Below is an example of a custom constraint named zipcode.
如下代码自定义了一个名为ZipCode的约束。
In the example in Listing 3, the zipCode element is not defined globally.
在清单3的例子中，zipCode元素不是全局定义的。
Observant readers might notice that the zipCode field is a normal text field.
细心的读者可能注意到zipCode是一个普通的文本字段。
应用推荐