如何实现DI服务全局注入？避免组件重复注入相同服务

有两种实用方案可以避免每次都重复编写相同的服务注入代码：

方案1：创建基础组件基类 #

把所有重复的注入声明封装到一个抽象基类中，后续组件直接继承这个基类，就能自动获取这些服务，无需重复注入。

public abstract class BaseComponent : ComponentBase
{
    [Inject] protected NotificationService NotificationService { get; set; } = default!;
    [Inject] protected DialogService DialogService { get; set; } = default!;
    [Inject] protected IJSRuntime JSRuntime { get; set; } = default!;
    [Inject] protected RegistrationService RegistrationService { get; set; } = default!;
    [Inject] protected NavigationManager NavigationManager { get; set; } = default!;
    [Inject] protected LocalStorageService LocalStorageService { get; set; } = default!;
}

使用时，组件只需继承基类即可直接调用服务：

@inherits BaseComponent

<button @onclick="ShowNotification">弹出通知</button>

@code {
    private void ShowNotification()
    {
        NotificationService.Show("这是来自基类的通知");
    }
}

注：将属性设为protected是为了让子类能访问，default!用于消除nullable上下文的非空警告。

方案2：封装组合服务 #

把常用服务打包成一个单一的组合服务类，组件只需注入这一个类，就能访问所有内部服务，适合不想用继承、追求低耦合的场景。

首先创建组合服务类：

public class AppCommonServices
{
    public NotificationService NotificationService { get; }
    public DialogService DialogService { get; }
    public IJSRuntime JSRuntime { get; }
    public RegistrationService RegistrationService { get; }
    public NavigationManager NavigationManager { get; }
    public LocalStorageService LocalStorageService { get; }

    public AppCommonServices(
        NotificationService notificationService,
        DialogService dialogService,
        IJSRuntime jsRuntime,
        RegistrationService registrationService,
        NavigationManager navigationManager,
        LocalStorageService localStorageService)
    {
        NotificationService = notificationService;
        DialogService = dialogService;
        JSRuntime = jsRuntime;
        RegistrationService = registrationService;
        NavigationManager = navigationManager;
        LocalStorageService = localStorageService;
    }
}

然后在Program.cs中注册这个组合服务：

builder.Services.AddScoped<AppCommonServices>();

组件中只需注入一次即可使用所有服务：

@inject AppCommonServices CommonServices

<button @onclick="OpenDialog">打开对话框</button>

@code {
    private void OpenDialog()
    {
        DialogService.Open("提示", "这是来自组合服务的对话框");
    }
}

两种方案各有优劣：基类方式更简洁，组件代码少；组合服务方式更灵活，避免了继承耦合，后续调整服务集合也更方便，可根据项目需求选择。

内容的提问来源于stack exchange，提问作者Stan Yurynets