如何在ScalaFX中使用CSS设置自定义TreeCell的样式？

我想使用CSS更改自定义TreeCell的背景颜色，但在树单元上设置style属性不起作用。我可以用交替的黄色和灰色单元格为树设置样式，CSS文件如下所示：

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:even {
    -fx-background-color: yellow;
}

.tree-cell:odd {
    -fx-background-color: grey;
}

.tree-cell:drag-over {
    -fx-background-color: plum;
}

  onDragEntered = (event: DragEvent) => {
    val db = event.getDragboard
    if (db.hasContent(customFormat)) {
      textFill = Color.DEEPSKYBLUE

      style() = "tree-cell:drag-over"
    }

    event.consume()
  }

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:filled:even {
    -fx-background-color: lightyellow;
}

.tree-cell:filled:odd {
    -fx-background-color: lightsteelblue;
}

.tree-cell.drag-over:filled {
    -fx-background-color: plum;
}

import scala.collection.JavaConversions._

// Copy the list, so that it isn't modified in place.
var oldStyleClass: util.Collection[String] = styleClass.toList

onDragEntered = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.DEEPSKYBLUE

    // Remember the original style by taking a copy.
    oldStyleClass = styleClass.toList

    // Restyle filled cells with .tree-cell.dragover:filled
    // for the duration of the drag
    styleClass.add("drag-over")
  }

  event.consume()
}

onDragExited = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.BLACK
  }

  // Restore the original style.
  styleClass.setAll(oldStyleClass)

  event.consume()
}

并使用如下所示的事件处理程序更改文本的填充样式：

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:even {
    -fx-background-color: yellow;
}

.tree-cell:odd {
    -fx-background-color: grey;
}

.tree-cell:drag-over {
    -fx-background-color: plum;
}

  onDragEntered = (event: DragEvent) => {
    val db = event.getDragboard
    if (db.hasContent(customFormat)) {
      textFill = Color.DEEPSKYBLUE

      style() = "tree-cell:drag-over"
    }

    event.consume()
  }

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:filled:even {
    -fx-background-color: lightyellow;
}

.tree-cell:filled:odd {
    -fx-background-color: lightsteelblue;
}

.tree-cell.drag-over:filled {
    -fx-background-color: plum;
}

import scala.collection.JavaConversions._

// Copy the list, so that it isn't modified in place.
var oldStyleClass: util.Collection[String] = styleClass.toList

onDragEntered = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.DEEPSKYBLUE

    // Remember the original style by taking a copy.
    oldStyleClass = styleClass.toList

    // Restyle filled cells with .tree-cell.dragover:filled
    // for the duration of the drag
    styleClass.add("drag-over")
  }

  event.consume()
}

onDragExited = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.BLACK
  }

  // Restore the original style.
  styleClass.setAll(oldStyleClass)

  event.consume()
}

---

但是树细胞的样式没有改变。

我最终找到了我自己问题的答案。CSS文件现在如下所示：

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:even {
    -fx-background-color: yellow;
}

.tree-cell:odd {
    -fx-background-color: grey;
}

.tree-cell:drag-over {
    -fx-background-color: plum;
}

  onDragEntered = (event: DragEvent) => {
    val db = event.getDragboard
    if (db.hasContent(customFormat)) {
      textFill = Color.DEEPSKYBLUE

      style() = "tree-cell:drag-over"
    }

    event.consume()
  }

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:filled:even {
    -fx-background-color: lightyellow;
}

.tree-cell:filled:odd {
    -fx-background-color: lightsteelblue;
}

.tree-cell.drag-over:filled {
    -fx-background-color: plum;
}

import scala.collection.JavaConversions._

// Copy the list, so that it isn't modified in place.
var oldStyleClass: util.Collection[String] = styleClass.toList

onDragEntered = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.DEEPSKYBLUE

    // Remember the original style by taking a copy.
    oldStyleClass = styleClass.toList

    // Restyle filled cells with .tree-cell.dragover:filled
    // for the duration of the drag
    styleClass.add("drag-over")
  }

  event.consume()
}

onDragExited = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.BLACK
  }

  // Restore the original style.
  styleClass.setAll(oldStyleClass)

  event.consume()
}

现在，当我拖过一个充满的单元格时，我会得到一个李子色。空细胞保持白色。 为了达到这个目的，我需要理解“CSS特殊性”的规则，尽管最终有可能简化完成的CSS文件，使每个案例完全匹配一个选择器

ScalaFX代码现在如下所示：

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:even {
    -fx-background-color: yellow;
}

.tree-cell:odd {
    -fx-background-color: grey;
}

.tree-cell:drag-over {
    -fx-background-color: plum;
}

  onDragEntered = (event: DragEvent) => {
    val db = event.getDragboard
    if (db.hasContent(customFormat)) {
      textFill = Color.DEEPSKYBLUE

      style() = "tree-cell:drag-over"
    }

    event.consume()
  }

.tree-cell:disabled {
    -fx-padding: 3 3 3 3;
    -fx-background-color: white;
}

.tree-cell:selected {
    -fx-background-color: blue;
}

.tree-cell:filled:even {
    -fx-background-color: lightyellow;
}

.tree-cell:filled:odd {
    -fx-background-color: lightsteelblue;
}

.tree-cell.drag-over:filled {
    -fx-background-color: plum;
}

import scala.collection.JavaConversions._

// Copy the list, so that it isn't modified in place.
var oldStyleClass: util.Collection[String] = styleClass.toList

onDragEntered = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.DEEPSKYBLUE

    // Remember the original style by taking a copy.
    oldStyleClass = styleClass.toList

    // Restyle filled cells with .tree-cell.dragover:filled
    // for the duration of the drag
    styleClass.add("drag-over")
  }

  event.consume()
}

onDragExited = (event: DragEvent) => {
  val db = event.getDragboard
  if (db.hasContent(customFormat)) {
    textFill = Color.BLACK
  }

  // Restore the original style.
  styleClass.setAll(oldStyleClass)

  event.consume()
}

在途中的某个地方，我因为一次失败的跌落而失去了动画效果。否则我很高兴（但在ScalaFX的土地上有点孤独。）