ComboBox下拉列表

创建下拉列表

ComboBox<String> comboBox = new ComboBox<>();  
comboBox.getItems().addAll("str1","str2","str3","str4","str5");

设置可编辑相较于ChoiceBox的特点comboBox.setEditable(true);
设置提示文字comboBox.setPromptText("请输入");
设置占位符comboBox.setPlaceholder(new Label("无元素"));
设置可见行数comboBox.setVisibleRowCount(3);

选项改变监听事件

comboBox.getSelectionModel().selectedItemProperty().addListener((observable, oldValue, newValue) -> {  
    System.out.println(newValue);  
});

单击事件

comboBox.setOnAction(event -> {  
    System.out.println(comboBox.getValue());  
});

案例

实体类

class Student {  
    private String name;  
    private double score;  
    private String subject;  

    public Student(String name, double score, String subject) {  
        this.name = name;  
        this.score = score;  
        this.subject = subject;  
    }  

    public Student() {  
    }  

    public String getName() {  
        return name;  
    }  

    public void setName(String name) {  
        this.name = name;  
    }  

    public double getScore() {  
        return score;  
    }  

    public void setScore(double score) {  
        this.score = score;  
    }  

    public String getSubject() {  
        return subject;  
    }  

    public void setSubject(String subject) {  
        this.subject = subject;  
    }  

    @Override  
    public boolean equals(Object o) {  
        if (this == o) return true;  
        if (o == null || getClass() != o.getClass()) return false;  
        Student student = (Student) o;  
        return Double.compare(student.score, score) == 0 && Objects.equals(name, student.name) && Objects.equals(subject, student.subject);  
    }  

    @Override  
    public int hashCode() {  
        return Objects.hash(name, score, subject);  
    }  
}

创建泛型为Student的下拉列表并初始化一些数据

Student student1 = new Student("张三", 78, "语文");  
Student student2 = new Student("李四", 69, "数学");  
Student student3 = new Student("王五", 70, "英语");  
Student student4 = new Student("赵六", 49, "物理");  
Student student5 = new Student("钱七", 80, "化学");  
Student student6 = new Student("孙八", 99, "生物");  
Student student7 = new Student("周九", 59, "政治");  
Student student8 = new Student("吴十", 10, "历史");  
ComboBox<Student> comboBox = new ComboBox<>();  
comboBox.getItems().addAll(student1, student2, student3, student4, student5, student6, student7, student8);

数据处理

comboBox.setConverter(new StringConverter<Student>() {  
    @Override  
    public String toString(Student object) {  
        if (object == null) {  
            return "";  
        }  
        String value = object.getName() + ":" + object.getScore() + ":" + object.getSubject();  
        return value;  
    }  
    // 在输入框中输入文本按下回车键时，调用此方法  
    @Override  
    public Student fromString(String string) {  
        // 以:分隔每一项
        String[] strings = string.split("[:]");  
        Student student = new Student(strings[0], Integer.parseInt(strings[1]), strings[2]);  
        return student;  
    }  
});

# ComboBox下拉列表

# 案例

ComboBox下拉列表

案例