我使用的javafx表视图具有主动排序功能,并且每毫秒插入一个新行。。。
我想要这个功能:
如果我选择了一行,那么当插入新行时,它应该保持可见(也就是说,不应该从表的当前可见部分向上或向下)。
这可能还有很长的路要走,而且有点过时,但当我需要做类似的事情时,它对我很有效。
答案的要点是,您需要访问TableViewSkin
的VirtualFlow
成员。这并不像听起来那么简单,因为在解析CSS之前不会加载皮肤。我在TableView
的skinProperty
上添加了一个Listener
,并能够以这种方式获得VirtualFlow
。
tableView.skinProperty().addListener(new ChangeListener<Skin>()
{
@Override
public void changed(ObservableValue<? extends Skin> ov, Skin t, Skin t1)
{
if (t1 == null) { return; }
TableViewSkin tvs = (TableViewSkin)t1;
ObservableList<Node> kids = tvs.getChildrenUnmodifiable();
if (kids == null || kids.isEmpty()) { return; }
flow = (VirtualFlow)kids.get(1);
}
});
有了VirtualFlow
之后,可以侦听表的ObservableList
以了解更改,并进行检查以确保选定项目仍在视口中。
countries.addListener(new ListChangeListener<Country>()
{
@Override
public void onChanged(ListChangeListener.Change<? extends Country> change)
{
while (change.next())
{
if (change.wasAdded())
{
if (flow == null) { return; }
int first = flow.getFirstVisibleCell().getIndex();
int last = flow.getLastVisibleCell().getIndex();
int selected = tableView.getSelectionModel().getSelectedIndex();
if (selected < first || selected > last)
{
flow.show(selected);
}
}
}
}
});
仍将有一些记账工作需要管理。例如,如果你想把焦点放回桌子上。此外,值得注意的是,VirtualFlow
不受表的可见矩形的严格约束,因此即使项目位于视口之外,也可能被视为可见。您可以研究VirtualFlow以了解更多详细信息。
这是SSCCE。
JavaFXApplication21.java:
package javafxapplication21;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class JavaFXApplication21 extends Application
{
@Override
public void start(Stage stage) throws Exception
{
Parent root = FXMLLoader.load(getClass().getResource("Sample.fxml"));
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args)
{
launch(args);
}
}
Sample.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<AnchorPane id="AnchorPane" prefHeight="200.0" prefWidth="200.0" xmlns:fx="http://javafx.com/fxml" fx:controller="javafxapplication21.SampleController">
<children>
<ToolBar AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<items>
<Button fx:id="insertBtn" mnemonicParsing="false" text="Insert" />
</items>
</ToolBar>
<TableView fx:id="tableView" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="31.0">
<columns>
<TableColumn prefWidth="100.0" text="Country" fx:id="countryColumn" />
<TableColumn prefWidth="100.0" text="Capital" fx:id="capitalColumn" />
</columns>
</TableView>
</children>
</AnchorPane>
SampleController.java:
package javafxapplication21;
import com.sun.javafx.scene.control.skin.TableViewSkin;
import com.sun.javafx.scene.control.skin.VirtualFlow;
import java.net.URL;
import java.util.*;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.*;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.control.*;
import javafx.scene.control.cell.PropertyValueFactory;
public class SampleController implements Initializable
{
@FXML private Button insertBtn;
@FXML private TableView<Country> tableView;
@FXML private TableColumn<Country, String> countryColumn;
@FXML private TableColumn<Country, String> capitalColumn;
private VirtualFlow flow;
private ObservableList<Country> countries =
FXCollections.observableArrayList();
private List<Country> insertList = new ArrayList<>();
public SampleController()
{
countries.addAll(new Country("AG", "Buenos Aires"),
new Country("AU", "Vienna"),
new Country("BY", "Minsk"),
new Country("CO", "Bogota"),
new Country("EG", "Cairo"));
insertList.add(new Country("ZI", "Harare"));
insertList.add(new Country("UK", "London"));
insertList.add(new Country("TW", "Taipei"));
}
@Override
public void initialize(URL url, ResourceBundle rb)
{
countryColumn.setCellValueFactory(
new PropertyValueFactory<Country, String>("name"));
capitalColumn.setCellValueFactory(
new PropertyValueFactory<Country, String>("capital"));
tableView.setItems(countries);
tableView.skinProperty().addListener(new ChangeListener<Skin>()
{
@Override
public void changed(ObservableValue<? extends Skin> ov,
Skin t, Skin t1)
{
if (t1 == null) { return; }
TableViewSkin tvs = (TableViewSkin)t1;
ObservableList<Node> kids = tvs.getChildrenUnmodifiable();
if (kids == null || kids.isEmpty()) { return; }
flow = (VirtualFlow)kids.get(1);
}
});
insertBtn.setOnAction(new EventHandler<ActionEvent>()
{
@Override
public void handle(ActionEvent t)
{
if (!insertList.isEmpty())
{
countries.add(2, insertList.get(0));
insertList.remove(0);
}
}
});
countries.addListener(new ListChangeListener<Country>()
{
@Override
public void onChanged(ListChangeListener.Change<? extends Country> change)
{
while (change.next())
{
if (change.wasAdded())
{
if (flow == null) { return; }
int first = flow.getFirstVisibleCell().getIndex();
int last = flow.getLastVisibleCell().getIndex();
int selected = tableView.getSelectionModel().getSelectedIndex();
if (selected < first || selected > last)
{
flow.show(selected);
}
}
}
}
});
}
public class Country
{
private SimpleStringProperty name;
private SimpleStringProperty capital;
public Country(String name, String capital)
{
this.name = new SimpleStringProperty(name);
this.capital = new SimpleStringProperty(capital);
}
public SimpleStringProperty nameProperty() { return name; }
public SimpleStringProperty capitalProperty() { return capital; }
}
}
我也遇到了同样的问题。您可以使用cellEventHandler类,当在表中选择单元格并将最后选择的行索引设置为变量时,该类将触发EventHandler接口。课程如下。
public class CellEventHandler implements EventHandler<MouseEvent>
{
CellEventHandler()
{
}
@Override
public void handle(MouseEvent t)
{
TableCell c;
c = (TableCell) t.getSource();
c.getIndex();
PanelController.selectedItem = c.getIndex();
}
}`
然后,PanelController类中表的表类呈现应该如下所示。
typeCol.setCellFactory(new Callback<TableColumn<tableModel, String>, TableCell<tableModel, String>>()
{
@Override
public TableCell<tableModel, String> call(TableColumn<tableModel, String> tableColumn)
{
LableCell lableCell = new LableCell(Pos.CENTER, true);
lableCell.addEventFilter(MouseEvent.MOUSE_CLICKED, new CellEventHandler());
return lableCell;
}
});
"selectedItem"字段应在panelController类中声明为静态字段,然后在刷新表行数据时,"selectedItem"应在表中设置为selected。
myTable.getSelectionModel().select(selectedItem);
这适用于我:
tableView.getSelectionModel().selectedIndexProperty().addListener((observable,oldValue,t1)->{
TableViewSkin tvs = (TableViewSkin)tableView.getSkin();
ObservableList<Node> kids = tvs.getChildren();
if (kids == null || kids.isEmpty()) { return; }
VirtualFlow flow = (VirtualFlow)kids.get(1);
int first =-1;
if (flow.getFirstVisibleCell() != null) first = flow.getFirstVisibleCell().getIndex();
int last = -1;
if (flow.getFirstVisibleCell() != null) last = flow.getLastVisibleCell().getIndex();
if(first !=-1 && t1.intValue()<first)
flow.scrollTo(t1.intValue());
if(last != -1 && t1.intValue()>last)
flow.scrollTo(t1.intValue()+1);
});