Edit a style
You can use the style of a control in Microsoft Expression Blend project to specify triggers (Windows Presentation Foundation) or states (Microsoft Silverlight) and properties that will be used as defaults by the control to which the style is applied. The properties (such as the background brush color) will affect the appearance of the control, and the triggers or states will affect how the control responds to property changes and events. For example, when a user moves the pointer over the control, the IsMouseOver property changes from False to True and the MouseOver event fires. You can create a style for a button that causes the background color of the button to change when the pointer moves over the button.
Style resources save you time by allowing you to define the appearance and behavior for a type of control, and then apply that style to multiple instances of that type of control on the artboard. When you modify a style resource, all of the controls on the artboard that use that style are automatically updated.
On the artboard or in the Objects and Timeline panel, select the object whose style you want to edit.
On the Object menu, point to Edit Style, and then click Edit Current.
If the Edit Current option is unavailable, the object does not have a custom style applied to it. If you choose Edit a Copy, you will create a style resource that is a copy of the default style.
Under Miscellaneous in the Properties panel, click the Style property, and then click Edit Resource.
If the Style property is empty, the object does not have a custom style applied to it.
Expression Blend enters the editing scope for the style.
Notice the new Expression Blend breadcrumb bar at the top of the artboard.
By clicking the buttons on the breadcrumb bar, you can quickly move between template-editing mode, style-editing mode, and object-editing scope for the selected object. The breadcrumb bar appears for any selected object that has a custom style or template applied to it.
While in the editing scope for a style, add your property and event triggers in the Triggers panel.
For an example of triggers that you can set, see Create a control from existing objects.
To exit the editing scope of the style, click Return scope to in the Objects and Timeline panel. This returns you to the editing scope of the document.
Notice that after you create a new style resource for an object or apply an existing style resource to an object, a green highlight appears in the Properties panel for the Style property of the selected object, to indicate that the object is now bound, or linked, to the style resource.