出自UXGuide.net

使用系统自带的按钮与图标

Using System-Provided Buttons and Icons

iPhone OS makes available many of the standard toolbar and navigation bar buttons, tab bar items, and general-use buttons used throughout the built-in applications. You can see a handful of standard toolbar buttons in the Mail toolbar, shown in Figure 10-1.

iPhone OS 在其内置的应用程序中贯穿使用了大量的标准工具栏和导航栏按钮、标签栏项及常规按钮等。你可以在 Mail 的工具栏上看到不少标准的工具栏按钮，如图 10-1 所示。

Figure 10-1  Standard buttons in the Mail toolbar
图 10-1 Mail 工具栏中的标准按钮

Buttons such as the Refresh, Organize, Trash, Reply, and Compose buttons shown in Figure 10-1 are used consistently in many of the built-in applications, so users are well-acquainted with what they mean and how to use them. This means that if your application supports these functions, you can take advantage of users’ familiarity to streamline the application’s user interface. It also means that if you associate these buttons with other tasks, you’re likely to confuse and irritate users by promising functionality they expect, but delivering something else.

图 10-1 中如刷新、组织、删除、回复和撰写等按钮在许多内置应用程序中都被一致地使用，因此用户很熟悉其含义和用法。这意味着如果你的应用程序也支持这些功能的话，你便可以利用用户已经熟知这一点来优化应用程序的用户界面。相反，如果你将这些按钮用于其他的任务，你则可能会使用户感到糊涂甚至愤怒，因为你暗示的是某种他们期望得到的功能，而事实却相反。

In addition to the benefit of leveraging users’ prior experience, using system-provided buttons and icons imparts two other substantial advantages, specifically:

除了可以充分利用用户先前经验的好处之外，使用系统自带的按钮和图标还将产生另外两个重要的影响，分别是：

• Decreased development time, because you don’t have to create custom art to represent standard functions.

减少开发时间，因为你无须为了展现标准功能而自行创建自定义的图形。

• Increased stability of your user interface, even if future iPhone OS updates change the appearances of standard icons. In other words, you can rely on the semantic meaning of a standard icon remaining the same, even if its appearance changes.

增加用户界面的稳定性，哪怕未来 iPhone OS 的更新版本更改了这些标准图标的外观。换句话说，你可以相信即使标准图标的外观变了，其语义仍将保持不变。

It bears repeating that to realize the advantages of user familiarity, shorter development time, and semantic consistency of the user interface, you must use the buttons and icons appropriately. Specifically, this means that you should use a button or icon in accordance with its documented meaning and recommended placement, and not according to your interpretation of its appearance. See “Standard Buttons for Use in Toolbars and Navigation Bars,” “Standard Icons for Use in Tab Bars,” and “Standard Buttons for Use in Table Rows and Other User Interface Elements” for meaning and placement information for the system-provided buttons and icons.

再次强调，为了能够真正得益于用户的熟悉性、较短的开发时间以及用户界面的语义一致性等优点，你必须恰当地使用这些按钮和图标。具体来说，你使用按钮或图标时应当依据其文档说明中的含义和推荐位置，而不要根据你自己对其外观的解释。关于这些系统自带按钮和图标的含义及位置信息，参见“用于工具栏与导航栏的标准按钮”、“用于标签栏的标准图标”和“用于表格行及其他用户界面元素中的标准按钮”。

Interface Builder makes it easy to use the system-provided buttons and apply system-provided icons to your controls. See the appearance-related information in “iPhone OS Interface Objects” in Interface Builder User Guide for guidance.

Interface Builder 使得使用系统自带的按钮以及将系统自带的图标应用到你的控件上变得非常容易。相关指南，参见 Interface Builder User Guide 中的 “iPhone OS Interface Objects” 查阅与外观相关的信息。

If you can’t find a system-provided toolbar or navigation bar button or tab bar item icon that has the appropriate meaning for a specific function in your application, you should design a custom button or icon. “Icons for Navigation Bars, Toolbars, and Tab Bars” gives some guidelines to help you do this.

如果你找不到与你应用程序中的特定功能含义相当的系统自带工具栏或导航栏按钮或者标签栏图标，你则应当设计自定义按钮或图标。“用于导航栏、工具栏及标签栏的图标”提供了与此相关的设计准则。