XML创建-错误:重载的方法构造函数UnfixedAttribute带有替代项
将其放入XML属性会产生错误:XML创建-错误:重载的方法构造函数UnfixedAttribute带有替代项,xml,scala,Xml,Scala,将其放入XML属性会产生错误: scala> val count = 7 count: Int = 7 scala> val seven = new Size(7, Units.COUNT) seven: Size = 7.0 count scala>val x= :8:错误:重载的方法构造函数UnfixedAttribute带有替代项: (key:String,value:Option[Seq[scala.xml.Node]],next:scala.xml.MetaData)s
scala> val count = 7
count: Int = 7
scala> val seven = new Size(7, Units.COUNT)
seven: Size = 7.0 count
scala>val x=
:8:错误:重载的方法构造函数UnfixedAttribute带有替代项:
(key:String,value:Option[Seq[scala.xml.Node]],next:scala.xml.MetaData)scala.xml.unfixedattribute
(key:String,value:String,next:scala.xml.MetaData)scala.xml.unfixedattribute
(key:String,value:Seq[scala.xml.Node],next1:scala.xml.MetaData)scala.xml.unfixedattribute
无法应用于(java.lang.String、Int、scala.xml.MetaData)
val x=
XML属性的输入必须是字符串。整数和对象不会使用其toString方法自动转换为字符串。
例如,如果使用单位枚举定义大小类:
scala> val x = <element count={count}/>
<console>:8: error: overloaded method constructor UnprefixedAttribute with alternatives:
(key: String,value: Option[Seq[scala.xml.Node]],next: scala.xml.MetaData)scala.xml.UnprefixedAttribute <and>
(key: String,value: String,next: scala.xml.MetaData)scala.xml.UnprefixedAttribute <and>
(key: String,value: Seq[scala.xml.Node],next1: scala.xml.MetaData)scala.xml.UnprefixedAttribute
cannot be applied to (java.lang.String, Int, scala.xml.MetaData)
val x = <element count={count}/>
已创建大小为的实例:
scala> object Units extends Enumeration {
| type Units = Value
| val COUNT = Value("count")
| val LB = Value("pounds")
| val OZ = Value("ounces")
| val GRAM = Value("grams")
| val KG = Value("kilograms")
| val GAL = Value("gallons")
| val QT = Value("quarts")
| val PINT = Value("pints")
| val FL_OZ = Value("fluid ounces")
| val L = Value("liters")
| }
defined module Units
scala> class Size(val value: Double, val unit: Units.Units) {
| override def toString = value + " " + unit.toString
| }
defined class Size
然后尝试将您的大小放入XML属性中,仍然会出现错误:
scala> val count = 7
count: Int = 7
scala> val seven = new Size(7, Units.COUNT)
seven: Size = 7.0 count
scala>val x=
:10:错误:重载的方法构造函数UnfixedAttribute带有替代项:
(key:String,value:Option[Seq[scala.xml.Node]],next:scala.xml.MetaData)scala.xml.unfixedattribute
(key:String,value:String,next:scala.xml.MetaData)scala.xml.unfixedattribute
(key:String,value:Seq[scala.xml.Node],next1:scala.xml.MetaData)scala.xml.unfixedattribute
无法应用于(java.lang.String、Size、scala.xml.MetaData)
val x=
^
必须显式调用toString方法。这项工作:
scala> val x = <element size={seven}/>
<console>:10: error: overloaded method constructor UnprefixedAttribute with alternatives:
(key: String,value: Option[Seq[scala.xml.Node]],next: scala.xml.MetaData)scala.xml.UnprefixedAttribute <and>
(key: String,value: String,next: scala.xml.MetaData)scala.xml.UnprefixedAttribute <and>
(key: String,value: Seq[scala.xml.Node],next1: scala.xml.MetaData)scala.xml.UnprefixedAttribute
cannot be applied to (java.lang.String, Size, scala.xml.MetaData)
val x = <element size={seven}/>
^
scala>val x=
x:scala.xml.Elem=