c# - Remove part of Expression -

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i have generic method:

public void expressionbuilder<t>() t: ientity {    expression<func<t, long>> expr = e => e.id; //id part of ientity    ... }

the resulted expression contains casting of t ientity: e => convert(e).id want remove casting (to make possible ef generate sql). in other words replace convert(e) e.

if assume public long id {get;} on t, , expression simple, maybe build manually:

var param = expression.parameter(typeof (t), "e"); var lambda = expression.lambda<func<t, long>>(           expression.propertyorfield(param,"id"), param);

a visitor should work more complex examples; example:

internal class flatteninterface<t> : expressionvisitor {     protected override expression visitmember(memberexpression node)     {         if(node.member.declaringtype == typeof(t))         {             return expression.makememberaccess(                 node.expression,                 node.expression.type.getmember(node.member.name).single());         }         return base.visitmember(node);     } }

and

var direct = (expression<func<t, long>>)new flatteninterface<ientity>()        .visit(expr);

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