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    <p>You can do this by using an open generic type definition, and then making the specific type from that:</p> <pre><code>typeof(Func&lt;,&gt;).MakeGenericType(typeof(int), orderType); </code></pre> <p>However, what you're trying to do (calling <code>Lambda&lt;TDelegate&gt;</code>) is not directly possible. You must call <code>Lambda</code> without a type parameter:</p> <pre><code>var propertyinfo = typeof(T).GetProperty(sortExpressionStr); Type orderType = propertyinfo.PropertyType; var param = Expression.Parameter(typeof(T), "x"); var sortExpression = Expression.Lambda( Expression.Convert(Expression.Property(param, sortExpressionStr), orderType), param)); </code></pre> <p>This will create the proper <code>Func&lt;,&gt;</code> for you behind the scenes. If you want to compile the expression and use the delegate, you can only do this dynamically with</p> <pre><code>sortExpression.Compile().DynamicInvoke(param); </code></pre> <p>If you want to call the <code>OrderBy</code> extension method on <code>Queryable</code>, things get a little more complicated:</p> <pre><code>var propertyInfo = typeof(T).GetProperty(sortExpressionStr); Type orderType = propertyInfo.PropertyType; // first find the OrderBy method with no types specified MethodInfo method = typeof(Queryable).GetMethods() .Where(m =&gt; m.Name == "OrderBy" &amp;&amp; m.GetParameters().Length == 2) .Single(); // then make the right version by supplying the right types MethodInfo concreteMethod = method.MakeGenericMethod(typeof(T), orderType); var param = Expression.Parameter(typeof(T), "x"); // the key selector for the OrderBy method Expression orderBy = Expression.Lambda( Expression.Property(orderParam, propertyInfo), orderParam); // how to use: var sequence = new T[0].AsQueryable(); // sample IQueryable // because no types are known in advance, we need to call Invoke // through relection here IQueryable result = (IQueryable) concreteMethod.Invoke( null, // = static new object[] { sequence, orderBy }); </code></pre>
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    1. PODeclaring Func<in T, out Result> dynamically
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    1. USRuben
    1. USRuben
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    1. COno buddy , typeof(orderType) wouldnt compile , i tried that already
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    2. COtypeof(orderType) is not logical , since your trying to typeof is in compile time and ordertype only in runtime i guess
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    3. COSorry, `typeof(orderType)` was a copy-paste error. Fixed.
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