记开发个人图书收藏清单小程序开发（五）Web开发

决定先开发Web端试试。

新增Web应用：

选择ASP.NET Core Web Application，填写好Name和Location，然后点击OK。

注意红框标出来的，基于.NET Core 2.1版本。登录认证用了微软自带的Identity。Template选择Web Application，也即最新的Razor Pages试图引擎模式。

创建完毕，因为该Template自带的bootstrap还是3.3.7，所以从中文网站下载最新的bootstrap 4.x，同时还需要下载的是popper js插件（如果用到dropdown组件的话，不大明白为何新版Bootstrap不自带这个）。_Layout中的css和js引用也需要同步更新一下，还有就是Navbar菜单需要更新，因为3.x和4.x用的class样式完全不一样。

下面给出示例代码：

 <nav class="navbar navbar-expand-lg navbar-light bg-light fixed-top">
     <div class="container">
         <a asp-page="/Index" class="navbar-brand">PTager Shelves</a>
         <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
             <span class="navbar-toggler-icon"></span>
         </button>
 
         <div class="collapse navbar-collapse" id="navbarSupportedContent">
             <ul class="navbar-nav mr-auto">
                 <li class="nav-item active">
                     <a class="nav-link" asp-page="/Index">Home</a>
                 </li>
                 <li class="nav-item">
                     <a class="nav-link" asp-page="/About">About</a>
                 </li>
                 <li class="nav-item">
                     <a class="nav-link" asp-page="/Contact">Contact</a>
                 </li>
             </ul>
             <partial name="_LoginPartial" />
         </div>
     </div>
 </nav>

到此，Web项目基本改造完成了。

当然，前面说到我还是用PTager的现有的登录DB做登录功能，很简单，直接修改appsettings.json文件中的DB连接字符串就好了（如果没有也没事，直接用本地的空DB，注册的时候会提示如何自己创建DB）。

 {
   "ConnectionStrings": {
     "DefaultConnection": "Server=.\\SQL2017;Database=PTager;Trusted_Connection=True;MultipleActiveResultSets=true"
   },
   "Logging": {
     "LogLevel": {
       "Default": "Warning"
     }
   },
   "AllowedHosts": "*"
 }

开始新增New Book功能。

先check豆瓣图书的api能不能正常调用。

在Pages文件夹下New Folder：Shelves，继续在Shelves文件夹New Item=>Razor Pages，Name直接改为：New。

为了接受豆瓣图书API获取的参数信息，先定义一个DoubanBookModel：

     public class DoubanBookModel
     {
         public string title { get; set; }
         public string subtitle { get; set; }
         public IEnumerable<string> author { get; set; }
         public IEnumerable<string> translator { get; set; }
         public string isbn13 { get; set; }
         public string isbn10 { get; set; }
         public string author_intro { get; set; }
         public string summary { get; set; }
         public string publisher { get; set; }
         public string binding { get; set; }
         public string origin_title { get; set; }
         public int pages { get; set; }
         public string image { get; set; }
         public string pubdate { get; set; }
         public string catalog { get; set; }
         public IEnumerable<TagItem> tags { get; set; }
         public RatingItem rating { get; set; }
 
         public sealed class TagItem
         {
             public int count { get; set; }
             public string name { get; set; }
             public string title { get; set; }
         }
         public sealed class SeriesItem
         {
             public int id { get; set; }
             public string title { get; set; }
         }
         public sealed class RatingItem
         {
             public int max { get; set; }
             public int min { get; set; }
             public int numRaters { get; set; }
             public string average { get; set; }
         }
     }

/Pages/Sheves/New.cshtml：

 @page
 @model NewModel
 @{
     ViewData["Title"] = "New Book";
 }
 <nav aria-label="breadcrumb">
     <ol class="breadcrumb">
         <li class="breadcrumb-item"><a asp-page="/Index">Home</a></li>
         <li class="breadcrumb-item"><a asp-page="/My Books/Index">My Books</a></li>
         <li class="breadcrumb-item active" aria-current="page">New Book</li>
     </ol>
 </nav>
 <form method="get">
     <div class="input-group input-group-lg mb-3">
         <div class="input-group-prepend">
             <span class="input-group-text" id="basic-addon1">ISBN #</span>
         </div>
         <input name="isbn" class="form-control" autofocus autocomplete="off" placeholder="ISBN #">
         <div class="input-group-append">
             <button class="btn btn-secondary btn-lg" type="submit">Search</button>
         </div>
     </div>
 </form>
 <hr />
 @if (Model.DoubanBook != null)
 {
     var item = Model.DoubanBook;
     <div class="media">
         @*<img class="align-self-start mr-3" src="@item.image" alt="Generic placeholder image">*@
         <div class="media-body">
             <h3 class="mt-0">@item.title<small class="ml-3">@item.subtitle</small></h3>
             <p><strong>Origin Title: </strong> @item.origin_title</p>
             <p><strong>Author: </strong> @string.Join("、", item.author)</p>
             <p><strong>Translator: </strong> @string.Join("、", item.translator)</p>
             <p>
                 <strong>Pubdate: </strong> @item.pubdate
                 <strong class="ml-3">Publisher: </strong> @item.publisher
                 <strong class="ml-3">Binding: </strong> @item.binding
                 <strong class="ml-3">Pages: </strong> @item.pages
             </p>
             <p>
                 <strong>ISBN: </strong> @item.isbn13
             </p>
             <p><strong class="mr-3">Author Intro:</strong> @item.author_intro</p>
             <p><strong class="mr-3">Summary:</strong>@item.summary</p>
             @foreach (var tag in item.tags)
             {
                 <span class="badge badge-info">@tag.name</span>
             }
         </div>
     </div>
     <hr />
     <form method="post">
         <input type="hidden" asp-page="IsbnNbr">
         <button class="btn btn-warning" type="submit">Add To My Books</button>
     </form>
 }

/Pages/Sheves/New.cshtml.cs：

     public class NewModel : PageModel
     {
         [BindProperty]
         public string IsbnNbr { get; set; }
         public DoubanBookModel DoubanBook { get; set; }
 
         public async Task OnGetAsync(string isbn)
         {
             IsbnNbr = isbn?.Trim() ?? string.Empty;
             if (validIsbnNbr(IsbnNbr))
             {
                 DoubanBook = await getDoubanBook();
             }
         }
         private async Task<DoubanBookModel> getDoubanBook()
         {
             var url = $"https://api.douban.com/v2/book/isbn/:{IsbnNbr}";
             var result = await HttpGetAsync(url);
             return JsonConvert.DeserializeObject<DoubanBookModel>(result);
         }
         public async Task<string> HttpGetAsync(string url, Encoding encoding = null)
         {
             using (var httpClient = new HttpClient())
             {
                 return await httpClient.GetStringAsync(url);
             }
         }
 
         private bool validIsbnNbr(string isbn)
             => !string.IsNullOrEmpty(IsbnNbr) && (IsbnNbr.Length ==  || IsbnNbr.Length == );
     }

好了，现在可以直接从豆瓣图书API获取到返回结果了，并且能展示在页面：