XML Recommendation每
Attribute order is insignificant：
Note that the order of attribute specifications in a start-tag or
empty-element tag is not significant.
因此,XML Schema无法约束属性排序.
通常,XML建议都会认为属性排序无关紧要,但如果您的应用程序需要属性排序,请参阅XML Normalization Recommendation或Canonical XML Recommendation中的section on attribute processing.
