Button won't work javafx - button

Question

I'm a total beginner in programming. I've been trying to create a simple program that gets two values from the user (two grades from 0 to 10) and returns the average between them. I've done it with Swing and JOptionPane but using javafx I got nothing. Here goes the code.
package fxcalcmedia;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class FXCalcMedia extends Application {
#Override
public void start(Stage stage) throws Exception {
Parent root =
FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
stage.setTitle("CALCULADORA DE MÉDIA");
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
package fxcalcmedia;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.text.Text;
public class FXMLDocumentController implements Initializable {
#FXML
private Label lblMedia;
private Button btnCalc;
private Text txtMedia;
private Text txtNota1;
private Text txtNota2;
#FXML
private void clicouBotao(ActionEvent event) {
double nota1 = Double.parseDouble(txtNota1.getText());
double nota2 = Double.parseDouble(txtNota2.getText());
double media = (nota1+nota2)/2;
txtMedia.setText(Double.toString(media));
}
#Override
public void initialize(URL url, ResourceBundle rb) {
}
}
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.text.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<AnchorPane id="AnchorPane" prefHeight="155.0" prefWidth="303.0"
xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1"
fx:controller="fxcalcmedia.FXMLDocumentController">
<children>
<Label fx:id="lblMedia" layoutX="30.0" layoutY="119.0"
text="Média" />
<Label layoutX="28.0" layoutY="33.0" text="Nota 1" />
<Label layoutX="28.0" layoutY="76.0" text="Nota 2" />
<Button fx:id="btnCalc" layoutX="212.0" layoutY="71.0"
mnemonicParsing="false" onAction="#clicouBotao" text="Calcular"
/>
<TextField fx:id="txtNota1" layoutX="90.0" layoutY="28.0"
prefHeight="25.0" prefWidth="78.0" />
<TextField fx:id="txtNota2" layoutX="90.0" layoutY="71.0"
prefHeight="25.0" prefWidth="78.0" />
<TextField fx:id="txtMedia" layoutX="90.0" layoutY="114.0"
onAction="#clicouBotao" prefHeight="25.0" prefWidth="78.0" />
</children>
</AnchorPane>
So... the window appears, I insert the grades but when I click on the button to get the average grade, nothing happens. I've tried a lot of things, I've searched a lot... I hope somebody can help. Thanks again.

Answer 1

You need to place #FXML annotation on each Node that have fx:id="" in fxml file. It is necessary for FXMLLoader to create correct instances and inject them to controller.
Another problem is components type in fxml file. In fxml you use TextField
<TextField fx:id="txtNota1" layoutX="90.0" layoutY="28.0"
prefHeight="25.0" prefWidth="78.0" />
<TextField fx:id="txtNota2" layoutX="90.0" layoutY="71.0"
prefHeight="25.0" prefWidth="78.0" />
<TextField fx:id="txtMedia" layoutX="90.0" layoutY="114.0"
onAction="#clicouBotao" prefHeight="25.0" prefWidth="78.0" />
but in cotntroller you use Text:
private Text txtMedia;
private Text txtNota1;
private Text txtNota2;
Solution:
#FXML
private Label lblMedia;
#FXML
private Button btnCalc;
#FXML
private TextField txtMedia;
#FXML
private TextField txtNota1;
#FXML
private TextField txtNota2;

Answer 2

As an extension to #MBec's answer. A very nice tool for creating GUIs for javaFX is JavaFX Scene Builder. It provides you with drag & drop functionality and also gives templates for each fxml file's Controller class.