; else article.IsTop = false; if (Request.Form["IsRed"].Contains("true")) article.IsRed = true; else article.IsRed = false; if (Request.Form["IsSlide"].Contains("true")) article.IsSlide = true; else article.IsSlide = false; #endregion //ModelState.Remove("IsTop"); //ModelState.Remove("IsRed"); //ModelState.Remove("IsSlide"); if (ModelState.IsValid) { try { var result = await _articleService.UpdateArticleAsync(id, article); //跳转 if (result) return RedirectToAction("Index"); else return BadRequest("编辑失败"); } catch (Exception ex) { return BadRequest("编辑失败"); } } else { return BadRequest("数据输入有误！"); } } /// <summary> /// 递归函数，实现获取子菜单 /// </summary> /// <param name="lists">递归前的列表</param> /// <param name="newlists">递归后的新列表</param> /// <param name="parentId">父Id</param> /// <returns></returns> public static List<CategorySelectItemListView> GetChildCategory(List<CategorySelectItemListView> lists, List<CategorySelectItemListView> newlists, int parentId) { newlists = new List<CategorySelectItemListView>(); List<CategorySelectItemListView> tempList = lists.Where(c => c.ParentId == parentId).ToList(); for (int i = 0; i < tempList.Count; i++) { CategorySelectItemListView category = new CategorySelectItemListView(); category.Id = tempList[i].Id; category.ParentId = tempList[i].ParentId; category.Title = tempList[i].Title; category.Children = GetChildCategory(lists, newlists, category.Id); newlists.Add(category); } return newlists; } /// <summary> /// 循环嵌套，实现获取子菜单 /// </summary> /// <param name="lists">循环遍历前的列表</param> /// <returns></returns> public static List<CategorySelectItemListView> GetChildCategory(List<CategorySelectItemListView> lists) { List<CategorySelectItemListView> categorylist = new List<CategorySelectItemListView>(); for (int i = 0; i < lists.Count; i++) { if (0 == lists[i].ParentId) categorylist.Add(lists[i]); for (int j = 0; j < lists.Count; j++) { if (lists[j].ParentId == lists[i].Id) lists[i].Children.Add(lists[j]); } } return categorylist; } }
（6）.Service应用层代码
public class ArticleService : IArticleService { private readonly AppDbContext _appDbContext; public ArticleService(AppDbContext appDbContext) { _appDbContext = appDbContext; } /// <summary> /// 添加文章 /// </summary> /// <param name="article"></param> /// <returns></returns> public async Task<bool> AddArticleAysnc(Article article) { article.IsDeleted = false; article.AddManagerId = 1;//用户id article.AddTime = DateTime.Now; article.IsPublish = true; await _appDbContext.Article.AddAsync(article); var result = await _appDbContext.SaveChangesAsync(); return result == 1; } /// <summary> /// 删除文章 /// </summary> /// <param name="Id"></param> /// <returns></returns> public async Task<bool> DeleteArticleAsync(int Id) { var article = await _appDbContext.Article.FirstOrDefaultAsync(x => x.Id == Id); if (article != null) { _appDbContext.Article.Remove(article); } var result = await _appDbContext.SaveChangesAsync(); return result == 1; //注意(result==1 如果等式成立，则返回true，说明删除成功) } /// <summary> /// 按Id查询文章 /// </summary> /// <param name="Id"></param> /// <returns></returns> public async Task<Article> FindArticleAsync(int Id) { var item = await _appDbContext.Article.Where(x => x.Id == Id).FirstOrDefaultAsync(); return item; } /// <summary> /// 按标题查询文章 /// </summary> /// <param name="title"></param> /// <returns></returns> public async Task<Article[]> GetArtcleByTitle(string title) { var items = await _appDbContext.Article.Where(x => x.Title.Contains(title)).ToArrayAsync(); return items; } /// <summary> /// 查询文章 /// </summary> /// <returns></returns> public async Task<Article[]> GetArticles() { var items = await _appDbContext.Article.Where(x => x.IsDeleted==false).ToArrayAsync(); return items; } /// <summary> /// 更新文章 /// </summary> /// <param name="id"></param> /// <param name="article"></param> /// <returns></returns> public async Task<bool> UpdateArticleAsync(int id, Article article) { var oldArticle = await FindArticleAsync(id); //找出旧对象 //将新值赋到旧对象上 oldArticle.Title = article.Title; oldArticle.CategoryId = article.CategoryId; oldArticle.SeoDescription = article.SeoDescription; oldArticle.SeoTitle = article.SeoTitle; oldArticle.SeoKeyword = article.SeoKeyword; oldArticle.Content = article.Content; oldArticle.Sort = article.Sort; oldArticle.Source = article.Source; oldArticle.IsSlide = article.IsSlide; oldArticle.IsPublish = article.IsPublish; oldArticle.IsRed = article.IsRed; oldArticle.IsTop = article.IsTop; oldArticle.ViewCount = article.ViewCount; oldArticle.Author = article.Author; oldArticle.ImageUrl = article.ImageUrl; oldArticle.ModifyManagerId = 11;// oldArticle.ModifyTime = DateTime.Parse(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")); //对旧对象执行更新 _appDbContext.Entry(oldArticle).State = EntityState.Modified; var result = await _appDbContext.SaveChangesAsync(); return result == 1; } }
再谈CheckBox的使用
1.在View视图页增加的代码格式如果为：
<input type="checkbox" name="IsTop" asp-for="IsTop" />置顶
或者是这样：
<input asp-for="IsTop" />置顶
那么在生成的html代码中，都会自动成id，name，type=“checkbox” value的属性。
2.在Controller中进行取值时的代码为：
if (Request.Form["IsTop"].Contains("true"))
article.IsTop = true;
else
article.IsTop = false;
跟踪时发现，View中Checkbox选中是，会产生true和false两个值，如图跟踪变量发现:
如此，取值时，就用了Contains功能，因为View中CheckBox没选中，这只有一个false值；
3.在View视图页增加代码的格式如果为：
<input type="checkbox" name="IsTop" @(Html.Raw(@Model.IsTop ? "checked=\"checked\"" : "")) asp-for="IsTop" />置顶
4.在Controller中进行取值时的代码为：
if (!string.IsNullOrEmpty(Request.Form["IsTop"]))
article.IsTop = true;
else
article.IsTop = false;
跟踪时发现，View中的CheckBox选中是，取到的值为“on”，如图跟踪发现：
所以，才用了IsNullOrEmpty这个函数，依据判空来确定是否选中。
但是这样写有个问题，在ModelState.IsValid()的模型验证中，一直无法通过，IsTop一直为false，为此，我干脆就把其去除掉验证：
ModelState.Remove("IsTop");//去除name=IsTop的checkbox的模型验证
5.使用Checkbox，还是要看给在数据表中为其定义的字段类型，Model中的指定类型和验证属性，如果你赋予了Value值，那么就在Controller中取值，Asp.Net Core中Checkbox默认是True和False的值，网上关于@Html.CheckBox()形式也行，你可以尝试跟踪变量值来判断如何处理，其宗旨就是根据具体条件来处理。
