简单的JavaFX HelloWorld不起作用 [英] Simple JavaFX HelloWorld Does Not Work

问题描述

我仍然一遍又一遍地得到这个错误：解析onAction ='＃sayHelloWorld'时出错，要么事件处理程序不在命名空间中，要么脚本中有错误。。我已经在互联网上搜索了一个解决方案，但没有任何作用，当然我是一个小细节，因为我是JAvaFX的新手，这是我的第一个HelloWorld应用程序。无论如何，这是我正在使用的代码：

I am still getting this error over and over again: Error resolving onAction='#sayHelloWorld', either the event handler is not in the Namespace or there is an error in the script.. I've googled in the Internet for a solution but nothing works, surely is a small detail somrwhere I'm missing since I'm new to JAvaFX, this is my first HelloWorld app. Anyways, this is the code I'm using:

sample.fxml：

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>

<GridPane alignment="center" hgap="10" vgap="10" xmlns="http://javafx.com/javafx/8"
          xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.SampleController">
    <columnConstraints>
        <ColumnConstraints />
        <ColumnConstraints />
    </columnConstraints>
    <rowConstraints>
        <RowConstraints />
        <RowConstraints />
    </rowConstraints>
   <children>
       <Button text="Load News"
               GridPane.columnIndex="1" GridPane.rowIndex="1"
               onAction="#sayHelloWorld"/>
       <Label GridPane.columnIndex="0" GridPane.rowIndex="1" fx:id="helloWorld"/>
   </children>
</GridPane>

和 SampleController.java

package sample;

import javafx.scene.control.Label;

import java.awt.event.ActionEvent;

public class SampleController {
    public Label helloWorld;

    public void sayHelloWorld(ActionEvent actionEvent) {
    }
}

任何帮助都将不胜感激。

Any help would be appreciated.

推荐答案

发现问题。它是ActionEvent类，在import部分中声明的类不是JavaFX类，因此使用正确的类使其工作。这是最终代码：

Found the problem. It was the ActionEvent class, the class declared in the import section is not a JavaFX class, so using the correct one makes it work. This is the final code:

package sample;

//import java.awt.event.ActionEvent;  //This was the error!
import javafx.event.ActionEvent;
import javafx.scene.control.Label;

public class SampleController {
    public Label helloWorld;

    public void sayHelloWorld(ActionEvent actionEvent) {
        helloWorld.setText("Hello World!!");
    }
}

无需注释。

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