将这个问题减少到最低限度，考虑这个MarkupExtension类......publicclassProblemStatement:MarkupExtension{privatereadonlystring_first;privatereadonlystring_second;publicProblemStatement(stringfirst,stringsecond){_first=first;_second=second;}publicoverrideobjectProvideValue(IServiceProviderserviceProvider){returnthis;}