vb.net qr code generator Figure 10-9. Culture Viewer in visual basic.net

Integrating qr codes in visual basic.net Figure 10-9. Culture Viewer

The following statements define an interface that contains a single method: public interface ICalc { int CalculateProduct(int x, int y); }

Figure 17-9 illustrates the code. Notice in the figure that the interface methods are not pointing at class-level implementations, but contain their own code.

Figure 1-3. Linking with managed library inputs Object file compatibility is an important feature because it allows you minimize the overhead of managed execution. If you use C++/CLI to integrate .NET code into existing C++ code, you will likely decide to compile most or even all of your existing code without /clr, and to compile only new files to managed code. In 7, I will explain what you should consider before you modify your project settings to turn on the /clr compiler switch, and I will give step-by-step instructions for modifying your project configurations.

The mechanics of a method calling itself are exactly the same as if it had called another, different method. A new stack frame is pushed onto the stack for each call to the method. For example, in the following code, method Count calls itself with one less than its input parameter and then prints out its input parameter. As the recursion gets deeper, the stack gets larger. class Program { public void Count(int inVal) { if (inVal == 0) return; Count(inVal - 1);

private EditableRootList() { /* Require use of factory methods */ } #endregion #region Data Access private void DataPortal_Fetch( SingleCriteria<EditableRootList, int> criteria) { RaiseListChangedEvents = false; // TODO: load values into memory object childData = null; foreach (var item in (List<object>)childData) this.Add(EditableChild.GetEditableChild(childData)); RaiseListChangedEvents = true; } #endregion } The Authorization Rules region implements the AddObjectAuthorizationRules() method to define the roles that can interact with the object. This is the same as with an editable root object, and the UI developer can use this information to enable and disable UI elements accordingly. Also, the data portal uses these rules to ensure only authorized users are able to create, get, edit, or delete the collection object. The one difference is that this AddObjectAuthorizationRules() method only needs to define the roles allowed to get the object. The Factory Methods region implements factory methods to create, retrieve, and (optionally) delete the collection. The methods rely on the data portal to do much of the work, ultimately delegating the call to the appropriate DataPortal_XYZ method. In the Data Access region, the DataPortal_Fetch() method is responsible for getting the data from the database using whatever data access technology you choose. This is often LINQ to SQL, the ADO.NET Entity Framework, or raw ADO.NET. In any case, the Data Access layer must return the child data as a result so it can use it to load each individual child object with data. You load each child object by calling the child object s factory method, passing the object s data as a parameter. The resulting child object is added to the collection. The DataPortal_Fetch() method sets the RaiseListChanged Events property to false before changing the collection, and then restores it to true once the operation is complete. Setting this property to false tells the base BindingList<T> class to stop raising the ListChanged event. When doing batches of updates or changes to a collection, this can increase performance. The BusinessListBase class includes a default implementation of the DataPortal_Update() method, which loops through all child objects (and deleted child objects) to ensure the appropriate Child_XYZ method is called on each when the collection is being saved. Normally this is the desired behavior, but you can override DataPortal_Update() if you need to take control of the update process for some unusual scenario. As with the editable root stereotype, you can use the ObjectFactory attribute to have the data portal invoke an object factory rather than invoke the DataPortal_XYZ methods directly in the business class. Collection objects that inherit from BusinessListBase automatically support data binding in WPF, Windows Forms, and Web Forms. However, if you bind a collection to a Windows Forms DataGrid control, you may be surprised to find that the user can t just add new items by going to the bottom of the grid. You need to write a bit of extra code in your collection to enable this behavior.

A delegate can be implicitly converted to the .NET BCL classes and interfaces shown in Figure 18-19. An array, ArrayS, with elements of type Ts, can be implicitly converted to the following: The .NET BCL class and interfaces shown in Figure 18-19. Another array, ArrayT, with elements of type Tt, if all of the following are true: Both arrays have the same number of dimensions. The element types, Ts and Tt, are reference types not value types. There is an implicit conversion between types Ts and Tt.

To create a first-person camera, you will need to keep track of four variables: the amounts of rotation around the Up and Right vectors, the position of your camera, and the MouseState that corresponds to the mouse cursor centered in the window. A key press or movement of the mouse will be detected in the update cycle, which triggers the changes to these variables and results in a new View matrix being created, based on the new values. protected override void Initialize() { base.Initialize(); float viewAngle = MathHelper.PiOver4; float aspectRatio = (float)this.Window.ClientBounds.Width / (float)this.Window.ClientBounds.Height; float nearPlane = 0.5f; float farPlane = 100.0f;

Figure 11-15. Sample ZedGraph chart As such, ZedGraph makes an excellent choice for use in an Atlas-based project and is easy to implement in your applications. You simply make a reference to the ZedGraph.DLL in your solution and add the ZedGraph tools to your Toolbox in the standard way.

private static KeyPair generateDSAKeyPair() throws NoSuchAlgorithmException { KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA"); kpg.initialize(1024, new SecureRandom()); return kpg.generateKeyPair(); }