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    <p>You have not actually overriden the <code>TabStop</code> property, because <a href="http://msdn.microsoft.com/en-us/library/system.windows.forms.control.tabstop.aspx" rel="nofollow">it is not virtual</a>.</p> <p><em>What you have done is "hidden" it by creating another property with the same name</em>. Therefore, a different property setter is executed when you try to set <code>Control.TabStop</code> here:</p> <pre><code>// The static type of c is Control! if (((ClassA)c).Properties.ReadOnly) c.TabStop = false; </code></pre> <p>And when you set it here:</p> <pre><code>// The static type is now ClassA ((ClassA)c).TabStop = false; </code></pre> <p>When you refer to the property, the compiler resolves the name using <strong>static</strong> binding because it is not virtual. For that reason if you do not cast the object to something more derived than <code>Control</code>, you will not see your own code run.</p> <p><strong>Update:</strong> This still leaves some open questions:</p> <ol> <li>Why does the compiler bind to <code>MyControl.TabStop</code> if the static type of the variable is <code>ClassA</code>? Shouldn't it still bind to <code>Control.TabStop</code>?</li> <li>Why does the compiler let you write <code>Public Overrides Property TabStop As Boolean</code> if <code>Control.TabStop</code> is not virtual?</li> </ol> <p>We know that there has to be <em>some</em> class in the hierarchy between <code>Control</code> and <code>MyControl</code> with a virtual <code>TabStop</code> property (otherwise <code>Overrides</code> on <code>MyControl.TabStop</code> would be a compiler error). We also know that <code>ClassA.TabStop</code> ends up binding to <code>MyControl.TabStop</code>. Assuming that there is no other class in the hierarchy between <code>Control</code> and <code>ClassA</code>, there is only one logical explanation: class <code>ClassA</code> defines a virtual <code>TabStop</code> property that <code>Shadows</code> <code>Control.TabStop</code>.</p>
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    1. POHow does C# do dynamic binding?
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    1. COI'll add that this confusion is "normal" for people that come from Java experience: there all non static methods are virtual by default (unless you mark them with private or final).
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    2. COOk, your answer makes sense for the first part. Thanks for that. But it does not explain the second part. If I make the assigment like " ((ClassA)c).TabStop = false ", the code in MyClass is run. Why?
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    3. CO@e-mre: That's a very good question. Possibly `ClassA` `Shadows` the property `TabStop` with a new virtual property, which `MyClass` then overrides? Can't say without looking at the definitions for all classes in the hierarchy.
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