Preface XV in Software

Encoding qr-codes in Software Preface XV

Figure 9-13

public event MyEventHandler SomeEvent; // This is called to raise the event. public void OnSomeEvent() { if(SomeEvent != null) SomeEvent(); } } class X { int id; public X(int x) { id = x; } // This is an instance method that will be used as an event handler. public void Xhandler() { Console.WriteLine("Event received by object " + id); } } class EventDemo3 { static void Main() { MyEvent evt = new MyEvent(); X o1 = new X(1); X o2 = new X(2); X o3 = new X(3); evt.SomeEvent += o1.Xhandler; evt.SomeEvent += o2.Xhandler; evt.SomeEvent += o3.Xhandler; // Raise the event. evt.OnSomeEvent(); } }

You don t have to go the menu route to clip an object to a container if you have a little skill with a mouse or any input device that has a right-click feature. Creating PowerClips interactively involves a right mouse button click-drag, and the following tutorial walks you through the steps. Additionally, the next steps show you how to adjust the position of a contained object relative to its container, so you have exactly the areas you want peeking through. Download Postcard.zip and then extract the contents to a place on hard disk that s easy to locate. The zip archive contains all the elements you ll need to work through the creation of a vintage postcard. The following set of steps is an excursion into Pop Art; one of the more popular visual effects seen on postcards from the 1950s was the peekaboo scenery poking through bold text naming the state or city. This was an expensive process to create, which required patience and talent, neither of which is necessary once you re comfortable working with PowerClips! By default, contained objects are centered in the PowerClip container, and this

19:

#include <stdio.h> int main(void) {

However, the use of enum here is redundant. In C (which also supports enumerations), this second form was required, so you may see it used in some programs. Assuming the preceding declarations, the following types of statements are perfectly valid:

Mnemonic IMA_RESULT_LOGON_USER_ DISABLED IMA_RESULT_CMC_ CONNECTION_DISABLED IMA_RESULT_INSUFFICIENT_ SERVER_SEC_FOR_USER IMA_RESULT_FEATURE_ LICENSE_NOT_FOUND IMA_RESULT_DISALLOW_CMC_ LOGON IMA_RESULT_NW_PRINT_ SERVER_ALREADY_PRESENT IMA_RESULT_SERVER_ ALREADY_PRESENT IMA_RESULT_TABLE_NOT_ FOUND IMA_RESULT_NOT_TABLE_ OWNER IMA_RESULT_INVALID_QUERY IMA_RESULT_TABLE_OWNER_ HAS_CHANGED IMA_RESULT_SERVICE_NOT_ AVAILABLE IMA_RESULT_ZONE_MASTER_ UNKNOWN IMA_RESULT_NON_UNIQUE_ HOSTID IMA_RESULT_REG_VALUE_NOT_ FOUND IMA_RESULT_PARTIAL_LOAD

An important formula in the calculus relates the derivative of the inverse of a function to the derivative of the function itself. The formula is [ f 1 ] (t) = 1 f ( f 1 (t)) . ( )

Properties have some important restrictions. First, because a property does not define a storage location, it cannot be passed as a ref or out parameter to a method. Second, you cannot overload a property. (You can have two different properties that both access the same underlying variable, but this would be unusual.) Finally, a property should not alter the state of the underlying variable when the get accessor is called. Although this rule is not enforced by the compiler, such an alteration is semantically wrong. A get operation should not create side effects.