c# pdf417 Design Patterns for Building Message-Oriented Web Services in visual C#.net

Writer PDF417 in visual C#.net Design Patterns for Building Message-Oriented Web Services

You can see from the figure that I have used TextBox controls in place of the Windows Forms NumericUpDown controls. Another change is that I have used a TextBlock, which is a convenient way of displaying a paragraph of text. The TextBlock control is selected in Figure 33-3 because you can t see its borders when it is not selected. When you drag controls around the design surface, you ll see red lines appear that indicate how the current position relates to other controls. You can use these lines to guide your alignment, or you can edit the XAML document to position your controls precisely. WPF provides a good selection of layout controls that will position other controls based on some kind of policy. We are using the Grid layout that is added to new projects by default, but there are others available if you want a more sophisticated approach. Even the Grid control allows you to position controls manually or to create rows and columns that you can use to add structure to your layout. When you click a control, you will see that there are lines that reach out from the control to the edge of the Grid control. If you click the small arrow at the control end of the line, the line will disappear. If you click the small circle, the line will reappear. Figure 33-4 shows what the design surface looks like when all four lines have been created.

Table 8-1 describes primitive data types and their respective ILAsm notation. Table 8-1. Primitive Data Types Defined in the Runtime

Once we have added an Assert statement, we can test until we find where the zero value arises and then remove the Assert method call. It would be nice if we could leave the statement there. After all, if the zero value is a big deal, then we always want to know when it arises. But such a statement will provide a miniscule amount of drag on the performance of our program, and we don t want our users to see the dialog box that is displayed when a zero value does arise. Fortunately, we don t need to remove the Assert statement. It is removed for us when we compile our program for release. When you create a new project, Visual Studio configures it such that the Debug build mode is used. This includes all sorts of additional information that is useful for debugging your program. All that additional information is striped out when you switch to the Release mode, and so are the calls to the Debug class. To switch to the Release mode, select the Configuration Manager item from the Build menu. This will show the Configuration Manager dialog box, as shown by Figure 38-3. Click the item in the Configuration column for the project you want to change, and select Release from the drop-down list.

It is important that you also ensure that the security on the virtual root itself (within IIS) is configured to allow anonymous users. If IIS blocks anonymous users, then it doesn t really matter what kind of security you use within ASP.NET.

The ASP.NET AJAX libraries can be easily integrated with WCF Data Services. If you are unfamiliar with WCF Data Services, please refer to 9 for more in-depth details of how to create a service.

// enumerate the contents of the counter foreach (int i in count) { Console.WriteLine("Value: {0}", i); } // wait for input before exiting Console.WriteLine("Press enter to finish"); Console.ReadLine(); } } In this example, the Counter class has a private field that is an array of int values. The iterator block uses a foreach loop to enumerate the contents of the loop and the yield return statement to return each value. Compiling and running the code in Listing 9-57 produces the following results: Value: 2 Value: 4 Value: 6 Value: 8 Value: 10 Press enter to finish If the field you want to expose through an iterator block is a collection or an array, as was the case in the previous example, then there is an alternative approach. Collection classes (described in a later part of this book) and arrays (described in 13) implement their own iterator blocks, which means that we can simply return the result of their implementation of the GetEnumerator method. There is a small wrinkle when using arrays in this way, in that in order to get a strongly typed IEnumerator<T>, we have to cast the array to an IList<T>, as follows: using System.Collections.Generic; class Counter { private int[] arrData = {2, 4, 6, 8, 10}; public IEnumerator<int> GetEnumerator() { return ((IList<int>)arrData).GetEnumerator(); } }