ASP.NET Core Blazor依赖注入2：实现_blazor 注入开发-优快云博客

本文链接：https://blog.youkuaiyun.com/bdbox/article/details/129128055

文章展示了如何在BlazorApp5中创建一个IDateTime服务接口，然后实现这个接口为SystemDateTime类。接着，它解释了如何在Asp.NetCore7的Program.cs文件中进行依赖注入，将SystemDateTime注入到服务容器中。最后，文章给出了一个Blazor页面如何注入并使用这个服务来获取当前日期时间的例子。

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添加服务接口和服务类

using System;

namespace BlazorApp5.Services
{
    public interface IDateTime
    {
        DateTime Now { get; }
    }
}

using System;

namespace BlazorApp5.Services
{
    public class SystemDateTime : IDateTime
    {
        public DateTime Now
        {
            get { return DateTime.Now; }
        }
    }
}

依赖注入

Asp.net Core 7在 Program.cs中加入：

using BlazorApp5.Data;
using BlazorApp5.Services;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
//builder.Services.AddSingleton<WeatherForecastService>();

builder.Services.AddSingleton<IDateTime, SystemDateTime>(); 

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();

app.UseStaticFiles();

app.UseRouting();

app.MapBlazorHub();
app.MapFallbackToPage("/_Host");

app.Run();

在Blazor页面中调用服务

@using BlazorApp5.Services
@inject SystemDateTime systemDateTime

<div class="alert alert-secondary mt-4">
    <span class="oi oi-pencil me-2" aria-hidden="true"></span>
    <strong>@SetTitle()</strong>

    <span class="text-nowrap">
        Please take our
        <a target="_blank" class="font-weight-bold link-dark" href="https://go.microsoft.com/fwlink/?linkid=2186158">brief survey</a>
    </span>
    and tell us what you think.
</div>

@code {
    // Demonstrates how a parent component can supply parameters
    [Parameter]
    public string? Title { get; set; }

    public string SetTitle()
    {
        return systemDateTime.Now.ToString();
    }
}