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POCan I pass an object by reference
 

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    <p>I am trying to pass an object from an xna game into a method in an xna game library I'm writing. The object could be basically any type, both reference and value types.</p> <p>The game library is for debug purposes and should print out to the screen the current value of the object passed in. It currently does this by calling <code>ToString</code> on the object but in the future the string will be formatted depending on the underlying type.</p> <p>Here is the game library method that receives the argument</p> <pre><code> public void AddToDebug(object obj) { var type = obj.GetType(); _debugTypes.Add(obj, type); } </code></pre> <p>And here is an example of using it from within the main game project</p> <pre><code>VD.AddToDebug(_counter); VD.AddToDebug(_message); </code></pre> <p><code>_counter</code> is an int and <code>_message</code> is a string.</p> <p>The issue is that changes in these values are not reflected on screen because (I assume) they are passed by value and not by reference.</p> <p>I tried adding the ref keyword to ensure they are passed by reference but that causes an error in the method calls <code>The ref argument type does not match parameter type</code></p> <p>Is there a way I can pass value types by reference without having to specify the actual type (I don't want to have to create method overloads for all value types if I can avoid it).</p> <p>Any other suggestions also welcomed. Thanks</p> <p><strong>UPDATE</strong></p> <p>After trying several different ways I eventually settled on the simple approach of passing a <code>Func&lt;T&gt;</code> into the <code>AddToDebug</code> method as shown below. I realised that, at least at the moment, I don't need the underlying value but only a formatted string representation of it.</p> <p>In the future I may expand the library to automatically scan a passed in type and display values of all its members. If it comes to that I will likely use the suggestion from @Hans Passant to pass in a reference to the Class in question.</p> <p>That said I will accept the answer from @Lee as it was most useful in my final implementation by suggesting the use of <code>Func</code>.</p> <p>This is the code I have now and would welcome any suggestions for improvement. Thank you all for your help.</p> <pre><code> public void AddToDebug&lt;T&gt;(Func&lt;T&gt; getValue, Color? color = null) { var w = new DebugEntry&lt;T&gt;(getValue, color.HasValue ? color.Value : Color.White); _values.Add(w); } public class DebugEntry&lt;T&gt; : IStringFormatter { private readonly Func&lt;T&gt; _getValue; public Color Color { get; private set; } public DebugEntry(Func&lt;T&gt; getValue, Color color) { _getValue = getValue; Color = color; } public string ToFormattedString() { return _getValue.Invoke().ToString(); } } public interface IStringFormatter { string ToFormattedString(); Color Color { get; } } // Example usage VD.AddToDebug(() =&gt; _counter); VD.AddToDebug(() =&gt; String.Format("This message says {0} times", _message)); </code></pre>
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