C# Net核心：使用变量类型声明新的DbContext

如何声明DbContextOptionsBuilder，其中DbContext存储在一个变量中（在本例中，DbContext的真实名称是“OnlineShoppingStore”，但存储在下面的两个变量中）

var dbContextType = dbContextAssembly.GetTypes().Where(d => d.BaseType.Name == "DbContext").First();
var businessDbContext = Activator.CreateInstance(dbContextType) as DbContext;
DbContextOptionsBuilder optionsBuilder = new DbContextOptionsBuilder();

// Attempting Line Below
var options = new DbContextOptionsBuilder<dbContextType>().UseInMemoryDatabase(databaseName: "Test").Options;

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就快到了。您可以使用以下方法创建泛型类型的实例：

Type dbContextType = typeof(MyDbContext);
// 1st get type of Generic object
Type dbContextOptionsBuilderType = typeof(DbContextOptionsBuilder<>);
// 2nd call "MakeGenericType" method by passing the "T" type
Type dbContextOptionsBuilderGenericType = dbContextOptionsBuilderType.MakeGenericType(dbContextType);
// 3rd create an instance by using "Activator.CreateInstance"
DbContextOptionsBuilder dbContextOptionsBuilderInstance = Activator.CreateInstance(dbContextOptionsBuilderGenericType) as DbContextOptionsBuilder;

DbContextOptions dbContextOptions = dbContextOptionsBuilderInstance.UseInMemoryDatabase(databaseName: "Test").Options;

Type-dbContextType=typeof（MyDbContext）；
//第一个获取泛型对象的类型
类型dbContextOptionsBuilderType=typeof（DbContextOptionsBuilder）；
//通过传递“T”类型第二次调用“MakeGenericType”方法
键入DbContextOptions BuilderGenericType=DbContextOptions BuilderType.MakeGenericType（dbContextType）；
//第三，使用“Activator.CreateInstance”创建实例
DbContextOptionsBuilderDbContextOptionsBuilderInstance=Activator.CreateInstance（dbContextOptionsBuilderGenericType）作为DbContextOptionsBuilder；
DbContextOptions DbContextOptions=DbContextOptions BuilderInstance.UseInMemoryDatabase（databaseName:“Test”）.Options；

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“”是原始解决方案。

您可以使用非通用版本的

DbContextOptionsBuilder

吗？如何操作？您可以将其链接到汇编语句吗？我正在尝试在我的一个程序集上运行第一条语句dbContextType，不工作，相同的错误类型test=typeof（dbContextType）同时尝试运行最后一条语句new businessDbContext（dbContextOptions）需要实例化dbContext，并使用其选项尝试此操作，对我来说效果很好Assembly dbContextAssembly=Assembly.GetExecutionGassembly（）；var dbContextType=dbContextAssembly.GetTypes（）。其中（p=>p.BaseType.Name==“DbContext”）.First（）；

Type dbContextType = typeof(MyDbContext);
// 1st get type of Generic object
Type dbContextOptionsBuilderType = typeof(DbContextOptionsBuilder<>);
// 2nd call "MakeGenericType" method by passing the "T" type
Type dbContextOptionsBuilderGenericType = dbContextOptionsBuilderType.MakeGenericType(dbContextType);
// 3rd create an instance by using "Activator.CreateInstance"
DbContextOptionsBuilder dbContextOptionsBuilderInstance = Activator.CreateInstance(dbContextOptionsBuilderGenericType) as DbContextOptionsBuilder;

DbContextOptions dbContextOptions = dbContextOptionsBuilderInstance.UseInMemoryDatabase(databaseName: "Test").Options;