public static LambdaExpression CreateNewExpr(ParameterExpression Pr, Dictionary <string, string> Dict, object ParamsObject)
{
ParamsObject = ParamsObject ?? new { };
var dict = new Dictionary <string, Type>();
var argsDict = new Dictionary <string, Expression>();
foreach (var x in Dict)
{
var FX = x.Value.FixBracket().FixSpace().ToFxExpression();
var fx = ExprBuilders.ToExpression(Pr, FX, ParamsObject);
argsDict.Add(x.Key, fx);
dict.Add(x.Key, fx.Type);
}
var t = CreateNewType(dict);
var args = new List <Expression>();
var outputParam = Expression.Parameter(t, "n");
var mbxs = new List <MemberInfo>();
foreach (var x in argsDict)
{
//var mx = Expression.MakeMemberAccess(outputParam, t.GetProperty(x.Key));
//var ax = Expression.Assign(mx, x.Value);
args.Add(x.Value);
mbxs.Add(t.GetProperty(x.Key));
}
var nx = Expression.New(t.GetConstructors()[0],
args.ToArray(),
mbxs.ToArray()
);
return(Expression.Lambda(nx, Pr));
}
public static void Test20210205()
{
Expression <Func <MyClass, object> > px = p => new {
MyCode = p.Code
};
var dict = new Dictionary <string, string>();
dict.Add("MyCode", "Code");
dict.Add("MyName", "Name");
var Pr = Expression.Parameter(typeof(MyClass), "p");
Expression <Func <MyClass, dynamic> > LD = ExprBuilders.CreateSelector <MyClass>("Code MyCode,Name MyName", new { });
var lst = new List <MyClass>();
lst.Add(new MyClass
{
Code = "123"
});
lst.Add(new MyClass
{
Code = "1234"
});
var ret = lst.Select(LD.Compile()).ToList();
foreach (var x in ret)
{
Console.WriteLine(x.MyCode);
}
}