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The following example shows the same properties being set as in the previous attribute syntax example, but this time by using property element syntax for all properties of the Button. If an attribute syntax is possible, using the attribute syntax is typically more convenient and enables a more compact markup, but that is often just a matter of style, not a technical limitation. After specifying the content, you must close the property element with an end tag. Generally, the content of that tag is an object element of the type that the property takes as its value. The syntax for the property element start tag is. For these cases, a different syntax known as property element syntax can be used. įor some properties of an object element, attribute syntax isn't possible, because the object or information necessary to provide the property value can't be adequately expressed within the quotation mark and string restrictions of attribute syntax. For example, the following markup creates a button that has red text and a blue background with a display text of Content. The value of an attribute is always specified as a string that is contained within quotation marks.Īttribute syntax is the most streamlined property setting syntax and is the most intuitive syntax to use for developers who have used markup languages in the past. The attribute syntax names the object property that is being set, followed by the assignment operator (=). Properties of an object can often be expressed as attributes of the object element. Each instance is created by calling the parameterless constructor of the underlying type when parsing and loading the XAML. When you specify an object element tag, you create an instruction for XAML processing to create a new instance of the underlying type. The object elements StackPanel and Button each map to the name of a class that is defined by WPF and is part of the WPF assemblies. This specifies two object elements: (with content, and a closing tag later), and (the self-closing form, with several attributes). For example, look at the previously shown markup snippet again. You can instead use a self-closing form that doesn't have any content, by completing the tag with a forward slash and closing angle bracket in succession ( />). Object element syntax always starts with an opening angle bracket ( ). That type is defined in the assemblies referenced by the technology that uses XAML as a language. XAML object elementsĪn object element typically declares an instance of a type. The XAML language defines concepts of its own, but these concepts work within the XML language and markup form. This is a consequence of one of the basic design principles of XAML. Much of the material in the next few sections will be elementary to you if you have previous familiarity with the XML language. For more information about the specifics of XAML syntax, see XAML Syntax In Detail. These sections aren't intended to provide complete information about each syntax form, such as how these are represented in the backing type system. The following sections explain the basic forms of XAML syntax, and give a short markup example. This example is intended to give you a flavor of how XAML represents common UI programming metaphors (it's not a complete sample). The following example shows how you might create a button as part of a UI. The files can be encoded by any XML encoding, but encoding as UTF-8 is typical. When represented as text, XAML files are XML files that generally have the. XAML enables a workflow where separate parties can work on the UI and the logic of an app, using potentially different tools. This is unlike most other markup languages, which are typically an interpreted language without such a direct tie to a backing type system. XAML directly represents the instantiation of objects in a specific set of backing types defined in assemblies.

You can create visible UI elements in the declarative XAML markup, and then separate the UI definition from the run-time logic by using code-behind files that are joined to the markup through partial class definitions. NET Core programming model, XAML simplifies creating a UI for a.