[英]The constraint reference 'string' could not be resolved to a type. (netcoreapp3.0)
I have got an error.我有一个错误。 This is my Startup class.
这是我的启动课。
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
}
public void Configure(IApplicationBuilder app)
{
app.UseDeveloperExceptionPage();
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
Current technology "netcoreapp3.0" and my controller is.当前技术“netcoreapp3.0”和我的控制器是。
[Route("api/[controller]")]
[ApiController]
public class ExampleController : ControllerBase
{
[HttpGet("request")]
public ActionResult Index()
{
return Ok();
}
}
And here is my error.这是我的错误。 I couldn't find a solution, I even didn't get what exactly this is.
我找不到解决方案,我什至不知道这到底是什么。 So here we are.
所以我们在这里。
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)
EDIT: There is my dependencies.编辑:有我的依赖项。 When I remove these then it worked.
当我删除这些然后它工作。
<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" />
In case you use something like如果你使用类似的东西
[HttpGet("example/{param1:string}/{param2:Guid}")]
change it to将其更改为
[HttpGet("example/{param1}/{param2:Guid}")]
because ":string" is actually interpreted as a regex-validation-constraint and not a type definition and guess what, everything is reaching the server as string and there is no string-regex-validator :)因为 ":string" 实际上被解释为regex-validation-constraint而不是类型定义,猜猜看,一切都以字符串形式到达服务器,并且没有 string-regex-validator :)
I also encountered this recently.我最近也遇到了这种情况。 The fix for me as to use "alpha" as a replacement for the string type:
对我来说使用“alpha”作为字符串类型的替代品的修复:
[HttpGet("example/{param1:alpha}")]
This was documented in the Microsoft documentation .这已记录在Microsoft 文档中。
It could be a blank space between the param name and the type.它可以是参数名称和类型之间的空格。
Example:例子:
{param1 :alpha} 🚫 {param1 :alpha} 🚫
{param1:alpha} ✅ {param1:alpha} ✅
在我的情况下,它只是路由参数和数据类型({id:int})之间的一个空格
Ahh, my issue was variable naming mismatch.啊,我的问题是变量命名不匹配。
Not Working不工作
[HttpGet("{id}")]
public async Task<ActionResult<UserDto>> Get(string userId) {
//some code
}
"userId" should change to "id" “userId”应更改为“id”
Working在职的
[HttpGet("{id}")]
public async Task<ActionResult<UserDto>> Get(string id) {
//some code
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.