我正在尝试构建基于Web的GUI来使用基于LOB Adapter SDK的自定义连接器。 特别是,我想使用IMetadataResolverHandler界面浏览元数据。
我有两个问题:
尝试实例化自定义适配器时会出现第一个问题。我的计划是获取IConnectionFactory接口的实例,通过该接口,我可以获得一个新的IConnection并连接到目标LOB系统。
由于Adapter基类中最有趣的方法受到保护,我似乎只能使用反射成功(请参阅下面的示例代码)。
尝试从目标系统浏览元数据时发生第二个问题。 IMetadataResolverHandler接口上的方法Browse
需要一个MetadataLookup对象的实例,我不知道如何获取。
请参阅下面的示例代码:
static void Main(string[] args)
{
var extension = new SqlAdapterBindingElementExtensionElement();
var adapter = (Adapter) Activator.CreateInstance(extension.BindingElementType);
var isHandlerSupportedMethodInfo = adapter.GetType().GetMethod("IsHandlerSupported", BindingFlags.NonPublic | BindingFlags.Instance);
var buildConnectionUri = adapter.GetType().GetMethod("BuildConnectionUri", BindingFlags.NonPublic | BindingFlags.Instance);
var buildConnectionFactory = adapter.GetType().GetMethod("BuildConnectionFactory", BindingFlags.NonPublic | BindingFlags.Instance);
if (isHandlerSupportedMethodInfo == null || buildConnectionUri == null || buildConnectionFactory == null)
{
Console.WriteLine("Not a LOB adapter.");
Environment.Exit(1);
}
var isHandlerSupportedTHandler = isHandlerSupportedMethodInfo.MakeGenericMethod(typeof(IMetadataResolverHandler));
var isMetadataBrowseSupported = (bool)isHandlerSupportedTHandler.Invoke(adapter, new object[] { });
if (!isMetadataBrowseSupported)
{
Console.WriteLine("Metadata retrieval not supported.");
Environment.Exit(1);
}
var bindingElement = (SqlAdapterBindingElement)adapter;
bindingElement.AcceptCredentialsInUri = false;
bindingElement.InboundOperationType = InboundOperation.TypedPolling;
bindingElement.PolledDataAvailableStatement = "EXEC [dbo].[usp_IsDataAvailable]";
bindingElement.PollingStatement = "EXEC [dbo].[usp_SelectAvailableData]";
bindingElement.PollingIntervalInSeconds = 10;
var binding = new CustomBinding();
binding.Elements.Add(adapter);
var parameters = new BindingParameterCollection();
var context = new BindingContext(binding, parameters);
var credentials = new ClientCredentials();
credentials.UserName.UserName = "username";
credentials.UserName.Password = "password";
var address = (ConnectionUri) buildConnectionUri.Invoke(adapter, new []{ new Uri("mssql://azure.database.windows.net//SampleDb?InboundId=uniqueId")});
var connectionFactory = (IConnectionFactory)buildConnectionFactory.Invoke(adapter, new object[] { address, credentials, context });
var connection = connectionFactory.CreateConnection();
connection.Open(TimeSpan.MaxValue);
MetadataLookup lookup = null; // ??
var browser = connection.BuildHandler<IMetadataBrowseHandler>(lookup);
connection.Close(TimeSpan.MaxValue);
}
答案 0 :(得分:1)
回答我自己的问题,我通过检查“消费适配器服务”向导的代码来解决这个问题。关键是使用IMetadataRetrievalContract
接口,在内部使用最多三个LOB-SDK接口实现,特别是IMetadataResolverHandler
。
以下是无反射的代码:
var extension = new SqlAdapterBindingElementExtensionElement();
var adapter = (Adapter) Activator.CreateInstance(extension.BindingElementType);
var bindingElement = (SqlAdapterBindingElement)adapter;
bindingElement.AcceptCredentialsInUri = false;
bindingElement.InboundOperationType = InboundOperation.TypedPolling;
bindingElement.PolledDataAvailableStatement = "EXEC [dbo].[usp_IsDataAvailable]";
bindingElement.PollingStatement = "EXEC [dbo].[usp_SelectAvailableData]";
bindingElement.PollingIntervalInSeconds = 10;
var binding = new CustomBinding();
binding.Elements.Add(adapter);
const string endpoint = "mssql://azure.database.windows.net//SampleDb?InboundId=unique";
var factory = new ChannelFactory<IMetadataRetrievalContract>(binding, new EndpointAddress(new Uri(endpoint)));
factory.Credentials.UserName.UserName = "username";
factory.Credentials.UserName.Password = "password";
factory.Open();
var channel = factory.CreateChannel();
((IChannel)channel).Open();
var metadata = channel.Browse(MetadataRetrievalNode.Root.DisplayName, 0, Int32.MaxValue);
((IChannel) channel).Close();
factory.Close();