c# - ObjectContext 的 SetTransactionHandler

Question

如何为 ObjectContext 设置 TransactionHandler？

我正在检查这个例子:Handling of Transaction Commit Failures ，但仅针对 DbContext 显示。

Answer 1

TransactionHandler 也适用于 ObjectContext。唯一的问题是，在实例化第一个 DbContext 之前，不会评估基于代码的配置 (DbConfiguration)。

两种可能的解决方法

虚拟 DbContext:

public class MyDbConfiguration : DbConfiguration
{
    public MyDbConfiguration()
    {
        SetTransactionHandler(SqlProviderServices.ProviderInvariantName, 
            () => new CommitFailureHandler());
    }
}

public class TestContext : DbContext { }

static void Main(string[] args)
{
    // instantiate DbContext to initialize code based configuration
    using (var db = new TestContext()) { }

    using (var db = new TransactionHandlerDemoEntities()) {
        var handler = db.TransactionHandler; // should be CommitFailureHandler

        db.AddToDemoTable(new DemoTable { Name = "TestEntiry1" });
        db.SaveChanges();
    }
}

或者DbConfiguration.Loaded事件

static void Main(string[] args)
{
    DbConfiguration.Loaded += DbConfiguration_Loaded;

    using (var db = new TransactionHandlerDemoEntities()) {
        var handler = db.TransactionHandler;

        db.AddToDemoTable(new DemoTable { Name = "TestEntiry1" });
        db.SaveChanges();
    }
}

static void DbConfiguration_Loaded(object sender, DbConfigurationLoadedEventArgs e)
{
    e.AddDependencyResolver(new TransactionHandlerResolver(
        () => new CommitFailureHandler(),
        SqlProviderServices.ProviderInvariantName,
        null),true);
}

TransactionHandlerDemoEntities 是一个 ObjectContext。