添加迁移时,我在package manager控制台中出现以下错误
值不能为空.参数名称:connectionString
这是我的创业公司:
namespace MyProject
{
public class Startup
{
public IConfiguration Configuration { get; set; }
public Startup(IConfiguration config)
{
Configuration = config;
}
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContextPool<AppDbContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
services.AddTransient<IDevRepo, DevRepo>();
services.AddMvc();
services.AddMemoryCache();
services.AddSession();
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseStatusCodePages();
app.UseStaticFiles();
app.UseMvcWithDefaultRoute();
app.Run(async (context) =>
{
await context.Response.WriteAsync(Configuration["Message"]);
});
}
}
}
课程类别:
public class Program
{
public static void Main(string[] args)
{
BuildWebHost(args).Run();
}
public static IWebHost BuildWebHost(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.ConfigureAppConfiguration((context, builder) => builder.SetBasePath(context.HostingEnvironment.ContentRootPath)
.AddJsonFile("appsettings.json")
.Build())
.UseStartup<Startup>()
.Build();
}
应用设置.json:
{
"Message": "Hello World",
"ConnectionStrings": {
"DefaultConnection": "Server=(localdb)\\MSSQLLocalDB;Database=NotMyFault;Trusted_Connection=True;MultipleActiveResultSets=true"
}
}
有趣的是,如果我运行这个应用程序,它会显示"Hello World",但是当添加迁移时,它找不到connectionString.有没有人能在这里开几盏灯?谢谢.