50-Identity MVC：DbContextSeed初始化

1-创建一个可以启动时如果没有一个账号刚创建1个新的账号

namespace MvcCookieAuthSample.Data
{
    public class ApplicationDbContextSeed
    {
        public async Task SeedAsync(ApplicationDbContext context, IServiceProvider service)
        {
            if (!context.Users.Any())
            {
                var _userManager= service.GetRequiredService<UserManager<ApplicationUser>>();
                var user = new ApplicationUser() {
                     Email="qinzhb@163.com",
                     UserName="qinzhb",
                     NormalizedUserName="qinzhb"
                };

                var result = await _userManager.CreateAsync(user, "123456@Byd");
                if (!result.Succeeded)
                {
                    throw new Exception("初始化用户失败");
                }

            }
        }
    }
}

2-增加一个扩展方法，用于启动时初始化数据库

namespace MvcCookieAuthSample
{
    public static class WebHostMigrationExtensions
    {
        public static IWebHost MigrationDbContext<TContext>(this IWebHost host,Action<TContext ,IServiceProvider> seeder)
            where TContext:DbContext
        {
            using (var scope = host.Services.CreateScope())
            {
                var service = scope.ServiceProvider;
                var logger = service.GetRequiredService<ILogger<TContext>>();
                var context =  service.GetService<TContext>();

                try
                {
                    context.Database.Migrate();
                    seeder(context, service);
                    logger.LogInformation("执行方法数据库初始化成功");

                }
                catch
                {
                    logger.LogError("执行数据库数据库初始化密码失败");
                }

            }
            
            return host;
        }
    }
}

3-把上面的2方法增加到启动类中

  public static void Main(string[] args)
        {
            CreateWebHostBuilder(args)
                
                .Build()
                .MigrationDbContext<ApplicationDbContext>((context,services)=> {
                    new Data.ApplicationDbContextSeed().SeedAsync(context, services).Wait();
                }).Run();
        }