Catch value of Spinner JavaFX

Question

I'm trying to get value of Spinner(JavaFX). But return null.

Source:

    public class FXMLTeste implements Initializable {
        @FXML 
            private Spinner uni;

        @Override
        public void initialize(URL url, ResourceBundle rb) {       
            uni.setEditable(true);
        }  
        @FXML
        public void actionButton(){
            System.out.println(uni.getValue()); // return NULL
        }
}

fxml

<Spinner fx:id="uni" prefHeight="25.0" prefWidth="342.0"></Spinner>

score 1 · Accepted Answer · edited May 23 '17 at 12:31

You need to set the valueFactory for the spinner to allow the Spinner's value to become non-null. This can be done by directly assigning the property:

<Spinner fx:id="uni" prefHeight="25.0" prefWidth="342.0">
    <valueFactory>
        <!-- add factory instance creation here -->
    </valueFactory>
</Spinner>

by using the appropriate constructor

<Spinner fx:id="uni" prefHeight="25.0" prefWidth="342.0" min="1" max="10" initialValue="4" />

or by "manually" doing it in the initialize method:

SpinnerValueFactory valueFactory = ...
uni.setValueFactory(valueFactory);

Also you should specify the type parameter for the Spinner, even if it's a wildcard (Spinner<?>), see What is a raw type and why shouldn't we use it?

Making an educated guess, you may be looking for something like this:

<fx:define>
    <FXCollections fx:factory="observableArrayList" fx:id="unis" /> 
</fx:define>
<Spinner fx:id="uni" prefHeight="25.0" prefWidth="342.0" items="$unis" />

Controller

@FXML
private Spinner<String> uni;

@FXML
private ObservableList<String> unis;

@Override
public void initialize(URL url, ResourceBundle rb) {
    unis.add("Oxford");
    unis.add("Harvard");
}

Catch value of Spinner JavaFX

fxml

1 Answers1