public static MemberExpression ReplaceParameter(this ParameterExpression param, MemberExpression expr)
{
var path = expr.ToString();
var index = path.IndexOf('.');
path = path.Substring(index + 1);
return(param.CreateMemberExpresion(path));
}
public static LambdaExpression CreateLambdaExpresion(this ParameterExpression param, IList <MemberExpression> list)
{
var type = param.Type.CreateDynamicType(list);
var memberExprList = new List <MemberAssignment>();
foreach (var expr in list)
{
var str = expr.ToString();
str = str.Substring(str.IndexOf('.') + 1);
var info = type.GetProperty(str);
var memberExpr = param.CreateMemberExpresion(str);
memberExprList.Add(Expression.Bind(info, memberExpr));
}
var memberInit = Expression.MemberInit(Expression.New(type), memberExprList);
return(Expression.Lambda(memberInit, param));
}