Laravel：服务提供者中接口的条件绑定未按预期工作

Question

我正在使用 Laravel（版本 11）并尝试有条件地将接口（

DashboardStrategy

）绑定到不同的具体实现（

DashboardWebService

和

DashboardApiService

），具体取决于正在解析的控制器（

DashboardWebController

或

DashboardApiController） 

）。

问题：

我遇到以下错误：

Target [App\Services\Dashboard\DashboardStrategy] is not instantiable while building [App\Http\Controllers\Dashboard\DashboardWebController].

我已按如下方式设置我的

AppServiceProvider

：

public function boot(): void
{
    // Inject DashboardApiService for DashboardStrategy when resolving DashboardApiController
    $this->app->when(DashboardApiController::class)
        ->needs(DashboardStrategy::class)
        ->give(DashboardApiService::class);

    // Inject DashboardWebService for DashboardStrategy when resolving DashboardWebController
    $this->app->when(DashboardWebController::class)
        ->needs(DashboardStrategy::class)
        ->give(DashboardWebService::class);
}

public function register(): void
{
    $this->app->singleton(DashboardApiService::class, function (Application $app) {
        return new DashboardApiService($app->make(ImageService::class));
    });

    $this->app->singleton(DashboardWebService::class, function (Application $app) {
        return new DashboardWebService($app->make(ImageService::class));
    });
}

尽管如此设置，Laravel 仍然会抛出上述错误。

我尝试过的：

1. 将绑定简化如下，并且有效：

   $this->app->singleton(DashboardStrategy::class, DashboardApiService::class);
   

   但是，这会迫使两个控制器使用相同的服务，这是我想避免的。

2. 清除所有缓存：

   php artisan config:cache
   php artisan route:cache
   php artisan view:cache
   php artisan cache:clear
   php artisan clear-compiled
   

3. 仔细检查

   DashboardServiceManager

   中的构造函数以确保它期待

   DashboardStrategy

   :

   public function __construct(DashboardStrategy $dashboardStrategy)
   {
       $this->dashboardStrategy = $dashboardStrategy;
   }
   

问题：

如何正确设置条件绑定，以便在解析

DashboardWebService

时注入

DashboardWebController

，并在解析

DashboardApiService

时注入

DashboardApiController

？

Laravel 中是否有更好的方法来处理这种情况，或者我在当前的实现中遗漏了一些东西？

Answer 1

我认为

give()

需要一个实例，因此您可以尝试这种格式，因为您已经声明了单例

public function boot(): void
{
    // Inject DashboardApiService for DashboardStrategy when resolving DashboardApiController
    $this->app->when(DashboardApiController::class)
        ->needs(DashboardStrategy::class)
        ->give(app(DashboardApiService::class));

    // Inject DashboardWebService for DashboardStrategy when resolving DashboardWebController
    $this->app->when(DashboardWebController::class)
        ->needs(DashboardStrategy::class)
        ->give(app(DashboardWebService::class));
}