Nullable<T>.HasValue Property
Silverlight
Gets a value indicating whether the current Nullable<T> object has a value.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Property Value
Type: System.Booleantrue if the current Nullable<T> object has a value; false if the current Nullable<T> object has no value.
If the HasValue property is true, the value of the current Nullable<T> object can be accessed with the Value property.
The following code example returns the value of a Nullable<T> object if that object has a defined value; otherwise, a default value is returned.
// This code example demonstrates the Nullable<T>.HasValue // and Value properties. using System; class Example { public static void Demo(System.Windows.Controls.TextBlock outputBlock) { DateTime? myNow; // Assign the current date and time to myNow then display its value. myNow = DateTime.Now; Display(outputBlock, myNow, "1) "); // Assign null (Nothing in Visual Basic) to myNow then display its value. myNow = null; Display(outputBlock, myNow, "2) "); } // Display the date and time. public static void Display(System.Windows.Controls.TextBlock outputBlock, DateTime? displayDateTime, string title) { // If a value is defined for the displayDatetime argument, display its value; otherwise, // display that no value is defined. outputBlock.Text += title; if (displayDateTime.HasValue == true) outputBlock.Text += String.Format("The date and time is {0:F}.", displayDateTime.Value) + "\n"; else outputBlock.Text += "The date and time is not defined." + "\n"; } } /* This code example produces the following results: 1) The date and time is Tuesday, April 19, 2005 4:16:06 PM. 2) The date and time is not defined. */
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
