dependency-injection

问题 I'm getting null injected into my constructor that has a dependency which I forgot to register. In the below example dependency would be null when you forget to register IDepencency in the startup class public class AzureFunction { public AzureFunction(IDepencency dependency) { } } I expected it to work the same as in .net core DI. Is this expected behavior? And can I maybe change a setting to enable throwing exceptions? Edit: After reading HariHaran's answer, I realized it's only happening

问题 I am trying to refactor some application to use Spring DI instead of plain java and stuck with the issue. Basically i have a class with several constructors: public MyClass() { this(new A()); } public MyClass(A a) { this(a, new B())); } public MyClass(String string) { this(new A(string)); } public MyClass(A a, B b) { this.a = a; this.c = a.getC(); this.b = b; this.d = b.getD(); } public MyClass(A a, B b, D d) { this.a = a; this.c = a.getC(); this.b = b; this.d = d; } These constructors are

问题 I am trying to refactor some application to use Spring DI instead of plain java and stuck with the issue. Basically i have a class with several constructors: public MyClass() { this(new A()); } public MyClass(A a) { this(a, new B())); } public MyClass(String string) { this(new A(string)); } public MyClass(A a, B b) { this.a = a; this.c = a.getC(); this.b = b; this.d = b.getD(); } public MyClass(A a, B b, D d) { this.a = a; this.c = a.getC(); this.b = b; this.d = d; } These constructors are

问题 Everywhere I can see three main approaches to create clients (basic, named, typed) in DI, but I have found nowhere if to inject IHttpClientFactory or HttpClient (both possible). Q1 : What is the difference between injecting IHttpClientFactory or HttpClient please? Q2 : And if IHttpClientFactory is injected, should I use factory.CreateClient() for each call? 回答1: Summary HttpClient can only be injected inside Typed clients for other usages, you need IHttpClientFactory In both scenarios, the

问题 Everywhere I can see three main approaches to create clients (basic, named, typed) in DI, but I have found nowhere if to inject IHttpClientFactory or HttpClient (both possible). Q1 : What is the difference between injecting IHttpClientFactory or HttpClient please? Q2 : And if IHttpClientFactory is injected, should I use factory.CreateClient() for each call? 回答1: Summary HttpClient can only be injected inside Typed clients for other usages, you need IHttpClientFactory In both scenarios, the

问题 I've created a custom library which automatically sets up Polly policies for specific services which depend on HttpClient . This is done using the IServiceCollection extension methods and the typed client approach. A simplified example: public static IHttpClientBuilder SetUpFooServiceHttpClient(this IServiceCollection services) { return services .AddHttpClient<FooService>() .AddPolicyHandler(GetRetryPolicy()); } The example service: public class FooService { private readonly HttpClient

问题 I have a .NET core project and am trying to create a custom policy using AuthorizationOptions as shown in the documentation located here: ASP.NET.Core Authorization - Dependency Injection in requirement handlers The examples show setting up an authorization requirement with 1 parameter - a simple int value. My custom requirement requires a string parameter as well as a DbContext object. I want to inject the DbContext into the requirement's constructor at runtime. I am using the Autofac

问题 Would it be a bad idea to pass anything that could possibly not work in the future to a class? For instance, passing a database connection (or anything that can possibly have it's methods rendered useless) to multiple classes? With JavaScript, these are passed by reference, therefore if the database connection is canceled outside of the class, the object within the classes wouldn't work? Now would this be bad, seeing now that all the models and things which use the database in methods will

问题 Would it be a bad idea to pass anything that could possibly not work in the future to a class? For instance, passing a database connection (or anything that can possibly have it's methods rendered useless) to multiple classes? With JavaScript, these are passed by reference, therefore if the database connection is canceled outside of the class, the object within the classes wouldn't work? Now would this be bad, seeing now that all the models and things which use the database in methods will

问题 Would it be a bad idea to pass anything that could possibly not work in the future to a class? For instance, passing a database connection (or anything that can possibly have it's methods rendered useless) to multiple classes? With JavaScript, these are passed by reference, therefore if the database connection is canceled outside of the class, the object within the classes wouldn't work? Now would this be bad, seeing now that all the models and things which use the database in methods will