The event handlers for the onfocus and onblur events are rendered as shown in Listing 22.

清单 22 显示了为 onfocus 和 onblur 事件呈现事件处理程序的方法。

When a UI component gains or loses the keyboard focus, it generates events that can be captured through the onfocus and onblur attributes.

当UI组件获得或丢失键盘焦点，它将生成可以通过onfocus和onblur属性捕获的事件。

In this case, the custom component has already added the onfocus and onblur attributes to the nested components during the processing of a previous request.

在这种情况下，自定义组件已经在处理前一个请求期间将onfocus和onblur属性添加到嵌套组件。

For a better understanding of the encoding methods, consider the example from Listing 22, which contains an input component that already has an onfocus attribute.

为了更好地理解编码方法，考虑清单22的示例，它包含一个已经拥有onfocus属性的输入组件。

Next, you'll see how to build a custom component that modifies the onfocus and onblur attributes of every nested component that contains (see Listing 14).

下面，您将看到如何构建自定义组件，它修改每个包含 的嵌套组件的 onfocus 和 onblur 属性（参见清单 14）。