小编Mon*_*use的帖子

当我添加 sql 数据库时，我在 Startup.cs 中收到一个错误，我不知所措。我输入：

 services.AddDbContext<ModelContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DatabaseConnection")));

好吧，我实际上是从 program.cs 中得到的，但错误源自上面的行。呼叫者：

var context = services.GetRequiredService<ModelContext>();

错误信息是：

Method 'Clone' 
in type 'Microsoft.EntityFrameworkCore.Infrastructure.Internal.SqlServerOptionsExtension' 
from assembly 'Microsoft.EntityFrameworkCore.SqlServer, Version=1.1.5.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.

错误来源是：

Microsoft.EntityFrameworkCore.SqlServer

完整的错误信息：

+       Data    {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
        HResult -2146233054 int
        HelpLink    null    string
+       InnerException  null    System.Exception
        Message "Method 'Clone' in type 'Microsoft.EntityFrameworkCore.Infrastructure.Internal.SqlServerOptionsExtension' from assembly 'Microsoft.EntityFrameworkCore.SqlServer, Version=1.1.5.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation."  string
        Source  "Microsoft.EntityFrameworkCore.SqlServer"   string
        StackTrace  "   at Microsoft.EntityFrameworkCore.SqlServerDbContextOptionsExtensions.UseSqlServer\r\n   at FltCandidates.Startup.<ConfigureServices>b__4_0(DbContextOptionsBuilder options) in C:\\Users\\garry\\source\\repos\\FltCandidates\\FltCandidates\\Startup.cs:line …