flutter 发生异常：CLR/System.AggregateException

我试着调试我从教程中得到的代码，但我在构建中得到了这个错误。我正在使用.Net 6

An unhandled exception of type 'System.AggregateException' occurred in Microsoft.Extensions.DependencyInjection.dll: 'Some services are not able to be constructed'
 Inner exceptions found, see $exception in variables window for more details.
 Innermost exception     System.InvalidOperationException : Unable to activate type 'fixit.Data.DataContext'. The following constructors are ambiguous:
Void .ctor(Microsoft.Extensions.Configuration.IConfiguration)
Void .ctor(Microsoft.EntityFrameworkCore.DbContextOptions`1[fixit.Data.DataContext])

这是我的程序. cs我改变了很多，因为它很难重写从startup.cs.net5没有得到一个错误

using fixit.Data;
using fixit.Models;
using Microsoft.Data.SqlClient;
using Microsoft.EntityFrameworkCore;
using Pomelo.EntityFrameworkCore.MySql;

var builder = WebApplication.CreateBuilder(args);


// Add services to the container

builder.Services.AddDbContext<DataContext>(opt => opt.UseMySql(builder.Configuration.GetConnectionString("WebApiDatabase"), 
ServerVersion.AutoDetect(builder.Configuration.GetConnectionString("WebApiDatabase"))));
builder.Services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());
builder.Services.AddCors(option =>
            {
                option.AddPolicy("allowedOrigin",
                    builder => builder.AllowAnyOrigin().AllowAnyMethod().AllowAnyHeader()
                    );
            });
builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddScoped<IRepository<Service>, ServiceRepository>();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
}

app.UseCors(builder => builder
       .AllowAnyHeader()
       .AllowAnyMethod()
       .AllowAnyOrigin()
    );
app.UseHttpsRedirection();

app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();

app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
});

app.Run();

i在行 var app = builder.Build（）中获得错误异常; .这是我的datacontext.cs，因为它似乎是错误来自这里。

using fixit.Models;
using Microsoft.EntityFrameworkCore;

namespace fixit.Data

{
    
    public class DataContext : DbContext
    {
        protected readonly IConfiguration Configuration;

    public DataContext(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
    {
        // connect to mysql with connection string from app settings
        var connectionString = Configuration.GetConnectionString("WebApiDatabase");
        options.UseMySql(connectionString, ServerVersion.AutoDetect(connectionString));
    }
        public DataContext() { }
        public DataContext(DbContextOptions<DataContext> options) : base(options) { }

            public DbSet<Service> Service { get; set; }
        
        }
}

如何解决这个问题？我尝试使用API控制器将Flutter与Web-API和IM集成在一起，

这个问题的原因是使用DataContext构造函数两次，然后我们得到错误消息The following constructors are ambiguous。

解决方案

像下面这样修改你的代码，问题就解决了。

using fixit.Models;
using Microsoft.EntityFrameworkCore;
using System.Web.Services.Description;

namespace fixit.Data
{
    public class DataContext : DbContext
    {
        protected readonly IConfiguration Configuration;

        public DataContext() { }
        public DataContext(DbContextOptions<DataContext> options, IConfiguration configuration) : base(options) {
            Configuration = configuration;
        }

        protected override void OnConfiguring(DbContextOptionsBuilder options)
        {
            // connect to mysql with connection string from app settings
            var connectionString = Configuration.GetConnectionString("WebApiDatabase");
            options.UseMySql(connectionString, ServerVersion.AutoDetect(connectionString));
        }
        public DbSet<Service> Service { get; set; }

    }
}

flutter 发生异常：CLR/System.AggregateException

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