将decimal转换为各种数据类型时，在textfield中获取错误

Question

GridPane paneForVBoxes = new GridPane();
        paneForVBoxes.setPadding(new Insets(10, 10, 10, 10));
        paneForVBoxes.setVgap(10);
        paneForVBoxes.setHgap(10);

        VBox units = new VBox(12);
        units.setAlignment(Pos.CENTER_LEFT);
        Label lbDec = new Label("Decimal");
        Label lbHex = new Label("Hex");
        Label lbBin = new Label("Binary");
        units.getChildren().addAll(lbDec, lbHex, lbBin);


        VBox textFields = new VBox(5);
        TextField tfDec = new TextField();
            tfDec.setPrefColumnCount(19);
            tfDec.setAlignment(Pos.CENTER_RIGHT);
        TextField tfHex = new TextField();
            tfHex.setPrefColumnCount(19);
            tfHex.setAlignment(Pos.CENTER_RIGHT);
        TextField tfBin = new TextField();
            tfBin.setPrefColumnCount(19);
            tfBin.setAlignment(Pos.CENTER_RIGHT);

        textFields.getChildren().addAll(tfDec, tfHex, tfBin);

        paneForVBoxes.add(units, 0, 0);
        paneForVBoxes.add(textFields, 1, 0);

我在一定程度上实现了这一点，但当我删除textfields中的所有字符时，我会收到NumberFormatExceptions，我不知道如何解决这个问题。这是我试图修复的问题：请注意，这只是十进制到二进制字段的编码，通过对此进行简单的修复，我可以将其应用到其余尚未开发的代码中。注意：我还在tfdec.settext（“0”）内部和周围尝试了integer.parseint(s)；，但eclipse确实不喜欢这样做

 tfDec.setOnKeyReleased(e -> {
                if (tfDec.equals("")) {
                    tfDec.setText("0");
                }
                else {
                    String bin = Integer.toBinaryString(Integer.parseInt(tfDec.getText()));
                    tfBin.setText(bin);
                }
            });

/完整代码/

    package application;

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;


public class Elias16_5 extends Application {
    @Override
    public void start(Stage primaryStage) {
        try {
            GridPane paneForVBoxes = new GridPane();
            paneForVBoxes.setPadding(new Insets(10, 10, 10, 10));
            paneForVBoxes.setVgap(10);
            paneForVBoxes.setHgap(10);

            VBox units = new VBox(12);
            units.setAlignment(Pos.CENTER_LEFT);
            Label lbDec = new Label("Decimal");
            Label lbHex = new Label("Hex");
            Label lbBin = new Label("Binary");
            units.getChildren().addAll(lbDec, lbHex, lbBin);


            VBox textFields = new VBox(5);
            TextField tfDec = new TextField();
                tfDec.setPrefColumnCount(19);
                tfDec.setAlignment(Pos.CENTER_RIGHT);
            TextField tfHex = new TextField();
                tfHex.setPrefColumnCount(19);
                tfHex.setAlignment(Pos.CENTER_RIGHT);
            TextField tfBin = new TextField();
                tfBin.setPrefColumnCount(19);
                tfBin.setAlignment(Pos.CENTER_RIGHT);

            textFields.getChildren().addAll(tfDec, tfHex, tfBin);

            paneForVBoxes.add(units, 0, 0);
            paneForVBoxes.add(textFields, 1, 0);

            tfDec.setOnKeyReleased(e -> {
                if (tfDec.equals("")) {
                    tfDec.setText("0");
                }
                else {
                    String bin = Integer.toBinaryString(Integer.parseInt(tfDec.getText()));
                    tfBin.setText(bin);
                }
            });







            Scene scene = new Scene(paneForVBoxes, 300, 100);
            scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
            primaryStage.setTitle("Data Conversion");
            primaryStage.setScene(scene);
            primaryStage.show();
        } catch(Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}

Answer 1

你应该试试stringutils。所以这段代码：

if (tfDec.equals("")) {

将是

if (StringUtils.isBlank(tfDec.getText())) {

在这里阅读更多：stringutils.isblank（）vs string.isempty（）

tfDec.getText().equals("")

tfDec.equals("")