FXML：绑定到嵌套字段 [英] FXML: Bind to nested field

问题描述

我有 TableColumn 编码为：

<TableColumn text="Nom" prefWidth="${purchasesTable.width*0.65}">
    <cellValueFactory>
        <PropertyValueFactory property="item.name" />
    </cellValueFactory>
</TableColumn>

它的 TableView 的items属性被绑定到购买类列表：

it's TableView's items property is bound to a list of Purchase class:

购买类：

public class Purchase {

private Item item;


public Item getItem() {
    return item;
}

public void setItem(Item item) {
    this.item = item;
}

}

我的 Item 类如下：

public class Item {
private long id;
private StringProperty name = new SimpleStringProperty();
private DoubleProperty price = new SimpleDoubleProperty();

//Getters and Setters
public long getId() {
    return id;
}
public void setId(long id) {
    this.id = id;
}

public final StringProperty nameProperty() {
    return this.name;
}


public final String getName() {
    return this.nameProperty().get();
}


public final void setName(final String name) {
    this.nameProperty().set(name);
}

}

当我将购买添加到我的表时，名称单元格不会出现。我究竟做错了什么？我的 Item 字段是否需要作为属性，因为我想在不使用JavaFX的其他地方使用它们？

when I add Purchases to my table the name cell do not appear. What am I doing wrong? and is it necessary to my Item fields as properties, because I want to use them somewhere else where JavaFX is not used?

推荐答案

PropertyValueFactory 不支持属性属性。你需要在这里自己实现 Callback ，这必须在控制器类中完成：

PropertyValueFactory does not support "properties of properties". You need to implement the Callback yourself here, which has to be done in the controller class:

public class MyController {

    @FXML
    private TableColumn<Purchase, String> nameColumn ;

    public void initialize() {
        nameColumn.setCellValueFactory(cellData -> {
            String name ;
            Purchase purchase = cellData.getValue(); 
            if (purchase == null) {
                name = null ;
            } else {
                name = purchase.getName();
            }
            return new SimpleStringProperty(name);
        });
        // ...
    }

    // ...
}

然后在fxml中，你需要将表格列映射到控制器中的字段

and then in the fxml, of course, you need to map the table column to the field in the controller

<TableColumn fx:id="nameColumn" text="Nom" prefWidth="${purchasesTable.width*0.65}" />

这篇关于FXML：绑定到嵌套字段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！