JavaFX TableView行已添加但不可见 [英] JavaFX TableView row added but not visible
问题描述
我有一个TableView，要用来自某些TextField的数据填充，为此，我复制了另一个自另一个TableView的代码，因为它一直在工作.但是在第二个TableView中，数据未在表中显示为行.我知道已添加数据，因为我可以使用键盘上的箭头键在各行之间切换，并且在调试器模式下，每次添加行时都会更新items属性.在另一个TableView中，代码可以正常工作，但在第二个上却无法正常工作，有关如何解决此问题的任何想法?我读了其他有关PropertyValueFactory的问题，但事实是，第一个示例有效，而第二个示例无效.我尝试更改变量的名称，但仍然看不到.
I have a TableView that I want to populate with data from some TextFields, to do this, I copied code from one other TableView I have in my aplication since it was working. But in this second TableView, the data is not being shown as rows in the table. I know the data was added because I can switch between the rows using the arrow keys on the keyboard, and in the debugger mode, the items property is updated every time I add the rows. In the other TableView the code is working properly but not on the second, any ideas on how to fix this? I read the other questions talking about the PropertyValueFactory, but the thing is, the first example works and the second one doesn't. I tried changing the name of the variables but still had no look.
存储数据的类:
public class Produto {
private String nome, codigo;
private double preco, precoCompra;
private int quantidade;
public String getNome(){return nome;}
public String getCodigo(){return codigo;}
public double getPreco(){return preco;}
public int getQuantidade(){return quantidade;}
public double getPrecoCompra(){return precoCompra;}
public Produto (int quantidade, String nome) {
this.quantidade = quantidade;
this.nome = nome;
}
public Produto(String nome, String codigo, double preco, double precoCompra) {
this.nome = nome;
this.codigo = codigo;
this.preco = preco;
this.precoCompra = precoCompra;
}
public Produto(String nome, String codigo, double preco, double precoCompra, int quantidade) {
this.nome = nome;
this.codigo = codigo;
this.preco = preco;
this.precoCompra = precoCompra;
this.quantidade = quantidade;
}
public Produto(String nome, int quantidade){
this.nome = nome;
this.quantidade = quantidade;
}
}
TableView 1中的工作代码:
Working code from TableView 1:
控制器:
public class VerEstoque {
@FXML
BorderPane root;
@FXML
StackPane rootVE;
@FXML
private TableView tabela = new TableView();
private TableColumn<Produto, String> codigo = new TableColumn<>("CODIGO");
private TableColumn<Produto, String> nome = new TableColumn<>("NOME");
private TableColumn<Produto, Double> preco = new TableColumn<>("PREÇO DE VENDA");
private TableColumn<Produto, Double> precoCompra = new TableColumn<>("PREÇO DE COMPRA");
private TableColumn<Produto, Integer> quantidade = new TableColumn<>("QUANTIDADE");
private static ArrayList<Produto> produtos = new ArrayList<>();
private static ObservableList<Produto> listaProdutos = FXCollections.observableArrayList();
@FXML
private void initialize() {
Main.roots.add(rootVE);
tabela.getColumns().addAll(codigo, nome, preco, precoCompra, quantidade);
codigo.setCellValueFactory(new PropertyValueFactory<>("codigo"));
nome.setCellValueFactory(new PropertyValueFactory<>("nome"));
preco.setCellValueFactory(new PropertyValueFactory<>("preco"));
precoCompra.setCellValueFactory(new PropertyValueFactory<>("precoCompra"));
quantidade.setCellValueFactory(new PropertyValueFactory<>("quantidade"));
tabela.setItems(listaProdutos);
tabela.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
buscarEstoque();
}
static void buscarEstoque() {
//In this case the data is being pulled from a database and added to an arraylist
BancoDeDados bd = BancoDeDados.getInstance();
try {
ResultSet rs = bd.select("SELECT * FROM Estoque");
while (rs.next()) {
produtos.add(new Produto(rs.getString("Nome"), rs.getString("Codigo"), rs.getDouble("PrecoVenda"), rs.getDouble("PrecoCompra") , rs.getInt("Quantidade")));
}
rs.close();
listaProdutos.clear();
listaProdutos.addAll(produtos);
produtos.clear();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
FXML文件:
<StackPane xmlns="http://javafx.com/javafx" xmlns:fx="http://javafx.com/fxml" fx:id="rootVE"
prefHeight="400.0" prefWidth="600.0" fx:controller="mercado.controllers.VerEstoque">
<BorderPane prefHeight="400.0" prefWidth="600.0" fx:id="root">
<top>
<HBox alignment="CENTER">
<children>
<Label text="ESTOQUE" fx:id="titulo"/>
</children>
</HBox>
</top>
<center>
<TableView fx:id="tabela"/>
</center>
</BorderPane>
上面的代码按预期工作，但是下面的代码中有错误:
The above code works as intended but I have errors in the code below:
控制器:
public class DefinirProdutos {
@FXML private StackPane rootDP;
@FXML private VBox base;
@FXML private TextField campoQtd, campoNome;
@FXML private TableView tabela;
private TableColumn<Produto, Integer> qtd = new TableColumn<>("Qtd");
private TableColumn<Produto, String> nome = new TableColumn<>("Produto");
private ArrayList<Produto> arrayProdutos = new ArrayList<>();
private ObservableList<Produto> listaProdutos = FXCollections.observableArrayList();
@FXML
private void initialize() {
tabela.getColumns().addAll(qtd, nome);
tabela.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
campoNome.setPromptText("Produto");
campoQtd.setPromptText("Qtd");
nome.setCellValueFactory(new PropertyValueFactory<>("produto"));
qtd.setCellValueFactory(new PropertyValueFactory<>("qtd"));
tabela.setItems(listaProdutos);
}
@FXML
private void adicionarProduto() {
int valorQtd = campoQtd.getText().length();
int valorNome = campoNome.getText().length();
if(valorQtd == 0 && valorNome == 0){
//warn that the textfields are empty, irrelevant
}else if(valorQtd == 0){
//warn that the textfield is empty
}else if(valorNome == 0){
//warn that the textfield is empty
}else{
//Codigo pra caso nao estiver adicionado na array
arrayProdutos.add(new Produto(Integer.parseInt(campoQtd.getText()), campoNome.getText()));
listaProdutos.clear();
listaProdutos.addAll(arrayProdutos);
tabela.refresh();
}
}
}
未显示的表格视图的FXML:
FXML for the tableview that does not show:
<StackPane xmlns="http://javafx.com/javafx" xmlns:fx="http://javafx.com/fxml" prefHeight="600.0"
maxWidth="800.0" fx:id="rootDP"
fx:controller="mercado.controllers.DefinirProdutos">
<VBox fx:id="base" spacing="30">
<children>
<HBox alignment="CENTER">
<children>
<Label text="DEFINIR PRODUTOS" fx:id="titulo"/>
</children>
</HBox>
<HBox alignment="CENTER" spacing="10">
<children>
<TextField fx:id="campoQtd" alignment="CENTER"/>
<TextField alignment="CENTER" fx:id="campoNome"/>
<Button text="Adicionar" prefWidth="140" prefHeight="40" fx:id="btnAdd"
onAction="#adicionarProduto"/>
</children>
</HBox>
<TableView fx:id="tabela"/>
<HBox alignment="CENTER" fx:id="confirmar">
<children>
<Button text="Feito" prefWidth="200" prefHeight="40" fx:id="btnFeito"/>
</children>
</HBox>
</children>
</VBox>
</StackPane>
推荐答案
反射通常是完成任务的最糟糕的方法，这就是原因之一.
Reflection is usually the worst possible way to accomplish a task, and this is one of the reasons.
使用反射时，编译器无法检查您是否为类，方法，字段或bean属性使用了错误或拼写错误的名称.在这种情况下，编译器无法检查您传递给PropertyValueFactory构造函数的参数是否有效.
When you use reflection, the compiler cannot check whether you’ve used an incorrect or misspelled name for a class, method, field, or bean property. In this case, the compiler cannot check whether the argument you pass to a PropertyValueFactory constructor is valid.
更好的方法是避免完全使用PropertyValueFactory，而是为每个TableColumn编写自己的单元格值工厂:
A better approach is to avoid using PropertyValueFactory entirely, and instead write your own cell value factory for each TableColumn:
codigo.setCellValueFactory(
f -> new SimpleStringProperty(f.getValue().getCodigo()));
nome.setCellValueFactory(
f -> new SimpleStringProperty(f.getValue().getNome()));
preco.setCellValueFactory(
f -> new SimpleDoubleProperty(f.getValue().getPreco()));
precoCompra.setCellValueFactory(
f -> new SimpleDoubleProperty(f.getValue().getPrecoCompra()));
quantidade.setCellValueFactory(
f -> new SimpleIntegerProperty(f.getValue().getQuantidade()));
如果我们对DefinirProdutos类中的TableColumns做类似的更改:
If we make a similar change to your TableColumns in the DefinirProdutos class:
nome.setCellValueFactory(
f -> new SimpleStringProperty(f.getValue().getProduto()));
qtd.setCellValueFactory(
f -> new SimpleIntegerProperty(f.getValue().getQtd()));
编译器会帮助您通知那些方法不存在.
the compiler will helpfully inform you that those methods do not exist.
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