列表视图单元格加载空白而不是自定义单元格
我尝试使用调试工具重建fxml文件，但这些方法都无济于事。我在网上进行了广泛研究，但只能找到有关Javafx listview较旧版本的指南。
在有人告诉我updateItem代码是错误的之前，请先帮助我使其工作，然后至少可以从某个地方开始对其进行优化
package Test;
import java.io.IOException;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.Label;
import javafx.scene.control.ListCell;
import javafx.scene.layout.Pane;
import org.controlsfx.glyphfont.Glyph;
/**
* FXML Controller class
*
* @author james
*/
public class ListCellController2 extends ListCell<Student>
{
FXMLLoader loader;
@FXML
private Glyph attendenceSymbolGlyph;
@FXML
private Label studentDetailsLabel;
@FXML
private Pane entryPane;
@Override
protected void updateItem(Student student, boolean empty)
{
super.updateItem(student, empty);
if (empty || student == null)
{
setText(null);
setGraphic(null);
}
else
{
loader = new FXMLLoader(getClass().getResource("ListCell2.fxml"));
try
{
loader.load();
studentDetailsLabel.setText(student.toString());
setGraphic(entryPane);
}
catch (IOException ex)
{
ex.printStackTrace();
}
}
}
}
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.Pane?>
<?import org.controlsfx.glyphfont.Glyph?>
<Pane fx:id="entryPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="95.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Test.ListCellController2">
<children>
<Glyph id="attendenceSymbolGlyph" fx:id="attendenceSymbolGlyph" layoutX="5.0" layoutY="8.0" prefHeight="80.0" prefWidth="87.0" />
<Label id="studentDetailsLabel" fx:id="studentDetailsLabel" layoutX="113.0" layoutY="5.0" prefHeight="88.0" prefWidth="482.0" text="Label" />
</children>
</Pane>
package Test;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.util.Callback;
/**
* FXML Controller class
*
* @author james
*/
public class MainController implements Initializable {
@FXML
public ListView<Student> myListView;
public ObservableList<Student> studentList;
public MainController()
{
studentList = FXCollections.observableArrayList();
studentList.add(new Student("Jimmy", "u0764987", "ef937b3"));
studentList.add(new Student("John", "u0762809", "543jh32"));
}
public void setupListView()
{
try
{
myListView.setItems((ObservableList)studentList);
myListView.setCellFactory(new Callback<ListView<Student>, ListCell<Student>>()
{
@Override
public ListCell<Student> call(ListView<Student> p)
{
return new ListCellController();
}
});
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
/**
* Initializes the controller class.
*/
@Override
public void initialize(URL location, ResourceBundle resources)
{
if (!studentList.isEmpty())
{
setupListView();
}
else
{
System.out.println("student list is empty");
}
}
}
我的预期结果是将数据加载到自定义单元格中然后显示它，它的实际作用是给我一个空白单元格
答案 0 :(得分：0)
似乎您创建了ListCellController2类的两个实例。
我还建议您在创建单元格时只加载一次列表单元组件，而不是每次显示新值时都加载。
控制器由单元工厂创建，实例由FXML-loader使用。这样，用@FXML注释的字段将被正确初始化。
这是我的代码：
import java.net.URL;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ListView;
public class MainController implements Initializable {
@FXML
public ListView<Student> myListView;
public ObservableList<Student> studentList;
public MainController() {
studentList = FXCollections.observableArrayList();
studentList.add(new Student("Jimmy", "u0764987", "ef937b3"));
studentList.add(new Student("John", "u0762809", "543jh32"));
}
@Override
public void initialize(URL location, ResourceBundle resources) {
if (!studentList.isEmpty()) {
setupListView();
} else {
System.out.println("student list is empty");
}
}
private void setupListView() {
myListView.setItems(studentList);
myListView.setCellFactory((listView) -> new ListCellController2());
}
}
import java.io.IOException;
import org.controlsfx.glyphfont.Glyph;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.Label;
import javafx.scene.control.ListCell;
import javafx.scene.layout.Pane;
public class ListCellController2 extends ListCell<Student> {
@FXML
private Glyph attendenceSymbolGlyph;
@FXML
private Label studentDetailsLabel;
@FXML
private Pane entryPane;
public ListCellController2() {
try {
FXMLLoader loader = new FXMLLoader();
loader.setController(this);
loader.setLocation(getClass().getResource("ListCell2.fxml"));
loader.load();
} catch (IOException e) {
throw new RuntimeException("Creating UI component failed", e);
}
}
@Override
protected void updateItem(Student student, boolean empty) {
super.updateItem(student, empty);
if (empty || student == null) {
setText(null);
setGraphic(null);
} else {
studentDetailsLabel.setText(student.toString());
setGraphic(entryPane);
}
}
}
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.Pane?>
<?import org.controlsfx.glyphfont.Glyph?>
<Pane fx:id="entryPane" prefHeight="95.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1">
<children>
<Glyph id="attendenceSymbolGlyph" fx:id="attendenceSymbolGlyph" layoutX="5.0" layoutY="8.0" prefHeight="80.0" prefWidth="87.0" />
<Label id="studentDetailsLabel" fx:id="studentDetailsLabel" layoutX="113.0" layoutY="5.0" prefHeight="88.0" prefWidth="482.0" text="Label" />
</children>
</Pane>