/// <summary>
/// Cria a expressão de acesso ao indexador.
/// </summary>
/// <param name="instance"></param>
/// <param name="indexerToken"></param>
/// <returns></returns>
private Expression CreateIndexerAccessExpression(Expression instance, IndexerToken indexerToken)
{
return(Expression.Dynamic(Microsoft.CSharp.RuntimeBinder.Binder.GetIndex(Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags.None, typeof(DynamicPropertyAccessExpressionBuilder), new[] {
Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo.Create(Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags.None, null),
Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo.Create(Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags.Constant | Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags.UseCompileTimeType, null)
}), typeof(object), new Expression[] {
instance,
indexerToken.Arguments.Select <object, ConstantExpression>(new Func <object, ConstantExpression>(Expression.Constant)).First <ConstantExpression>()
}));
}
/// <summary>
/// Recupera as informações do membro a partir do token do indexador.
/// </summary>
/// <param name="token"></param>
/// <param name="targetType"></param>
/// <returns></returns>
private static MemberInfo GetMemberInfoFromIndexerToken(IndexerToken token, Type targetType)
{
PropertyInfo indexerPropertyInfo = targetType.GetIndexerPropertyInfo((from a in token.Arguments
select a.GetType()).ToArray <Type>());
if (indexerPropertyInfo != null)
{
return(indexerPropertyInfo.GetGetMethod());
}
return(null);
}
/// <summary>
/// Tenta executar o parse para o token do indexador.
/// </summary>
/// <param name="member"></param>
/// <param name="token"></param>
/// <returns></returns>
private static bool TryParseIndexerToken(string member, out IndexerToken token)
{
token = null;
if (!IsValidIndexer(member))
{
return(false);
}
List <object> arguments = new List <object>();
arguments.AddRange(from a in ExtractIndexerArguments(member)
select ConvertIndexerArgument(a));
token = new IndexerToken(arguments);
return(true);
}
/// <summary>
/// Cria a expressão de acesso para o membro.
/// </summary>
/// <param name="token"></param>
/// <param name="instance"></param>
/// <returns></returns>
public static Expression CreateMemberAccessExpression(this IMemberAccessToken token, Expression instance)
{
System.Reflection.MemberInfo memberInfoForType = token.GetMemberInfoForType(instance.Type);
if (memberInfoForType == null)
{
throw new ArgumentException(FormatInvalidTokenErrorMessage(token, instance.Type));
}
IndexerToken indexerToken = token as IndexerToken;
if (indexerToken != null)
{
IEnumerable <Expression> indexerArguments = indexerToken.GetIndexerArguments();
return(Expression.Call(instance, (System.Reflection.MethodInfo)memberInfoForType, indexerArguments));
}
return(Expression.MakeMemberAccess(instance, memberInfoForType));
}
/// <summary>
/// Recupera as informações do membro para o tipo informado.
/// </summary>
/// <param name="token"></param>
/// <param name="targetType"></param>
/// <returns></returns>
private static MemberInfo GetMemberInfoForType(this IMemberAccessToken token, Type targetType)
{
PropertyToken token2 = token as PropertyToken;
if (token2 != null)
{
return(GetMemberInfoFromPropertyToken(token2, targetType));
}
IndexerToken token3 = token as IndexerToken;
if (token3 == null)
{
throw new InvalidOperationException(token.GetType().GetTypeName() + " is not supported");
}
return(GetMemberInfoFromIndexerToken(token3, targetType));
}
/// <summary>
///
/// </summary>
/// <param name="indexerToken"></param>
/// <returns></returns>
private static IEnumerable <Expression> GetIndexerArguments(this IndexerToken indexerToken)
{
return(from a in indexerToken.Arguments
select Expression.Constant(a));
}
