android scala eclipse插件的searchView小部件中的过滤方法

Question

我在 android 中使用了 searchView 小部件，eclipse Scala 插件，我想在按下搜索按钮后更新我的列表，现在我的过滤方法实现中有一些错误

请给我一些提示，

这里是过滤方法：

 override def getFilter(): Filter = {
  new Filter() {

    protected override def publishResults(constraint: CharSequence, results: 
FilterResults) {
      books = results.values.asInstanceOf[List[BookMetadata]]
      ItemAdapter.this.notifyDataSetChanged()
    }

    protected override def performFiltering(constraint: CharSequence): FilterResults = {
      val filteredResults: List[BookMetadata] =   
 ListBuffer(books.asScala.toList.filter(b.startsWith(constraint.toString)): _*)
      val results = new FilterResults()
      results.values = filteredResults
      results
    }
  }
}

我这里有个错误：

books = results.values.asInstanceOf[List[BookMetadata]]

 error: Multiple markers at this 
line 
- reassignment to val 
- reassignment to val

b 的一个错误。 val filtersResults: List[BookMetadata] =
ListBuffer(books.asScala.toList.filter(b.startsWith(constraint.toString)): _*)

  not found: value 
  b

提前致谢！

Answer 1

改变

val books 

到

var books 

并且 改变

val filteredResults: List[BookMetadata] = ListBuffer(books.asScala.toList.filter(b.startsWith(constraint.toString)): _*)

到

val filteredResults: List[BookMetadata] = ListBuffer(books.asScala.toList.filter(b => b.startsWith(constraint.toString)): _*)

请看Use of def, val, and var in scala