问题描述
program.cs调用CreateHostBuilder.Build（）时出现以下异常：
system.invalidOperationException：无法解析类型的服务 尝试激活时“ web_application.Models.postStatus” “ web_application.Services.Updates.PostingStatusUpdater”。
以下是完整错误，但正在Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSites（Type serviceType，Type ImplementationType，CallSiteChain callSiteChain，ParameterInfo [] parameters，Boolean throwIfCallSiteNotFound）中抛出
我搜索了为该依赖项注入dll打开详细日志记录的方法或调试该依赖项注入框架的方法，但找不到相应的答案。如果有人在程序的此阶段知道如何启用详细日志记录，请也免费提供帮助！ 这是在Startup.cs中注册服务的方式：
using System;
...
namespace web_application
{
public class Startup
{
...
public void ConfigureServices(IServiceCollection services)
{
services.AddScoped<IUpdateService<postStatus>,PostingStatusUpdater>();
...
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app,IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseDatabaseErrorPage();
}
...
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
});
}
}
}
postStatus是一个枚举，我首先想到的是DI注册可能由于与之相关的事情而失败。
要注册的实际类是从实现通用接口的基类派生的。
通用接口：
using System;
using System.Threading.Tasks;
using System.Collections.Generic;
using web_application.Models;
namespace web_application.Services.Updates{
public interface IUpdateService<T>{
bool runPreUpdateChecks(out IList<string> allFailedChecks);
void runPostCheckHooks();
bool tryPerformUpdate(T intialState,T FinalState,Action runUpdate,out IList<string> failureReasons);
Task<(bool success,IList<string> updateFailureReasons)> tryPerformUpdateAsync(T intialState,Task runUpdateAsync);
}
}
基类：
using System;
using System.Threading.Tasks;
using web_application.Models;
using System.Collections.Generic;
namespace web_application.Services.Updates{
public abstract class BaseStatusUpdater<T> : IUpdateService<T>
{
public T initStatus {get; private set;}
public T finalStatus {get; private set;}
// Todo: Add update check attributes
public List<PreUpdateCheck<T>> preUpdateChecks = new List<PreUpdateCheck<T>>();
public IList<Action> postUpdateHooks = new List<Action>();
public BaseStatusUpdater(T initStatus,T finalStatus){
this.initStatus = initStatus;
this.finalStatus = finalStatus;
}
/// <summary>
/// Runs preupdate checks and returns every check that Failed (no short circuit)
/// Returns a list of Failed checks on failure.
/// </summary>
public bool runPreUpdateChecks(out IList<string> allFailedChecks){
allFailedChecks = new List<string>(preUpdateChecks.Count);
var allChecksPassed = true;
foreach(var check in preUpdateChecks){
if(!check.run()){
allFailedChecks.Add(check.failureReason);
allChecksPassed = false;
}
}
return allChecksPassed;
}
/// <summary>
/// Run only actions that are one-off,and don't cascade into other
/// actions that may require custom error handling.
/// </summary>
public void runPostCheckHooks(){
foreach(var hook in postUpdateHooks){
hook();
}
}
public bool tryPerformUpdate(T intialState,out IList<string> updateFailureReasons){
if(!runPreUpdateChecks(out updateFailureReasons)){
return false;
}
runUpdate();
runPostCheckHooks();
return true;
}
// https://stackoverflow.com/questions/18716928/how-to-write-an-async-method-with-out-parameter
public async Task<(bool success,IList<string> updateFailureReasons)>
tryPerformUpdateAsync(T intialState,Task runUpdateAsync)
{
IList<string> updateFailureReasons = new List<string>(preUpdateChecks.Count);
if(!runPreUpdateChecks(out updateFailureReasons)){
return (false,updateFailureReasons);
}
await runUpdateAsync;
runPostCheckHooks();
return (true,updateFailureReasons);
}
}
}
正在为IUpdateService注册的类
using System;
using web_application.Models;
using System.Collections.Generic;
namespace web_application.Services.Updates{
// Make this a singleton on injection to get this so that we don't keep constructing the things
// in the constructor every time its called? Or store the static logic somewhere else
using vpStatus = postStatus;
public class PostingStatusUpdater : BaseStatusUpdater<postStatus>
{
public PostingStatusUpdater(vpStatus vpsInitial,vpStatus vpsFinal)
: base(vpsInitial,vpsFinal)
{
Func<(bool,string)> isMovePermitted = () => {
if(UpdateLogic.permittedStatusChanges
.Contains(new UpdateLogic.statusPair(base.initStatus,vpsFinal))){
return (true,string.Empty);
}
return (false,"Cannot mark post as \"" + vpsFinal.ToString() + " since it is currently marked as "
+ "\"" + vpsInitial.ToString() + "\"");
};
var check1 = new PreUpdateCheck<vpStatus>(isMovePermitted);
base.preUpdateChecks.Add(check1);
}
}
}
没有关于此的编译时错误或警告，我一直在研究以确保以前未解决此问题，但是我找不到确切解决此问题的问题，因此我想将其发布以寻求帮助。
谢谢。
完整错误：
引发的异常：“ System.AggregateException” Microsoft.Extensions.DependencyInjection.dll：“某些服务不是 能够被构造”发现内部异常，有关更多详细信息，请参见变量窗口中的$ exception。 最内在的例外 system.invalidOperationException：无法解析类型的服务 尝试激活时“ web_application.Models.postStatus” “ web_application.Services.Updates.PostingStatusUpdater”。 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSites（Type serviceType，Type ImplementationType，CallSiteChain，callSiteChain， ParameterInfo []参数，布尔值throwIfCallSiteNotFound）位于 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite（ResultCache 生命周期，类型serviceType，类型ImplementationType，CallSiteChain callSiteChain） Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact（ServiceDescriptor 描述符，类型serviceType，CallSiteChain，callSiteChain，Int32插槽） 在 Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite（ServiceDescriptor serviceDescriptor，CallSiteChain callSiteChain） Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.ValidateService（ServiceDescriptor 描述符）
解决方法
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