首先，确保已经正确安装了AutoMapper包。然后，在Startup.cs文件中添加以下代码：

在ConfigureServices方法中：

services.AddAutoMapper(typeof(Startup));

在Configure方法中：

app.UseAutoMapper();

这将启用AutoMapper并将其配置为在应用程序中自动映射。确保在使用AutoMapper之前已注入服务，并确保在使用AutoMapper之前引用它的名称空间。

以下是完整的Startup.cs示例代码：

using AutoMapper; using Microsoft.AspNetCore.Builder; using Microsoft.AspNetCore.Hosting; using Microsoft.Extensions.Configuration; using Microsoft.Extensions.DependencyInjection; using Microsoft.Extensions.Hosting;

namespace YourNamespace { public class Startup { public Startup(IConfiguration configuration) { Configuration = configuration; }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers();

        services.AddAutoMapper(typeof(Startup));
    }

    // 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.UseHttpsRedirection();

        app.UseRouting();

        app.UseAuthorization();

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

        app.UseAutoMapper();
    }
}

}