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The Employee class has a property called Emails that is of type string array. Under the default naming scheme, when this property is serialized, an XML node is created with the name Emails. This node further contains child nodes, each containing the array element value. The names of the child elements are the same as the data type of the array (<string> in our example). You can alter this behavior with the help of the [XmlArray] and [XmlArrayElement] attributes. The former marks public members that are array types and specifies the XML element name for the member. The latter attribute governs the name of the XML element

When a user resizes a form, the controls maintain a constant distance from the edges of its parent form with the help of the Anchor property. The default value for the Anchor property for any control is set to Top, Left, which means that this control will maintain a constant distance from the top and left edges of the form. The Anchor property can be set by using the provided graphical interface in the Properties window, as shown in Figure 14-12. Due to the default setting of Anchor property to Top, Left, if you try to resize a form by stretching it toward the right side, you will see that its controls are still positioned on the left rather than shifting to the center of the form to adjust to the size of the form after resizing is done. If opposite edges, for example, Left and Right, are both set in the Anchor property, the control will stretch when the form is resized. However, if neither of the opposite edges is set in the Anchor property, the control will float when the parent is resized.

atoms[i]->DecayProcess = gcnew DecayProcessFunc(&RadioactiveAtom::SomeStaticMethod); So far we ve used delegates but not events. An event is an abstraction representing something happening. Methods called event handlers may be hooked up to events to respond in some way to the event. Events are of type delegate, but as you ve seen, delegates themselves may be used independently of events. The delegate forms a link between the source of the event (possibly a user action, or some action initiated by other code) and the object and function that responds in some way to the action. In this case, the RadioactiveAtom class will have a Decay event, declared as in Listing 2-12. Listing 2-12. Declaring an Event ref class RadioactiveAtom { // other code... // the event declaration event DecayProcessFunc^ Decay; }; Instead of invoking the delegate directly, we call the event in the client code using functioncall syntax. The code that hooks up the event looks the same as with the delegate property (see Listing 2-13). Listing 2-13. Hooking Up and Firing an Event // Hook up the event. atoms[i]->Decay += gcnew DecayProcessFunc(atoms[i], &RadioactiveAtom::BetaDecay); // ... // Fire the event. a->Decay(); It is possible for an event to trigger multiple actions. You ll learn about such possibilities in 7. You could certainly refine the design further. Perhaps you are bothered by the fact that every instance of RadioactiveAtom contains its own halflife and lambda properties. You might instead create a static data structure to store the half-life information for every type of isotope. What would this structure look like It would require two indices to look up: both the atomic number and the isotope. However, a two-dimensional array would be a huge waste of space, since most of the cells would never be used. You might try implementing an isotope table as a sparse array a data structure that can be used like an array but is a hashtable underneath so as to avoid storing space for unused elements. The implementation of such a collection type would probably be a template in classic C++. In C++/CLI, it could be a template or it could be another type of parameterized type, a generic type, which the next section describes.

When FileVault is enabled for the user, an additional attribute, HomeDirectory is populated:

let sumIfBothSmall (inp1,inp2) = attempt { let! n1 = failIfBig inp1 let! n2 = failIfBig inp2 let sum = n1 + n2 return sum } In this case, the let binding executes exactly as you would expect; it takes the expression n1+n2 and binds its result to the value sum. To summarize, you ve seen that computation expressions let you do the following: Use an expression-like syntax to build Attempt computations Sequence these computations together using the let! construct Return results from these computations using return and return! Compute intermediate results using let

The exact type is loaded, or a TypeLoadException is thrown. The type is loaded using only the type name and the assembly name. A TypeLoadException is thrown if this type doesn t exist. The exact type is loaded if present; if not, the type is loaded using only the type name and the assembly name. If the type doesn t exist, a TypeLoadException is thrown.2 The type is loaded using only the type name and the assembly name. A TypeLoadException is thrown if this type doesn t exist.

Figure 17-2. Memory organization of a running CLR program Dynamic memory is allocated in the heap, which is a data structure where data resides for an amount of time not directly related to the events of program execution. The memory is explicitly allocated by the program, and it s deallocated either explicitly or automatically depending on the strategy adopted by the runtime to manage the heap. In the CLR, the heap is managed by a garbage collector, which is a program that tracks memory usage and reclaims memory that is no longer used by the program. Data in the heap is always referenced from the stack or other known areas such as static memory either directly or indirectly. The garbage collector can deduce the memory potentially reachable by program execution in the future, and the remaining memory can be collected. During

The value returned is either PortletSession.PORTLET_SCOPE or PortletSession.APPLICATION_SCOPE. Both of these methods look at the name of the attribute to determine if it starts with the portlet scope namespace, which is javax.portlet.p .