Question

当我再次运行应用程序时，我试图将更改保存到表中。下面的代码允许用户编辑单元格并提交更改，但是当我再次运行应用程序时，不会保存更改。如何从表格单元格编辑中永久更改？代码如下。（来自oracle的网站）。我试过玩它但没有成功。

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellEditEvent;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;

public class TableViewSample extends Application {

    private final TableView<Person> table = new TableView<>();
    private final ObservableList<Person> data =
            FXCollections.observableArrayList(
            new Person("Jacob", "Smith", "jacob.smith@example.com"),
            new Person("Isabella", "Johnson", "isabella.johnson@example.com"),
            new Person("Ethan", "Williams", "ethan.williams@example.com"),
            new Person("Emma", "Jones", "emma.jones@example.com"),
            new Person("Michael", "Brown", "michael.brown@example.com"));
    final HBox hb = new HBox();

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) {
        Scene scene = new Scene(new Group());
        stage.setTitle("Table View Sample");
        stage.setWidth(450);
        stage.setHeight(550);

        final Label label = new Label("Address Book");
        label.setFont(new Font("Arial", 20));

        table.setEditable(true);

        TableColumn<Person, String> firstNameCol = 
            new TableColumn<>("First Name");
        firstNameCol.setMinWidth(100);
        firstNameCol.setCellValueFactory(
            new PropertyValueFactory<>("firstName"));

        firstNameCol.setCellFactory(TextFieldTableCell.<Person>forTableColumn());
        firstNameCol.setOnEditCommit(
            (CellEditEvent<Person, String> t) -> {
                ((Person) t.getTableView().getItems().get(
                        t.getTablePosition().getRow())
                        ).setFirstName(t.getNewValue());
        });


        TableColumn<Person, String> lastNameCol = 
            new TableColumn<>("Last Name");
        lastNameCol.setMinWidth(100);
        lastNameCol.setCellValueFactory(
            new PropertyValueFactory<>("lastName"));
       lastNameCol.setCellFactory(TextFieldTableCell.<Person>forTableColumn());
       lastNameCol.setOnEditCommit(
            (CellEditEvent<Person, String> t) -> {
                ((Person) t.getTableView().getItems().get(
                        t.getTablePosition().getRow())
                        ).setLastName(t.getNewValue());
        });

        TableColumn<Person, String> emailCol = new TableColumn<>("Email");
        emailCol.setMinWidth(200);
        emailCol.setCellValueFactory(
            new PropertyValueFactory<>("email"));
        emailCol.setCellFactory(TextFieldTableCell.<Person>forTableColumn());       
        emailCol.setOnEditCommit(
            (CellEditEvent<Person, String> t) -> {
                ((Person) t.getTableView().getItems().get(
                        t.getTablePosition().getRow())
                        ).setEmail(t.getNewValue());
        });

        table.setItems(data);
        table.getColumns().addAll(firstNameCol, lastNameCol, emailCol);

        final TextField addFirstName = new TextField();
        addFirstName.setPromptText("First Name");
        addFirstName.setMaxWidth(firstNameCol.getPrefWidth());
        final TextField addLastName = new TextField();
        addLastName.setMaxWidth(lastNameCol.getPrefWidth());
        addLastName.setPromptText("Last Name");
        final TextField addEmail = new TextField();
        addEmail.setMaxWidth(emailCol.getPrefWidth());
        addEmail.setPromptText("Email");

        final Button addButton = new Button("Add");
        addButton.setOnAction((ActionEvent e) -> {
            data.add(new Person(
                    addFirstName.getText(),
                    addLastName.getText(),
                    addEmail.getText()));
            addFirstName.clear();
            addLastName.clear();
            addEmail.clear();
        });

        hb.getChildren().addAll(addFirstName, addLastName, addEmail, addButton);
        hb.setSpacing(3);

        final VBox vbox = new VBox();
        vbox.setSpacing(5);
        vbox.setPadding(new Insets(10, 0, 0, 10));
        vbox.getChildren().addAll(label, table, hb);

        ((Group) scene.getRoot()).getChildren().addAll(vbox);

        stage.setScene(scene);
        stage.show();
    }

    public static class Person {

        private final SimpleStringProperty firstName;
        private final SimpleStringProperty lastName;
        private final SimpleStringProperty email;

        private Person(String fName, String lName, String email) {
            this.firstName = new SimpleStringProperty(fName);
            this.lastName = new SimpleStringProperty(lName);
            this.email = new SimpleStringProperty(email);
        }

        public String getFirstName() {
            return firstName.get();
        }

        public void setFirstName(String fName) {
            firstName.set(fName);
        }

        public String getLastName() {
            return lastName.get();
        }

        public void setLastName(String fName) {
            lastName.set(fName);
        }

        public String getEmail() {
            return email.get();
        }

        public void setEmail(String fName) {
            email.set(fName);
        }
    }
}

Answer 1

从评论中我了解到问题是如何从表中获取数据，因此您可以将其写入数据库。
表信息由ObservableList<Person> data表示。它总是反映实际的表格信息获取信息只需循环它。运行以下测试：

添加一个方法来打印一些表的数据：

private void printSomeTableData() {

    for(Person p : data) {

        System.out.println(p.getFirstName() + ", " + p.lastName.get()+ ", " +p.getEmail());
    }
}

在构造函数中添加一个按钮以使用此方法：

final Button printButton = new Button("Print");
printButton.setOnAction(e -> printSomeTableData());
//change 
// hb.getChildren().addAll(addFirstName, addLastName, addEmail, addButton);
//to
hb.getChildren().addAll(addFirstName, addLastName, addEmail, addButton, printButton);

每当您按“打印”更新表格数据打印出来。
我希望这个简单的测试可以使机制清晰。将TableView视为ObservableList<Person> data的图形表示。表信息的任何更改都会反映在data。

中

Answer 2

从评论我看到你不知道如何从文本字段中获取值...嗯，这很简单，尝试这样的事情：textFieldName.getText（），你将得到的值TextField :)

修改对于在TableView上进行迭代，请执行以下操作：

for (Person person : table.getItems()){ writeToDatabase(person.getFirstName());}

如何从表格单元格编辑中永久更改？

2 个答案: