![](/img/trans.png)
[英]The constraint reference 'string' could not be resolved to a type. type with 'Microsoft.AspNetCore.Routing.RouteOptions.ConstraintMap'
[英]The constraint reference 'string' could not be resolved to a type. (netcoreapp3.0)
我有一個錯誤。 這是我的啟動課。
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
}
public void Configure(IApplicationBuilder app)
{
app.UseDeveloperExceptionPage();
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
當前技術“netcoreapp3.0”和我的控制器是。
[Route("api/[controller]")]
[ApiController]
public class ExampleController : ControllerBase
{
[HttpGet("request")]
public ActionResult Index()
{
return Ok();
}
}
這是我的錯誤。 我找不到解決方案,我什至不知道這到底是什么。 所以我們在這里。
System.InvalidOperationException: The constraint reference 'string' could not be resolved to a type. Register the constraint type with 'Microsoft.AspNetCore.Routing.RouteOptions.ConstraintMap'.
at Microsoft.AspNetCore.Routing.DefaultParameterPolicyFactory.Create(RoutePatternParameterPart parameter, String inlineText)
at Microsoft.AspNetCore.Routing.ParameterPolicyFactory.Create(RoutePatternParameterPart parameter, RoutePatternParameterPolicyReference reference)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.CreateCandidate(Endpoint endpoint, Int32 score)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.CreateCandidates(IReadOnlyList`1 endpoints)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.AddNode(DfaNode node, DfaState[] states, Int32 exitDestination)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.AddNode(DfaNode node, DfaState[] states, Int32 exitDestination)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.<AddNode>g__Transition|19_0(DfaNode next, <>c__DisplayClass19_0& )
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.AddNode(DfaNode node, DfaState[] states, Int32 exitDestination)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.AddNode(DfaNode node, DfaState[] states, Int32 exitDestination)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.AddNode(DfaNode node, DfaState[] states, Int32 exitDestination)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.AddNode(DfaNode node, DfaState[] states, Int32 exitDestination)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherBuilder.Build()
at Microsoft.AspNetCore.Routing.Matching.DataSourceDependentMatcher.CreateMatcher(IReadOnlyList`1 endpoints)
at Microsoft.AspNetCore.Routing.DataSourceDependentCache`1.Initialize()
at System.Threading.LazyInitializer.EnsureInitializedCore[T](T& target, Boolean& initialized, Object& syncLock, Func`1 valueFactory)
at System.Threading.LazyInitializer.EnsureInitialized[T](T& target, Boolean& initialized, Object& syncLock, Func`1 valueFactory)
at Microsoft.AspNetCore.Routing.Matching.DataSourceDependentMatcher..ctor(EndpointDataSource dataSource, Lifetime lifetime, Func`1 matcherBuilderFactory)
at Microsoft.AspNetCore.Routing.Matching.DfaMatcherFactory.CreateMatcher(EndpointDataSource dataSource)
at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.InitializeCoreAsync()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.<Invoke>g__AwaitMatcher|8_0(EndpointRoutingMiddleware middleware, HttpContext httpContext, Task`1 matcherTask)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
編輯:有我的依賴項。 當我刪除這些然后它工作。
<PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="3.0.0" />
<PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="3.1.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.1.0">
<PrivateAssets>all</PrivateAssets>
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
</PackageReference>
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.1.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0">
<PrivateAssets>all</PrivateAssets>
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
</PackageReference>
<PackageReference Include="Microsoft.Extensions.Caching.SqlServer" Version="3.1.0" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="3.0.0" />
<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.0.0" />
<PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="5.0.0-rc4" />
<PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.0.0-rc4" />
<PackageReference Include="Z.EntityFramework.Plus.EFCore" Version="3.0.24" />
<PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
<PackageReference Include="Swashbuckle.AspNetCore" Version="5.0.0-rc4" />
如果你使用類似的東西
[HttpGet("example/{param1:string}/{param2:Guid}")]
將其更改為
[HttpGet("example/{param1}/{param2:Guid}")]
因為 ":string" 實際上被解釋為regex-validation-constraint而不是類型定義,猜猜看,一切都以字符串形式到達服務器,並且沒有 string-regex-validator :)
它可以是參數名稱和類型之間的空格。
例子:
{param1 :alpha} 🚫
{param1:alpha} ✅
在我的情況下,它只是路由參數和數據類型({id:int})之間的一個空格
啊,我的問題是變量命名不匹配。
不工作
[HttpGet("{id}")]
public async Task<ActionResult<UserDto>> Get(string userId) {
//some code
}
“userId”應更改為“id”
在職的
[HttpGet("{id}")]
public async Task<ActionResult<UserDto>> Get(string id) {
//some code
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.