篇(17)-Asp.Net Core入门实战-文章管理之文章类别的管理

如果要做一个CMS系统，那么文章管理算是入门，文章管理附带一个类别管理，用来对文章进行类别区分。所以，本章简单讲一些类别管理，这也是一个数据操作。

（1）.文章类别Sql表的建立

CREATE TABLE [dbo].[ArticleCategory](
[Id] [int] IDENTITY(1,1) NOT NULL,
[Title] [varchar](128) NOT NULL,
[ParentId] [int] NOT NULL,
[ClassList] [varchar](128) NULL,
[ClassLayer] [int] NULL,
[Sort] [int] NOT NULL,
[ImageUrl] [varchar](128) NULL,
[SeoTitle] [varchar](128) NULL,
[SeoKeywords] [varchar](256) NULL,
[SeoDescription] [varchar](512) NULL,
[IsDeleted] [bit] NOT NULL,
CONSTRAINT [PK_ARTICLECATEGORY] 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]
GO

 

（2）.文章类别的视图

（2.1）Create视图

@{ ViewData["Title"] = "新建文章分类"; }
@model ArticleCategory
<form action="/ArticleCategory/Create" method="post">
@Html.AntiForgeryToken()
<div>
<label asp-for="ParentId">父类别</label>
<div>
<label name="Parent_DisplayName" id="Parent_DisplayName">@ViewData["DisplayName"]</label>
<input type="hidden" asp-for="ParentId" id="ParentId" name="ParentId" value="@ViewData["ParentId"]" />
</div>
</div>
<div>
<label asp-for="Title">类别名称</label>
<div>
<input type="text" asp-for="Title" name="Title" placeholder="请输入类别名">
</div>
</div>
<div>
<label asp-for="Sort">排序</label>
<div>
<input type="text" asp-for="Sort" name="Sort" placeholder="排序">
</div>
</div>
<div>
<div>
<button type="submit">确定</button>
<button type="reset">重置</button>
</div>
</div>
</form>

 

（2.2）Edit视图

@{ ViewData["Title"] = "编辑菜单"; }
@model ArticleCategory
<form action="/ArticleCategory/Edit" method="post">
@Html.AntiForgeryToken()
<div>
<label asp-for="ParentId">父菜单</label>
<div>
<input type="text" asp-for="ParentId" name="ParentId" />
<input type="hidden" asp-for="Id" />
</div>
</div>
<div>
<label asp-for="Title">类别名成</label>
<div>
<input type="text" asp-for="Title" name="Title" placeholder="类别名成">
</div>
</div>
<div>
<label asp-for="Sort">排序</label>
<div>
<input type="text" asp-for="Sort" name="Sort" placeholder="排序">
</div>
</div>
<div>
<div>
<button type="submit">确定</button>
<button type="reset">重置</button>
</div>
</div>
</form>

 

（2.3）Index列表视图

单纯的列表在现实父类名称时，显示的还是Id值，看第一步的表结构可以发现，这个字段是ParentId，我们得显示成名称才行。

@using Humanizer;
@using RjWebCms.Db;
@using RjWebCms.Models.Articles;
@using RjWebCms.Common;
@model PaginatedList<ArticleCategoryView>
@{
ViewData["Title"] = "文章类别列表";
}
@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: "/ArticleCategory/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="ArticleCategory" 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>&#x2714;</td>
<td><a asp-action="Index" asp-route-sortOrder="@ViewData["NameSortParm"]" asp-route-currentFilter="@ViewData["CurrentFilter"]">类别名称</a></td>
<td>父类名称</td>
<td><a asp-action="Index" asp-route-sortOrder="@ViewData["DateSortParm"]" asp-route-currentFilter="@ViewData["CurrentFilter"]">序号</a></td>
<td>操作</td>
</tr>
@foreach (var item in Model)
{
if (item.ParentId == 0)
{
<tr>
<td><input type="checkbox" class="done-checkbox" name="chk_ids" value="@item.Id"></td>
<td>@item.Title</td>
<td>\</td>
<td>@item.Sort</td>
<td>
<a asp-action="Create" asp-route-id="@item.Id">Add</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>
}
else
{
<tr>
<td><input type="checkbox" class="done-checkbox" name="chk_ids" value="@item.Id"></td>
<td>@item.Title</td>
@*<td>@Html.Action("GetParentName",new { id=item.ParentId})</td>*@
<td>@item.ParentName</td>
<td>@item.Sort</td>
<td>
<a asp-action="Create" asp-route-id="@item.Id">Add</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>

 

所以，需要编写ViewModel是实现，这在前面章节中详细讲过。

（3）.Model对象的编码实现。

（3.1）表的直接映射对象ArticleCategory.cs

/// <summary>

/// 文章类别

/// </summary>

public class ArticleCategory

{

/// <summary>

/// 主键

/// </summary>

[Key]

public Int32 Id { get; set; }

/// <summary>

/// 分类标题

/// </summary>

[Required]

public String Title { get; set; }

/// <summary>

/// 父分类ID

/// </summary>

[Required]

public Int32 ParentId { get; set; }

/// <summary>

/// 类别ID列表(逗号分隔开)

/// </summary>

public String ClassList { get; set; }

/// <summary>

/// 类别深度

/// </summary>

public Int32? ClassLayer { get; set; }

/// <summary>

/// 排序

/// </summary>

[Required]

public Int32 Sort { get; set; }

/// <summary>

/// 分类图标

/// </summary>

public String ImageUrl { get; set; }

/// <summary>

/// 分类SEO标题

/// </summary>

public String SeoTitle { get; set; }

/// <summary>

/// 分类SEO关键字

/// </summary>

public String SeoKeywords { get; set; }

/// <summary>

/// 分类SEO描述

/// </summary>

public String SeoDescription { get; set; }

/// <summary>

/// 是否删除

/// </summary>

[Required]

public Boolean IsDeleted { get; set; }

}

（3.2）. ArticleCategoryView.cs 也就是文章类别列表页的ViewModel代码
public class ArticleCategoryView
{
public int Id { get; set; }
public string Title { get; set; }
public int ParentId { get; set; }
public string ParentName { get; set; }
public int Sort { get; set; }
}

（4）.Controller的编码实现
public class ArticleCategoryController : Controller
{
private readonly IArticleCategoryService _articleCategoryService;
private readonly AppDbContext _appDbContext;
public ArticleCategoryController(IArticleCategoryService articleCategoryService, AppDbContext appDbContext)
{
_appDbContext = appDbContext;
_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 == "sort" ? "sort_desc" : "sort";
if (searchString != null)
{
pageNumber = 1;
}
else
{
searchString = currentFilter;
}

ViewData["CurrentFilter"] = searchString;
var articleCategories = from s in _appDbContext.ArticleCategory.OrderBy(s=>s.Id)
join p in _appDbContext.ArticleCategory on s.ParentId equals p.Id into T1
from m in T1.DefaultIfEmpty()
select new ArticleCategoryView
{
Id = s.Id,
Title = s.Title,
ParentId = s.ParentId,
ParentName = m.Title,
Sort = s.Sort
};
if (!string.IsNullOrEmpty(searchString))
{
articleCategories = articleCategories.Where(s => s.Title.Contains(searchString));
}
switch (sortOrder)
{
case "name_desc":
articleCategories = articleCategories.OrderByDescending(s => s.Title);
break;
case "sort":
articleCategories = articleCategories.OrderBy(s => s.Sort);
break;
case "sort_desc":
articleCategories = articleCategories.OrderByDescending(s => s.Sort);
break;
default:
articleCategories = articleCategories.OrderBy(s => s.Title);
break;
}

int pageSize = 4;
return View(await PaginatedList<ArticleCategoryView>.CreateAsync(articleCategories.AsNoTracking(), pageNumber ?? 1, pageSize));
}

[HttpGet]
public async Task<IActionResult> Create(int id)
{
if (id != 0)
{
var articleCategory = await _articleCategoryService.FindArticleCategoryAsync(id);
if (articleCategory != null)
{
ViewData["DisplayName"] = articleCategory.Title;
ViewData["ParentId"] = articleCategory.Id; //增加子目录时，以id作为子目录的parentid
}
}
else
{
ViewData["DisplayName"] = "顶级根目录";
ViewData["ParentId"] = 0;
}
return View();
}

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create(int id, ArticleCategory articleCategory)
{
//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
if (id != 0)
articleCategory.ParentId = id;
if (ModelState.IsValid)
{
var successful = await _articleCategoryService.AddArticleCategoryAysnc(articleCategory);
if (successful)
return RedirectToAction("Index");
else
return BadRequest("失败");
}
return View(articleCategory);
}

[HttpGet]
public async Task<IActionResult> Edit(int id)
{
if (string.IsNullOrEmpty(id.ToString()))
return NotFound();
var articleCategory = await _articleCategoryService.FindArticleCategoryAsync(id);
if (articleCategory == null)
return NotFound();
return View(articleCategory);
}

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(int id, ArticleCategory articleCategory)
{
if (id != articleCategory.Id)
{
return NotFound();
}

if (ModelState.IsValid)
{
try
{
var result = await _articleCategoryService.UpdateArticleCategoryAsync(id, articleCategory);
}
catch (Exception ex)
{
return BadRequest("编辑失败");
}
return RedirectToAction("Index");
}
return View(articleCategory);
}
[HttpGet]

public async Task<IActionResult> Delete(int id)
{
var result = await _articleCategoryService.DeleteArticleCategoryAsync(id);
if (result)
return RedirectToAction("Index");
else
return BadRequest("删除失败");
}

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> DeleteAll(string[] ids)
{
int countSuccessDel = 0;//记录删除成功的数据条数
int countFailedDel = 0;//记录删除成功的数据条数
foreach (string id in ids)
{
if (await _articleCategoryService.DeleteArticleCategoryAsync(int.Parse(id)))
countSuccessDel++;
else
countFailedDel++;
}

if (countSuccessDel > 0)
return RedirectToAction("Index");
else
return BadRequest("删除失败");
}

public async Task<IActionResult> Details(int id)
{
if (string.IsNullOrEmpty(id.ToString()))
return NotFound();
var articleCategory = await _articleCategoryService.FindArticleCategoryAsync(id);
if (articleCategory == null)
return NotFound();
return View(articleCategory);
}

[HttpGet]
public async Task<IActionResult> GetCategory()
{
var items = await _articleCategoryService.GetArticleCategory();
return View(items);
}
public IActionResult GetParentName(int id)
{
var category = _appDbContext.ArticleCategory.Where(x => x.Id == id).FirstOrDefault();
if (category != null)
return Content(category.Title);
else
return Content("");
}
}

 

注意，在Index的Action中的我用了个简单的Linq关联查询

因为，父Id与Id都是存在一张表中，关联子查询在使用时要用到：from m in T1.DefaultIfEmpty() 这一句，可以将空也计算在内，否则，会排除掉最前面2行（下图），我的本意sql语句是：

Select a.Id,a.Title,a.parentId,b.Title as ParentName,a.sort from ArticleCategory a

Left join ArticleCategory b on a.ParentId = b.Id ，这样可以将父Id的名称作为一个新列放在查询表中。

要注意在关键地方的改变，其他内容与将菜单功能时类似。

（5）.服务层代码实现

（5.1）接口代码

public interface IArticleCategoryService
{
Task<ArticleCategory[]> GetArticleCategory();
Task<ArticleCategory[]> GetArticleCategoryByParentId(int pId);
Task<ArticleCategory> FindArticleCategoryAsync(int Id);
Task<bool> AddArticleCategoryAysnc(ArticleCategory menu);
Task<bool> UpdateArticleCategoryAsync(int id, ArticleCategory menu);
Task<bool> DeleteArticleCategoryAsync(int Id);
}

 

（5.2）实现代码

public class ArticleCategoryService : IArticleCategoryService
{
private readonly AppDbContext _appDbContext;
public ArticleCategoryService(AppDbContext appDbContext)
{
_appDbContext = appDbContext;
}
public async Task<bool> AddArticleCategoryAysnc(ArticleCategory articleCategory)
{
articleCategory.IsDeleted = false;
if (articleCategory.ParentId == 0)
articleCategory.ClassLayer = 1;
else
articleCategory.ClassLayer = 2;
await _appDbContext.ArticleCategory.AddAsync(articleCategory);
var result = await _appDbContext.SaveChangesAsync();
return result == 1;
}

public async Task<bool> DeleteArticleCategoryAsync(int Id)
{
var articleCategory = await _appDbContext.ArticleCategory.FirstOrDefaultAsync(x => x.Id == Id);
if (articleCategory != null)
{
_appDbContext.ArticleCategory.Remove(articleCategory);
}
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)
}

public async Task<ArticleCategory> FindArticleCategoryAsync(int Id)
{
var item = await _appDbContext.ArticleCategory.Where(x => x.Id == Id).FirstOrDefaultAsync();
return item;
}

public async Task<ArticleCategory[]> GetArticleCategory()
{
var items = await _appDbContext.ArticleCategory.Where(x => x.IsDeleted==false).OrderByDescending(x => x.Sort).ToArrayAsync();
return items;
}

public async Task<ArticleCategory[]> GetArticleCategoryByParentId(int pId)
{
var items = await _appDbContext.ArticleCategory.Where(x => x.ParentId == pId).OrderByDescending(x => x.Sort).ToArrayAsync();
return items;
}

public async Task<bool> UpdateArticleCategoryAsync(int id, ArticleCategory articleCategory)
{
var oldArticleCategory = await FindArticleCategoryAsync(id); //找出旧对象
//将新值赋到旧对象上
oldArticleCategory.Title = articleCategory.Title;
oldArticleCategory.ParentId = articleCategory.ParentId;
oldArticleCategory.Sort = articleCategory.Sort;
//对旧对象执行更新
_appDbContext.Entry(oldArticleCategory).State = EntityState.Modified;
var result = await _appDbContext.SaveChangesAsync();
return result == 1;
}
}

 

至此，文章管理功能编写完成。通篇只有2个主要知识点：linq子查询和ViewModel显示