我有一个需要在组合框上呈现的名称的雇员列表供用户选择.以下代码在下拉列表中显示名称,但是当我选择一个名称时,组合显示的文本包含完整的POJO身份,一个字符串,如“src.org.entities.Employee@449ac7ce”
cboEmployees.setCellFactory(new Callback<ListView<Employee>,ListCell<Employee>>()
{
@Override
public ListCell<Employee> call(ListView<Employee> p)
{
return new ListCell<Employee>()
{
@Override
protected void updateItem(Employee item,boolean empty) {
super.updateItem(item,empty);
if (item != null)
{
setText(item.getName());
}
}
};
}
});
有没有办法使显示的文本渲染所选的名称,而不覆盖POJO的toString()方法？
解决方法
在您的ComboBox上调用
setButtonCell,提供适当的ListCell渲染器实现来显示员工名称.
例如：
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.stage.Stage;
import javafx.util.Callback;
public class BasicComboBoxSample extends Application {
public static void main(String[] args) { launch(args); }
@Override public void start(Stage stage) {
final Employee john = new Employee("John");
final Employee jill = new Employee("Jill");
final Employee jack = new Employee("Jack");
final ComboBox<Employee> cboEmployees = new ComboBox();
cboEmployees.setButtonCell(new EmployeeListCell());
cboEmployees.setCellFactory(new Callback<ListView<Employee>,ListCell<Employee>>() {
@Override public ListCell<Employee> call(ListView<Employee> p) {
return new EmployeeListCell();
}
});
cboEmployees.getItems().addAll(john,jill,jack);
cboEmployees.setValue(jill);
final StackPane layout = new StackPane();
layout.getChildren().add(cboEmployees);
layout.setStyle("-fx-background-color: cornsilk; -fx-padding: 15;");
stage.setScene(new Scene(layout));
stage.show();
}
class Employee {
public Employee(String name) { this.name = name; }
private String name;
public String getName() { return name; }
}
class EmployeeListCell extends ListCell<Employee> {
@Override protected void updateItem(Employee item,boolean empty) {
super.updateItem(item,empty);
if (item != null) {
setText(item.getName());
}
}
}
}
样品输出：