zoukankan html css js c++ java

Scala界面事件处理

演示样例代码：

import scala.swing.SimpleSwingApplication
import scala.swing.MainFrame
import scala.swing.Button
import scala.swing.Label
import scala.swing.Orientation
import scala.swing.BoxPanel
import scala.swing.Swing
import scala.swing.event.ButtonClicked

object GUI_Panel_Layout extends SimpleSwingApplication{
  def top = new MainFrame{
    title = "Second GUI"
    val button = new Button{
      text = "Scala"
    }
    val label = new Label {
      text = "Here is Spark!!"
    }
    
    contents = new BoxPanel(Orientation.Vertical){
      contents += button
      contents += label
      border = Swing.EmptyBorder(50,50,50,50)
    }
    
    listenTo(button) //监听该button
    var clicks = 0
    reactions += {
      case ButtonClicked(button) => {
        clicks += 1
        label.text = "Clicked " + clicks + "times"
      }
    }
  }

执行效果（监听button点击次数）：

==========================================================

演示样例代码二：

import scala.swing.SimpleSwingApplication
import scala.swing.FileChooser
import java.io.File
import scala.swing.MainFrame
import scala.swing.FlowPanel
import scala.swing.Button
import scala.swing.Label
import scala.swing.event.ButtonClicked


object GUI_Event extends SimpleSwingApplication {
  
  val fileChooser = new FileChooser(new File(".")) //文件对话框
  fileChooser.title = "File Chooser"
  val button = new Button{
    text = "Choose a File from local"
  }
  val label = new Label {
    text = "No any file selected yet."
  }
  val mainPanel = new FlowPanel{
    contents += button
    contents += label
  }
  
  def top = new MainFrame{
    title = "Scala GUI Programing advanced By LEAF !!!"
    contents = mainPanel
    
    listenTo(button)
    
    reactions += {
      case ButtonClicked(b) => {
        val result = fileChooser.showOpenDialog(mainPanel)
        if(result == FileChooser.Result.Approve){
          label.text = fileChooser.selectedFile.getPath()
        }
      }
    }
  }
  
}

执行效果：

当点击choose a file from local时。我们能够得到当前文件系统，如图：

当我们选择某一个文件时。label中监听该文件的绝对路径(比方我们选择.class文件)：

相关来源：DT大数据梦工厂，微信公众号是DT_Spark，每天都会有大数据实战视频公布，请您持续学习。