Displayable类说明文档

public abstract class Displayable

extends Object

 

能够被显示在display上的对象。一个Displayable对象可以包含一个标题，一个滚动条，零个或多个和命令监听器相联的命令。被显示的部件和与用户的交互行为由该类的子类定义。

 

标题栏可以包含换行符。标题的显示也要相应的换行。比如，如果只有一行可以用来显示标题并且标题字符串包含一个换行符，那么只有在换行符前面的字符会被显示出来。

 

除了子类有特殊定义，新创建的Displayable对象状态如下：

 

对象在屏幕上不可见；

对象没有相关联的滚动条；

对象的标题为空；

对象不含命令以及相关联的命令监听器

javax.microedition.lcdui
Class Displayable

java.lang.Object
  javax.microedition.lcdui.Displayable

Direct Known Subclasses:

Canvas, Screen

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public abstract class Displayable extends Object

An object that has the capability of being placed on the display. A Displayable object may have a title, a ticker, zero or more commands and a listener associated with it. The contents displayed and their interaction with the user are defined by subclasses.

The title string may contain line breaks. The display of the title string must break accordingly. For example, if only a single line is available for a title and the string contains a line break then only the characters up to the line break are displayed.

Unless otherwise specified by a subclass, the default state of newly created Displayable objects is as follows:

• it is not visible on the Display;
• there is no Ticker associated with this Displayable;
• the title is null;
• there are no Commands present; and
• there is no CommandListener present.

 

 

Since:

MIDP 1.0

 

                                                                                                                                          翻译: lori.wang