將double值綁定到JavaFX gui

Question

盡管我無法將計算出的頻率傳遞給GUI，但我已經為學校的項目（調諧器）實施了fft。 我嘗試了綁定，關鍵幀，但我似乎無法掌握它，這對Java真的很新。

public class FrequencyBean {

double freq;
private SimpleDoubleProperty value = new SimpleDoubleProperty(this, "value");


public void setValue(double value){
        this.value.set(value);
        System.out.println(value+" set");
    }
public DoubleProperty getDoublePropertyValue(){
    System.out.println("gotvals");
    return value;
}
public FrequencyBean(){
    freq = 10.0;
}

這是我控制器的一部分，我也被推薦使用一種叫做緊密綁定的東西，這將是該類的抽象。 這樣對我的代碼好嗎？

這是我的主控制器：

public class Controller implements Initializable{

FrequencyBean fbean;

@FXML
private Label otherFq;

@FXML
private Text frequency;

@FXML
private Text sharpFq;

@FXML
private Rectangle sharp6;

@FXML
private Text flatFq;

@FXML
private Rectangle center_rectangle;

@FXML
private Rectangle sharp1;

@FXML
private Rectangle sharp2;

@FXML
private Rectangle sharp3;

@FXML
private Rectangle sharp4;

@FXML
private Rectangle sharp5;

@FXML
private Text centerFq;

@FXML
private Rectangle flat6;

@FXML
private Rectangle flat5;

@FXML
private Rectangle flat4;

@FXML
private Rectangle flat3;

@FXML
private Rectangle flat2;

@FXML
private Rectangle flat1;

@Override
public void initialize(URL location, ResourceBundle resources) {

    fbean = new FrequencyBean();
    otherFq = new Label();
    frequency = new Text();
    boolean stop = false;
    InputThread input =  new InputThread();
         Task<Void> in = new Task<Void>() {

            @Override
            protected Void call() throws Exception {

                input.run();

                return null;

                }
            };
        Thread th0 = new Thread(in);
        th0.start();


        frequency.textProperty().bind(fbean.getDoublePropertyValue());
}

Answer 1

正確地將FrequencyBean重寫為“ JavaFX-Bean”：

public class FrequencyBean {

   private SimpleDoubleProperty frequency = new SimpleDoubleProperty();

   /**
   * @param frequency the frequency to set
   */
   public void setFrequency(double value){
        this.frequency.set(value);
   }

   /**
   * @return the frequency as double 
   */
   public double getFrequency(){
        return this.frequency.get();
   }

   /**
   * @return the frequency property
   */
   public DoubleProperty frequencyProperty(){
      return value;
   }
   public FrequencyBean(){
      frequency = 10.0;
   }
}

正如Jame_D指出的那樣：不要初始化帶有@FXML注釋的控件。 像這樣綁定有問題的控件：

...
@FXML 
TextField tf_Frequency;
...

fbean = new FrequencyBean(20.3);
tfFrequency.textProperty().bind(fbean.frequencyProperty().asString("%.2f"));

請注意，如果您需要單向綁定，這是正確的。 還有一個bindBidirectional方法。