QR Code Drawer In Visual Basic .NET
Using Barcode maker for VS .NET Control to generate, create Denso QR Bar Code image in Visual Studio .NET applications.www.OnBarcode.com
Decoding QR Code In VB.NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.www.OnBarcode.com
XAML is a declarative language that enables you to create and initialize .NET objects in XML. Everything you can do in XAML you can do in code. But to make the most of the
Drawing Code 128 Code Set C In VB.NET
Using Barcode creation for .NET Control to generate, create Code 128C image in .NET framework applications.www.OnBarcode.com
Print UPC Code In Visual Basic .NET
Using Barcode maker for .NET Control to generate, create UPC A image in VS .NET applications.www.OnBarcode.com
platform and its tooling, you ll want to embrace the code-plus-markup philosophy rather than go with a 100 percent code solution. The XAML format enables you to easily visualize a hierarchy of elements while separating presentation from code. This separation is possible because each XAML element maps to a .NET type. Each attribute within an element corresponds to a property within a .NET type. This concept is illustrated in figure 2.1. Figure 2.1 shows three code equivalents of an XAML segment. Note that the TextBlock element in the XAML code corresponds to an initialization statement within the code segments. This initialization occurs because, each time an element is created in XAML, the corresponding .NET type s default constructor is called behind the scenes. To understand the structure of an XAML file, it s important to understand the representation and use of objects, namespaces, properties, and events.
Creating EAN / UCC - 14 In Visual Basic .NET
Using Barcode generation for Visual Studio .NET Control to generate, create EAN 128 image in Visual Studio .NET applications.www.OnBarcode.com
Generate QR Code In Visual Basic .NET
Using Barcode printer for .NET framework Control to generate, create Denso QR Bar Code image in VS .NET applications.www.OnBarcode.com
Download from Wow! eBook <www.wowebook.com>
Code 39 Full ASCII Maker In VB.NET
Using Barcode creator for VS .NET Control to generate, create Code-39 image in VS .NET applications.www.OnBarcode.com
2/5 Standard Generation In VB.NET
Using Barcode printer for .NET framework Control to generate, create C 2 of 5 image in .NET framework applications.www.OnBarcode.com
QR Code JIS X 0510 Creation In .NET
Using Barcode generation for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.www.OnBarcode.com
Print QR Code 2d Barcode In Java
Using Barcode generation for BIRT Control to generate, create QR Code ISO/IEC18004 image in BIRT reports applications.www.OnBarcode.com
<TextBlock x:Name="tb" Text="Hello, World" FontFamily="Verdana"/>
UCC.EAN - 128 Generation In .NET Framework
Using Barcode printer for Reporting Service Control to generate, create UCC.EAN - 128 image in Reporting Service applications.www.OnBarcode.com
Encoding Barcode In None
Using Barcode creator for Office Word Control to generate, create Barcode image in Microsoft Word applications.www.OnBarcode.com
Figure 2.1 XAML markup represents .NET objects. Anything you can do in XAML you can do in code.
European Article Number 13 Scanner In C#
Using Barcode recognizer for .NET Control to read, scan read, scan image in .NET applications.www.OnBarcode.com
Make 2D In .NET Framework
Using Barcode generation for ASP.NET Control to generate, create Matrix Barcode image in ASP.NET applications.www.OnBarcode.com
Recognizing PDF 417 In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.www.OnBarcode.com
Paint Code-39 In Visual C#
Using Barcode creator for .NET Control to generate, create Code 3 of 9 image in Visual Studio .NET applications.www.OnBarcode.com
Code 39 Printer In None
Using Barcode drawer for Online Control to generate, create Code 3 of 9 image in Online applications.www.OnBarcode.com
Generate Quick Response Code In Java
Using Barcode drawer for BIRT Control to generate, create QR Code ISO/IEC18004 image in Eclipse BIRT applications.www.OnBarcode.com
PDF417 Encoder In None
Using Barcode generation for Word Control to generate, create PDF417 image in Microsoft Word applications.www.OnBarcode.com
Printing DataMatrix In C#
Using Barcode maker for .NET framework Control to generate, create Data Matrix ECC200 image in .NET applications.www.OnBarcode.com
tb = wpf.TextBlock() tb.Text = "Hello, World" tb.FontFamily = "Verdana"
Dim tb As New TextBlock tb.Text = "Hello, World" tb.FontFamily = "Verdana"
TextBlock tb = new TextBlock(); tb.Text = "Hello, World"; tb.FontFamily = "Verdana";
Objects (or instances of types) are represented in XAML using XML elements. The elements have the same name as the associated class and are considered instantiated upon declaration in the markup.
NOTE Any type you use in XAML must have a default (parameterless) constructor. Silverlight XAML currently has no provision for passing arguments into a constructor or an initialization function, so you ll need to make sure your types can be initialized using defaults and properties alone.
Certain types of objects may contain one or more of other nested objects. For example, a button may contain a single content object, which itself may contain one or more other objects. In listing 2.1, the UserControl contains the Grid, the Grid contains the Button, and the Button contains a StackPanel, which is a panel that by default lays its children out in a vertical list. The StackPanel itself contains three TextBlock elements.
Listing 2.1 XAML showing a hierarchy of nested objects
Download from Wow! eBook <www.wowebook.com>
XAML basics XAML:
<UserControl x:Class="XamlElements.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> Nested Grid <Grid x:Name="LayoutRoot"> <Button Height="100" Width="150"> Button nested in Grid <StackPanel> <TextBlock Text="First Line" /> StackPanel Three inside Button <TextBlock Text="Second Line" /> TextBlocks in StackPanel <TextBlock Text="Third Line" /> </StackPanel> </Button> </Grid> </UserControl>
The UserControl and Button are both content controls, a concept we ll discuss in greater detail in chapter 10. For now, it s important to understand that a content control may only have one direct child element, typically a panel that holds other elements. The x:Name and x:Class properties are part of the namespace specified by the xmlns:x statement. More on that in a moment The Grid and StackPanel are both Panels, which is a type that has a Children collection to allow multiple contained elements. We ll discuss panels in chapter 7. The ability to flexibly nest objects permits a composition approach to UI design. Rather than having to purchase or custom-code a button control that allows, say, three lines of text and an image, you can simply compose those into an appropriate layout panel and make that panel the content of the button control. The nesting of objects is part of what gives us an object tree. We ll cover that in more detail shortly. Now that we ve covered the basic structure of an XAML file, let s talk about how you differentiate your SuperButton control from my SuperButton control, even though we used the same control name: namespaces.
Namespaces A namespace provides a way of organizing related objects within a common grouping. These groupings, or namespaces, give you a way to define where the compiler should look for a type. Namespaces in XAML are similar to namespaces in other languages such as C# and Java. To specify where to look, you reference a namespace within an element of an XAML file, typically the root or outermost element. Listing 2.2 illustrates the use of the two default namespaces.