javax.swing.plaf
介面 UIResource

所有已知實作類別：

ActionMapUIResource, BasicBorders.ButtonBorder, BasicBorders.FieldBorder, BasicBorders.MarginBorder, BasicBorders.MenuBarBorder, BasicBorders.RadioButtonBorder, BasicBorders.RolloverButtonBorder, BasicBorders.SplitPaneBorder, BasicBorders.ToggleButtonBorder, BasicComboBoxEditor.UIResource, BasicComboBoxRenderer.UIResource, BasicTextUI.BasicCaret, BasicTextUI.BasicHighlighter, BorderUIResource, BorderUIResource.BevelBorderUIResource, BorderUIResource.CompoundBorderUIResource, BorderUIResource.EmptyBorderUIResource, BorderUIResource.EtchedBorderUIResource, BorderUIResource.LineBorderUIResource, BorderUIResource.MatteBorderUIResource, BorderUIResource.TitledBorderUIResource, ColorUIResource, ComponentInputMapUIResource, DefaultListCellRenderer.UIResource, DefaultMenuLayout, DefaultTableCellRenderer.UIResource, DimensionUIResource, FontUIResource, IconUIResource, InputMapUIResource, InsetsUIResource, JScrollPane.ScrollBar, MetalBorders.ButtonBorder, MetalBorders.Flush3DBorder, MetalBorders.InternalFrameBorder, MetalBorders.MenuBarBorder, MetalBorders.MenuItemBorder, MetalBorders.OptionDialogBorder, MetalBorders.PaletteBorder, MetalBorders.PopupMenuBorder, MetalBorders.RolloverButtonBorder, MetalBorders.ScrollPaneBorder, MetalBorders.TextFieldBorder, MetalBorders.ToggleButtonBorder, MetalBorders.ToolBarBorder, MetalCheckBoxIcon, MetalComboBoxEditor.UIResource, MetalIconFactory.PaletteCloseIcon, ScrollPaneLayout.UIResource

public interface UIResource

此介面用於標記由 ComponentUI 委託創建的物件。ComponentUI.installUI() 和 ComponentUI.uninstallUI() 方法可以使用此介面確定屬性值是否已經被覆寫。例如，JList cellRenderer 屬性只在其初始值為 null 時由 BasicListUI.installUI() 初始化：

 if (list.getCellRenderer() == null) {
     list.setCellRenderer((ListCellRenderer)(UIManager.get("List.cellRenderer")));
 }
 

在執行 uninstallUI() 時，如果該屬性的值是 UIResource 的一個實例，則將該屬性重置為 null：

 if (list.getCellRenderer() instanceof UIResource) {
     list.setCellRenderer(null);
 }

此網要應用於除 java.awt.Component 屬性 font、foreground 和 background 之外的所有屬性。如果這些屬性中有一個未被初始化，或者被顯式設置為 null，則其容器將提供該值。因此，在調用 installUI() 來動態更新元件外觀時，"== null" 是不可靠的。因此，在執行 installUI() 時，要檢查當前值是否是一個 UIResource：

 if (!(list.getFont() instanceof UIResource)) {
     list.setFont(UIManager.getFont("List.font"));
 }
 

另請參見：

ComponentUI