prefixing带有问号的号码表示要访问硬编码的属性，它是在一个风格的主题定义的样式属性，而不是

Prefixing the ID with a question mark indicates that you want to access a style attribute that's defined in a style theme, rather than hard-coding the attribute.

请参阅引用样式属性在这里：accessing-resources

See "Referencing Style Attributes" here: accessing-resources