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POCall Func<> with argument of type object
 

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    <p>I have (for instance) a <code>Func&lt;int, int&gt;</code> which I want to call as usual, except that the parameter is of type <code>object</code> rater than <code>int</code>. I only know the exact type of the Func and the argument at runtime, because the Func was created using Expression trees and is now accessed from a <code>dynamic</code> variable. (Simplified) code example:</p> <pre><code>using System.Linq.Expressions; namespace FuncExample { class Program { static void Main(string[] args) { object myFunc = CreateFunc(); // Could return something like // Func&lt;int, int&gt;, but may return a // completely different Func&lt;&gt; depending on // arguments etc. object result = getFromFunc(5, myFunc); } public static object CreateFunc() { LambdaExpression expr = Expression.Lambda( /* * Create an expression */ ); return expr.Compile(); } public static object getFromFunc(object arg, object func) { dynamic dynFunc = func; return dynFunc(arg); // &lt;------- Throws exception } } } </code></pre> <p>How can I make the code convert <code>arg</code> into an integer or whatever Type the argument is? I tried making a generic method that casts the object to a certain type and then invoking it through reflection like this:</p> <pre><code>public static T asT&lt;T&gt;(object n) { return (T)n; } </code></pre> <p>for <code>getFromFunc</code>:</p> <pre><code>MethodInfo con = typeof(Program).GetMethod("asT").MakeGenericMethod(func.GetType().GetGenericArguments()[0]); return dfunc(con.Invoke(null, new[] { value })); </code></pre> <p>But <code>MethodInfo.Invoke</code> also returns <code>object</code>. Any ideas on how to make sure the argument has the correct type?</p>
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    1. USMarkus Himmel
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    1. COwhat exception does it throw?
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      1. USCharles Lambert
    2. CO@CharlesLambert On my system, I get "Delegate 'System.Func<int,int>' has some invalid arguments". It uses `arg`'s static type, `object`, which is inappropriate for a function with a parameter of type `int`.
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