使用Arcengine开发的程序连接sql server Express失败

 // For example, for direct connect with OSA authentication. 

// DBConnProp = tivo_sqlexpress. 

// Instance = sde:sqlserver:tivo\\sqlexpress. 

// Database = sewer. 

// Authentication_mode = OSA. 

// Version = dbo.DEFAULT. 

public static IWorkspace WorkgroupArcSdeWorkspaceFromPropertySet(String server, String instance, 

String authenticationMode, String database, String version) 

{ 

IPropertySet propertySet = new PropertySetClass();  propertySet.SetProperty（“INSTANCE'',Instance = sde:sqlserver:tivo\\sqlexpress.)

propertySet.SetProperty(DB_CONNECTION_PROPERTIES, DBConnProp); 

propertySet.SetProperty(DATABASE, database); 

propertySet.SetProperty(AUTHENTICATION_MODE, authenticationMode); 

propertySet.SetProperty(VERSION, version); 



Type factoryType = Type.GetTypeFromProgID(esriDataSourcesGDB.SdeWorkspaceFactory); 

IWorkspaceFactory workspaceFactory = (IWorkspaceFactory)Activator.CreateInstance(factoryType); 

return workspaceFactory.Open(propertySet, 0); 

}