如何在javafx中从表中获取数据
我试图使用for循环从我的表中获取数据,但出现了null点异常。这是我的密码如何在javafx中从表中获取数据,javafx,javafx-8,Javafx,Javafx 8,我试图使用for循环从我的表中获取数据,但出现了null点异常。这是我的密码 for (int i = 0; i < tabel_otapproclInfo.getItems().size(); i++) { String s = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEEID(); String s2 = tabel_otapproclInfo.
for (int i = 0; i < tabel_otapproclInfo.getItems().size(); i++) {
String s = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEEID();
String s2 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEENAME();
String s3 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getEMPLOYEEDEPT();
String s4 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getSTATUS();
String s5 = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getDATES();
String u = tabel_otapproclInfo.getSelectionModel().getSelectedItem().getUSERNMAE();
System.out.println(u + " " + s + " " + s2 + " " + s3 + " " + s4 + " " + s5);
}
如果要循环查看
表中的所有数据,应采用这种方法。在本例中,表
对象是人
for (int i = 0; i < table.getItems().size(); i++)
{
Person tempPerson = table.getItems().get(i);
System.out.println(tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());
}
如果您想在选择后获取人物
,请使用侦听器
table.getSelectionModel().selectedItemProperty().addListener((obs, oldSelection, newSelection) -> {
System.out.println("On Select: " + newSelection.getFirstName() + " " + newSelection.getLastName() + " " + newSelection.getEmail());
});
完整代码:
导入javafx.application.application;
导入javafx.beans.property.SimpleStringProperty;
导入javafx.collections.FXCollections;
导入javafx.collections.ObservableList;
导入javafx.geometry.Insets;
导入javafx.scene.Group;
导入javafx.scene.scene;
导入javafx.scene.control.Label;
导入javafx.scene.control.TableColumn;
导入javafx.scene.control.TableView;
导入javafx.scene.control.cell.PropertyValueFactory;
导入javafx.scene.layout.VBox;
导入javafx.scene.text.Font;
导入javafx.stage.stage;
公共类TableViewSample扩展了应用程序
{
private final TableView table=new TableView();
私有最终可观测列表数据
=FXCollections.observableArrayList(
新人(“雅各布”、“史密斯”、“雅各布”。smith@example.com"),
新人(“伊莎贝拉”、“约翰逊”、“伊莎贝拉”。johnson@example.com"),
新人(“伊桑”、“威廉姆斯”、“伊桑”。williams@example.com"),
新人(“艾玛”、“琼斯”、“艾玛”。jones@example.com"),
新人(“迈克尔”、“布朗”、“迈克尔”。brown@example.com")
);
公共静态void main(字符串[]args)
{
发射(args);
}
@凌驾
公众假期开始(阶段)
{
场景=新场景(新组());
stage.setTitle(“表格视图示例”);
舞台布景宽度(450);
舞台设置高度(500);
最终标签=新标签(“地址簿”);
label.setFont(新字体(“Arial”,20));
table.setEditable(true);
TableColumn firstNameCol=新的TableColumn(“名字”);
firstNameCol.setMinWidth(100);
firstNameCol.setCellValueFactory(
新财产价值工厂(“名字”);
TableColumn lastNameCol=新的TableColumn(“姓氏”);
lastNameCol.setMinWidth(100);
lastNameCol.setCellValueFactory(
新财产价值工厂(“姓氏”);
TableColumn emailCol=新的TableColumn(“电子邮件”);
设置最小宽度(200);
emailCol.setCellValueFactory(
新物业价值工厂(“电子邮件”);
表2.设置项目(数据);
table.getColumns().addAll(firstNameCol、lastNameCol、emailCol);
最终VBox VBox=新的VBox();
vbox.setspace(5);
设置填充(新的插入(10,0,0,10));
vbox.getChildren().addAll(标签、表格);
((组)scene.getRoot()).getChildren().addAll(vbox);
舞台场景;
stage.show();
对于(int i=0;i{
System.out.println(“在选择时:”+newSelection.getFirstName()+“”+newSelection.getLastName()+“”+newSelection.getEmail());
});
}
公共静态类人员
{
私有最终SimpleStringProperty名字;
私有最终SimpleStringProperty姓氏;
私人最终SimpleStringProperty电子邮件;
私人(字符串fName、字符串lName、字符串电子邮件)
{
this.firstName=新的SimpleStringProperty(fName);
this.lastName=新的SimpleStringProperty(lName);
this.email=新的SimpleStringProperty(电子邮件);
}
公共字符串getFirstName()
{
返回firstName.get();
}
public void setFirstName(字符串fName)
{
firstName.set(fName);
}
公共字符串getLastName()
{
返回lastName.get();
}
public void setLastName(字符串fName)
{
lastName.set(fName);
}
公共字符串getEmail()
{
返回email.get();
}
public void setEmail(字符串fName)
{
email.set(fName);
}
}
}
我猜您可能没有选择任何内容,因此getSelectedItem()
返回null
。但是您的代码看起来有点奇怪-表应该绑定到您的模型,那么为什么您需要“扫描”表以了解它包含哪些数据呢?可能是.when tabel_otapproclInfo.getItems().size()时,它会获取所有数据并将其从表中删除。在我试图从表中获取这些数据后,出现了这个错误。我想从表中获取所有数据,但如何通过不发生空点异常来实现呢?感谢您的帮助,我不确定当您试图仅访问循环体中的选定元素时,为什么要检查循环中表的项列表的大小。注意:如果用户没有选择项目,则无论表中的项目数量如何,都会返回null
。
Person tempPerson = table.getItems().get(1);
System.out.println("Specifice index 1: " + tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());
table.getSelectionModel().selectedItemProperty().addListener((obs, oldSelection, newSelection) -> {
System.out.println("On Select: " + newSelection.getFirstName() + " " + newSelection.getLastName() + " " + newSelection.getEmail());
});
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
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")
);
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(500);
final Label label = new Label("Address Book");
label.setFont(new Font("Arial", 20));
table.setEditable(true);
TableColumn firstNameCol = new TableColumn("First Name");
firstNameCol.setMinWidth(100);
firstNameCol.setCellValueFactory(
new PropertyValueFactory<Person, String>("firstName"));
TableColumn lastNameCol = new TableColumn("Last Name");
lastNameCol.setMinWidth(100);
lastNameCol.setCellValueFactory(
new PropertyValueFactory<Person, String>("lastName"));
TableColumn emailCol = new TableColumn("Email");
emailCol.setMinWidth(200);
emailCol.setCellValueFactory(
new PropertyValueFactory<Person, String>("email"));
table.setItems(data);
table.getColumns().addAll(firstNameCol, lastNameCol, emailCol);
final VBox vbox = new VBox();
vbox.setSpacing(5);
vbox.setPadding(new Insets(10, 0, 0, 10));
vbox.getChildren().addAll(label, table);
((Group) scene.getRoot()).getChildren().addAll(vbox);
stage.setScene(scene);
stage.show();
for (int i = 0; i < table.getItems().size(); i++) {
Person tempPerson = table.getItems().get(i);
System.out.println(tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());
}
Person tempPerson = table.getItems().get(1);
System.out.println("Specifice index 1: " + tempPerson.getFirstName() + " " + tempPerson.getLastName() + " " + tempPerson.getEmail());
table.getSelectionModel().selectedItemProperty().addListener((obs, oldSelection, newSelection) -> {
System.out.println("On Select: " + newSelection.getFirstName() + " " + newSelection.getLastName() + " " + newSelection.getEmail());
});
}
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);
}
}
}