Establishes the handler for the Resized event that occurs whenever the ActualHeight or ActualWidth property of the Silverlight plug-in changes.

<object ...>
  <param name="onresize" value="scriptHandlerName" />
value = silverlightObject.content.OnResize
silverlightObject.content.OnResize = scriptHandlerName



The object (the Silverlight plug-in) that invoked the event.



This parameter is always set to null.

The Resized event occurs whenever the Silverlight plug-in changes its ActualHeight or ActualWidth property in embedded mode.

If a change in size of the Silverlight plug-in triggers the FullScreenChanged event you handle with OnFullScreenChanged, the Resized event does not occur. In addition, the Resized event does not occur when the Silverlight plug-in is in full-screen mode.

In embedded mode, the plug-in displays in the Web browser window. In full-screen mode, the plug-in displays on top of all other applications.


Silverlight does not support automatic layout of elements based on changes to the plug-in size. This means that applications have to provide logic to resize themselves appropriately when the plug-in size changes.


Handle with OnResize event instead of OnLoad to make sizing decisions. This is because the actualHeight and actualWidth values of the Silverlight plug-in are not guaranteed to be set at the time the Loaded event occurs. Resize occurs whenever the ActualHeight or ActualWidth properties change, including when the plug-in first loads.

The following JavaScript example shows how to define a OnResize event handler for a Silverlight plug-in.

var plugin;

function onLoaded(sender, args)
    // Retrieve a reference to the plug-in.
    var slPlugin = sender.getHost();
    // Set the event handler function to the OnResize event.
    slPlugin.content.onResize = onResized;

    // Do initial layout of the application based on initial size.
    updateLayout(slPlugin.content.actualWidth, slPlugin.content.actualHeight);

function onResized(sender, eventArgs)
    // Do layout resizing of the application whenever the plug-in actualwidth or actualheight changes.
    updateLayout(slPlugin.content.actualWidth, slPlugin.content.actualHeight);

// Resize and reposition application elements.
function updateLayout(width, height)
    // Perform layout tasks based on width and height.

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