Vaadin Grid setColumn（） - 将成员对象的字段设置为列

Question

假设我有以下情况：

有两个实体：

public class Address {

  private City city;
  private String street;

  public String getStreet() {
    return street;
  }

  public void setStreet(String street) {
    this.street = street;
  }

  public City getCity() {
    return city;
  }

  public void setCity(City city) {
    this.city = city;
  }
}

和

public class City {

  private String name;

  public String getName() {
    return name;
  }

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

我想使用BeanItemContainer在网格组件上显示街道和城市名称，我应该如何指定列名？

P尝试使用＆＃34; street＆＃34;和＆＃34; city.name＆＃34;，但它会引发异常。

java.lang.IllegalStateException: Found at least one column in Grid that does not exist in the given container: city.name with the header "Name". Call removeAllColumns() before setContainerDataSource() if you want to reconfigure the columns based on the new container.

Answer 1

您没有显示与网格相关的代码，但是您可以在下面看到至少2种方法（请注意，为方便起见，我为您的对象创建了一些构造函数）：

<强>代码：

public class MyUi extends UI {
    @Override
    protected void init(VaadinRequest request) {
        // basic stuff
        Layout content = new VerticalLayout();
        content.setSizeFull();
        setContent(content);

        // container & grid
        BeanItemContainer<Address> container = new BeanItemContainer<>(Address.class);
        Grid grid = new Grid(container);

        // 1) either manually add nested properties and hide the actual inner bean
        container.addNestedContainerProperty("city.name");
        grid.getColumn("city.name").setHeaderCaption("City");
        grid.setColumns("street", "city.name"); // hide bean column

        // 2) or make the container create nested properties for your inner beans
        container.addNestedContainerBean("city");
        grid.getColumn("city.name").setHeaderCaption("City");

        // create some dummy data to populate the grid
        City city = new City("There");
        Address address = new Address(city, "Here");
        container.addItem(address);
        content.addComponent(grid);
    }
}

<强>结果：