Blazor_WASM Part 2: Razor Syntax

Blazor_WASM Part 2: Razor Syntax

Razor is a markup syntax for embedding .NET-based code into web pages. Razor syntax consists of Razor markup, C#, and HTML. Razor can be found in the Razor Components file ( .razor). Razor syntax is similar to the templating engines of various JavaScript single-page application (SPA) frameworks (such as Angular, React, VueJs, and Svelte). This article introduces Razor common syntax for Razor files.

Razor Syntax Reference

Razor syntax

@*直接输出变量*@
<p> @Name</p>
@*如果就像输出@，则使用另个@*@
<p> @@Name</p>
@*如果是明显的邮箱格式则按邮箱格式输出*@
<p>[email protected]</p>
@*虽然是邮箱格式，但是两个@会重新将Name作为属性*@
<p>123@@Name.com</p>
@*如果是邮箱格式，但是想输出Name属性可以用括号*@
<p>123@(Name).com</p>

@*razor代码块*@
@*代码块内的 C# 代码不会呈现*@
@code {
  
    public string Name { set; get; } = "Test";

    public class Student
    { 
        public string Name { set; get; } 
        public string School{ set; get; }
    }

    string GenericMethod<T>()
    {
        return typeof(T).Name;
    }

    public Student stu = new Student() { Name = "Jerry" ,School = "yucai"};

    public int value { set; get; } = 3903;

}

Razor Implicit Expressions

@*隐式 Razor 表达式,可以直接使用.*@
@*但是隐式表达式不能使用泛型*@
<p>@stu.Name</p>

Razor display expressions

@*显式表达式*@
<p>@(stu.Name)显式</p>
<p>@(stu.Name + stu.School)显式</p>
@*可以调用私有方法*@
<p>@(GenericMethod<int>())泛型</p>

cycle

@*for循环*@
@for (int i = 0; i < 3; i++)
{
    <p>第@(i)个</p> 
    <p>@Name</p>
}

control structure

@if (value % 2 == 0)
{
    <p>The value was even.</p>
}
@*else 和 else if 不需要 @ 符号：*@

@if (value % 2 == 0)
{
    <p>The value was even.</p>
}
else if (value >= 1337)
{
    <p>The value is large.</p>
}
else
{
    <p>The value is odd and small.</p>
}


@switch (value)
{
    case 1:
        <p>The value is 1!</p>
        break;
    case 1337:
        <p>Your number is 1337!</p>
        break;
    default:
        <p>Your number wasn't 1 or 1337.</p>
        break;
}

using block

@*自动释放变量*@
@*@using (FileStream fs = new FileStream(".",FileMode.OpenOrCreate))
{
}

exception catch block

@try
{
    throw new InvalidOperationException("You did something invalid.");
}
catch (Exception ex)
{
    <p>The exception message: @ex.Message</p>
}
finally
{
}

characteristic

Each Razor will be compiled into a class, and a feature can be added to the class

@attribute [Authorize]

implement the interface

@implements IDisposable

inheritance class

@inherits CustomRazorPage<TModel>

defined as generic

@typeparam TEntity where TEntity : class

routing

Specifies that the Razor component should handle the request directly

@page "/test"

reference namespace

@using Microsoft.AspNetCore.Authorization

define namespace

The first letter of the namespace must be capitalized

@namespace Mynamespace

dependency injection

@inject Logger<Test> logger
等价于 private readonly Logger<Test> logger;
  public Test(Logger<Test> log)
  {
      logger = log
  }