private static TView ContractToViewAdapterImpl <TView>(ContractHandle contract, String pipelineRoot, bool demand)
{
if (contract == null)
{
throw new ArgumentNullException("contract");
}
if (pipelineRoot == null)
{
throw new ArgumentNullException("pipelineRoot");
}
if (String.IsNullOrEmpty(pipelineRoot))
{
throw new ArgumentException(Res.PathCantBeEmpty);
}
System.Diagnostics.Contracts.Contract.EndContractBlock();
if (demand)
{
new FileIOPermission(FileIOPermissionAccess.Read, pipelineRoot).Demand();
}
Type havType = typeof(TView);
TypeInfo havTypeInfo = new TypeInfo(havType);
List <PartialToken> partialTokens = AddInStore.GetPartialTokens(pipelineRoot);
foreach (PartialToken partialToken in partialTokens)
{
if (AddInStore.Contains(partialToken.HostAdapter.HostAddinViews, havTypeInfo))
{
partialToken.PipelineRootDirectory = pipelineRoot;
//Ask for something that can implement the contract in this partial token. The result will
//either be null, the addin adapter itself, or another addin adapter
IContract subcontract = contract.Contract.QueryContract(partialToken._contract.TypeInfo.AssemblyQualifiedName);
if (subcontract != null)
{
//Instantiate the adapter and pass in the addin to its constructor
TView hav = AddInActivator.ActivateHostAdapter <TView>(partialToken, subcontract);
return(hav);
}
}
}
// Don't let the ref count go to zero too soon, before we increment it in ActivateHostAdapter
// This is important when QueryContract returns the addIn adapter itself. A GC at that point
// may collect the ContractHandle and decrement the ref count to zero before we have a chance to increment it
System.GC.KeepAlive(contract);
// return null. Compiler makes us return default(TView), which will be null
return(default(TView));
}