您好，我想创建一个javafx TextField，用户只能在当前订单中输入A11111111A [英] Hello , I want to create a javafx TextField where the user can only input in the current order A11111111A

问题描述

所以第一个和最后一个输入应该是字母，它们之间应该只是数字。这是我的代码：

So the first and last input should be letters, and between them should be only numbers. Here is my code :

tf.textProperty().addListener(new ChangeListener<String>() {
        public void changed(final ObservableValue<? extends String> ov, final String oldValue, final String newValue) {

            String text_of_first_letter = tf.getText().substring(0, 1);
            if (tf.getText().length() > 1 ) {

                if(!newValue.matches("\\d*")) {

                    tf.setText(newValue.replaceFirst("[^\\d]", ""));
                }

            }
            else if(tf.getText().length() == 1){
                System.out.println("ktu");
                tf.setText(newValue.replaceFirst("[^\\d]", text_of_first_letter));
            }
        }
    });

推荐答案

您可以使用 TextFormatter 和字符串的 匹配。

如果 TextField 中的文字不符合这三个正则表达式中的一个，然后显示旧文本。

If the text in the TextField does not meet one of these three Regex, then show the old text.

case 1: newVal.matches("[A-z]") -> Single alpha character
case 2: newVal.matches("[A-z]\\d+") -> Alpha character followed by digits
case 3: newVal.matches("[A-z]\\d+[A-z]") -> Alpa character followed by digits than another alpha character.

完整应用

Full app

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.control.TextFormatter;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

/**
 *
 * @author blj0011
 */
public class JavaFXApplication149 extends Application
{

    @Override
    public void start(Stage primaryStage)
    {
        TextField textField = new TextField();
        textField.setTextFormatter(new TextFormatter<>(c
                -> {
            if (c.getControlNewText().isEmpty()) {
                return c;
            }

            if (c.getControlNewText().matches("[A-z]") || c.getControlNewText().matches("[A-z]\\d+") || c.getControlNewText().matches("[A-z]\\d+[A-z]")) {
                return c;
            }
            else {
                return null;
            }

        }));



        StackPane root = new StackPane(textField);
        Scene scene = new Scene(root, 300, 250);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        launch(args);
    }

}

**更新：更改为的TextFormatter 。 @kleopatra说这是实现这一目标的正确方法。

**Update: Change to TextFormatter. @kleopatra said it's the correct way to achieve this.

这篇关于您好，我想创建一个javafx TextField，用户只能在当前订单中输入A11111111A的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！