ASP.NET Core-Razor页面

2019-11-02 来源: WilsonPan 发布在  https://www.cnblogs.com/WilsonPan/p/11775622.html

准备工作

  1. 初始化空的项目(终端输入:dotnet new web -n=Razor)
  2. Nuget添加Microsoft.EntityFrameworkCore.SqlServer 和 Microsoft.EntityFrameworkCore.Design 
  3. 添加必要服务

   ConfigureServices添加Razor支持

public void ConfigureServices(IServiceCollection services)
{
    services.AddRazorPages();
}

  修改app.UseEndpoints为

app.UseEndpoints(endpoints =>
{
    endpoints.MapRazorPages();
});

添加数据库

 1. 添加模型
[Table("Book")]
public class Book
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    [Display(Name = "书名")]
    [Required(ErrorMessage = "书名不能为空")]
    [StringLength(, ErrorMessage = "书名最大长度为50")]
    public string Name { get; set; }

    [Display(Name = "单价")]
    [Column(TypeName = "decimal(18, 2)")]
    [Range(, ErrorMessage = "单价范围只能在(0.01 ~ 10000)"), DataType(DataType.Currency)]
    public decimal UnitPrice { get; set; }

    [Display(Name = "出版日期")]
    [DataType(DataType.Date), DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}")]
    public DateTime PublicationDate { get; set; }

    [Display(Name = "创建时间")]
    [DataType(DataType.DateTime), DisplayFormat(DataFormatString = "{0:yyyy-MM-dd HH:mm:ss}")]
    public DateTime CreateTime { get; set; }

    [Display(Name = "最后更新时间")]
    [DataType(DataType.DateTime), DisplayFormat(DataFormatString = "{0:yyyy-MM-dd HH:mm:ss}")]
    public DateTime? LastUpdateTime { get; set; }
}

2. 添加DbContext

public class RazorDbContext : DbContext
{
    public RazorDbContext(DbContextOptions<RazorDbContext> options)
        : base(options)
    {

    }

    public DbSet<Razor.Models.Book> Book { get; set; }
}

3. 安装dotnet-ef(全局安装),终端输入

dotnet tool install --global dotnet-ef
4. 添加迁移
dotnet ef migrations add InitialDb

5. 更新到数据库

dotnet ef database update InitialDb

6. 添加种子数据

public static class SeedData
{
    public static void Initialize(IServiceProvider serviceProvider)
    {
        var options = serviceProvider.GetRequiredService<DbContextOptions<RazorDbContext>>();
        using (var context = new RazorDbContext(options))
        {
            if (context.Book.Any())
            {
                return;
            }

            context.Book.AddRange(
                new Models.Book
                {
                    Name = "算法之美",
                    UnitPrice = 26.99m,
                    PublicationDate = DateTime.Parse("2016-08-20"),
                    CreateTime = DateTime.Now
                },
                new Models.Book
                {
                    Name = "大话设计模式",
                    UnitPrice = 28.03m,
                    PublicationDate = DateTime.Parse("2015-06-12"),
                    CreateTime = DateTime.Now
                },
                new Models.Book
                {
                    Name = "幸福的陷阱",
                    UnitPrice = 30.59m,
                    PublicationDate = DateTime.Parse("2018-09-13"),
                    CreateTime = DateTime.Now
                },
                new Models.Book
                {
                    Name = "墨菲定律",
                    UnitPrice = 32.12m,
                    PublicationDate = DateTime.Parse("2018-09-13"),
                    CreateTime = DateTime.Now
                }
            );

            context.SaveChanges();
        }
    }
}

经过上面的步骤就可以在程序中使用数据库

Razor页面

一、路由
@page指令
  1. 必须是页面上的第一个 Razor 指令
  2. 默认情况,Url根据文件夹层次结构生成,也可以在@page 后面指定路由
  3. 可以对参数约束,例如:{id:int}

二、读取数据(以上面模型为例)

  1. 创建Index页面

dotnet new page -o=Pages -na="Razor.Pages" -n="Index"

  2. PageModel 的OnGet读取数据

public class IndexModel : PageModel
{
    private readonly Data.RazorDbContext _dbContext;
    public IndexModel(Data.RazorDbContext dbContext)
    {
        _dbContext = dbContext;
    }

    public List<Models.Book> Books { get; set; }

    public IActionResult OnGet()
    {
        if (_dbContext == null)
        {
            return NotFound();
        }

        Books = _dbContext.Book
                            .AsNoTracking()
                            .ToList();
        return Page();
    }
}

  3. 页面展示数据

@page
@model IndexModel
@{
    ViewData["Title"] = "图书管理";
}
<table class="table table-bordered text-center">
    <thead>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.Books[].Name)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Books[].UnitPrice)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Books[].PublicationDate)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Books[].CreateTime)
            </th>
            <th >
                @Html.DisplayNameFor(model => model.Books[].LastUpdateTime)
            </th>
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model.Books)
        {
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => item.Name)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.UnitPrice)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.PublicationDate)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.CreateTime)
                </td>
                <td>
                    @Html.DisplayFor(modelItem => item.LastUpdateTime)
                </td>
                <td>
                    <a asp-page="./Edit" asp-route-id="@item.Id">编辑</a> |
                    <a asp-page="./Delete" asp-route-id="@item.Id">删除</a>
                </td>
            </tr>
        }
    </tbody>
</table>

三、更新数据

  1. 创建Edit页面

dotnet new page -o=Pages -na="Razor.Pages" -n="Edit"

  2. PageModel拉去数据

public IActionResult OnGet(int? id)
{
    if (id == null)
    {
        return NotFound();
    }

    Book = _dbContext.Book
                     .AsNoTracking()
                     .FirstOrDefault(m => m.Id == id);

    if(Book == null)
    {
        return NotFound();
    }

    return Page();
}

  3. 编辑Edit页面

@page "{id:int}"
@model Razor.Pages.EditModel
@{
    ViewData["Title"] = "编辑书本";
}
<div class="row">
    <div class="col-md-4">
        <form method="post">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <input type="hidden" asp-for="Book.Id" />
            <div class="form-group">
                <label asp-for="Book.Name" class="control-label"></label>
                <input asp-for="Book.Name" class="form-control" />
                <span asp-validation-for="Book.Name" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Book.UnitPrice" class="control-label"></label>
                <input asp-for="Book.UnitPrice" class="form-control" />
                <span asp-validation-for="Book.UnitPrice" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Book.PublicationDate" class="control-label"></label>
                <input asp-for="Book.PublicationDate" class="form-control" />
                <span asp-validation-for="Book.PublicationDate" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="保存" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

  4. OnPost处理请求

public IActionResult OnPost()
{
    if (!ModelState.IsValid)
    {
        return Page();
    }

    var model = _dbContext.Book.FirstOrDefault(m => m.Id == Book.Id);

    if (model == null)
    {
        return NotFound();
    }

    model.Name = Book.Name;
    model.PublicationDate = Book.PublicationDate;
    model.UnitPrice = Book.UnitPrice;

    _dbContext.SaveChanges();

    return RedirectToPage("Index");
}

用asp-for生成的输入框,会加上客户端验证,查看原代码可以发现

<input class="form-control" type="text" data-val="true" data-val-length="书名最大长度为50" data-val-length-max="50" data-val-required="书名不能为空" id="Book_Name" maxlength="50" name="Book.Name" value="大话设计模式" />

它是根据模型定义的验证,生成属性,然后用jquery-validation验证,这样我们没有写一行前端代码就能达到客户端验证效果,微软真的把DRY做到极致。当然后端的验证也是不能漏的

筛选器

Razor 页面筛选器提供的以下方法可在全局或页面级应用:

同步方法:

  • OnPageHandlerSelected:在选择处理程序方法后但在模型绑定发生前调用。
  • OnPageHandlerExecuting:在执行处理器方法前,模型绑定完成后调用。
  • OnPageHandlerExecuted:在执行处理器方法后,生成操作结果前调用。

异步方法:

  • OnPageHandlerSelectionAsync:在选择处理程序方法后,但在模型绑定发生前,进行异步调用。
  • OnPageHandlerExecutionAsync:在调用处理程序方法前,但在模型绑定结束后,进行异步调用。
一、全局筛选器
  1. 定义GlobalPageFilter,实现IPageFilter接口
public class GlobalPageFilter : IPageFilter
{
    private readonly ILogger _logger;

    public GlobalPageFilter(ILoggerFactory loggerFactory)
    {
        _logger = loggerFactory.CreateLogger<GlobalPageFilter>();
    }

    public void OnPageHandlerExecuted(PageHandlerExecutedContext context)
    {
        _logger.LogDebug("Global Filter OnPageHandlerSelected called.");
    }

    public void OnPageHandlerExecuting(PageHandlerExecutingContext context)
    {
        _logger.LogDebug("Global Filter OnPageHandlerExecuting called.");
    }

    public void OnPageHandlerSelected(PageHandlerSelectedContext context)
    {
        _logger.LogDebug("Global Filter OnPageHandlerSelected called.");
    }
}

  2. ConfigureServices添加筛选器

services.AddMvc(options =>
{
    options.Filters.Add<Filters.GlobalPageFilter>();
});
二、特定PageModel筛选器
  在PageModel里面重载
public override void OnPageHandlerSelected(Microsoft.AspNetCore.Mvc.Filters.PageHandlerSelectedContext context)
{
    _logger.LogDebug("OnPageHandlerSelected");
}
//在执行处理器方法前,模型绑定完成后调用
public override void OnPageHandlerExecuting(Microsoft.AspNetCore.Mvc.Filters.PageHandlerExecutingContext context)
{
    _logger.LogDebug("OnPageHandlerExecuting");
}
//在执行处理器方法后,生成操作结果前调用
public override void OnPageHandlerExecuted(Microsoft.AspNetCore.Mvc.Filters.PageHandlerExecutedContext context)
{
    _logger.LogDebug("OnPageHandlerExecuted");
}

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