XAttribute Explicit Conversion (XAttribute to Nullable<Boolean>)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Cast the value of this XAttribute to a Nullable<T> of Boolean.
Assembly: System.Xml.Linq (in System.Xml.Linq.dll)
Parameters
- attribute
- Type: System.Xml.Linq.XAttribute
The XAttribute to cast to Nullable<T> of Boolean.
Return Value
Type: System.Nullable<Boolean>A Nullable<T> of Boolean that contains the content of this XAttribute.
| Exception | Condition |
|---|---|
| FormatException | The attribute does not contain a valid Boolean value. |
When converting to Boolean from an attribute or element, allowed values are "0", "1", and any string that produces "true" or "false" after trimming and conversion to lower case.
The following example creates an attribute with Boolean content. It then retrieves the value by casting to Nullable<T> of Boolean.
StringBuilder output = new StringBuilder(); XElement root = new XElement("Root", new XAttribute("BoolValue1", true), new XAttribute("BoolValue2", false) ); bool? bool1 = (bool?)root.Attribute("BoolValue1"); bool? bool2 = (bool?)root.Attribute("BoolValue2"); output.Append("Nullable boolean: BoolValue1=" + bool1); output.Append(Environment.NewLine); output.Append("Nullable boolean: BoolValue2=" + bool2); output.Append(Environment.NewLine); OutputTextBlock.Text = output.ToString();