我有一个TableView和Data类，其中包含列的整数属性。但是我希望列首先显示空单元格，以便用户可以放置他想要的值。
现在它是不可能的，因为在创建Data对象时，必须使用初始值创建整数值，因此表格显示已填充数字。
private ObservableList<MyData> dataList = FXCollections.observableArrayList();
.....编辑...
private void buttAddColumnAction(ActionEvent event){
int i = numberOfColumns;// thats the key for lambda expression. Unicate number for column to access its variable;
if(dataList.size() > 0)//resizing each data object with new variable
for(MyData x: dataList)
x.addNew();
TableColumn<MyData, Integer> newColumn = new TableColumn<>("#" + String.valueOf(++numberOfColumns));
newColumn.setCellValueFactory(cellData -> cellData.getValue().getCellValue(i));
// newColumn.setCellFactory(TextFieldTableCell.<MyData, Integer>forTableColumn(new IntegerStringConverter()));
Callback<TableColumn<MyData, Integer>, TableCell<MyData, Integer>> cellFactoryInt = (TableColumn<MyData, Integer> p) -> new EditingCellNumbers(tableView);
newColumn.setCellFactory(cellFactoryInt);
tableView.getColumns().add(newColumn);
}
public class MyData{ //dont forget about public because you wont get acces to properties
private ObservableList<ObjectProperty<Integer>> cellValue = FXCollections.observableArrayList();
public MyData(int howManyColumns) {
for(int i=0; i<howManyColumns; ++i)
this.cellValue.add(new SimpleObjectProperty<Integer>(null));
}
public ObjectProperty<Integer> getCellValue(int whichOne) {
return cellValue.get(whichOne);
}
public void setCellValue(int cellValue, int whichOne) {
this.cellValue.set(whichOne, new SimpleObjectProperty<Integer>(cellValue));
}
public void addNew(){ //ads another variable for another column
cellValue.add(new SimpleObjectProperty<Integer>(null));
}
public void deleteLast(){ //deletes last variable when column is deleted
cellValue.remove(cellValue.size()-1);
}
}
CellFactory
//Klasa ta pozwala na definiowania zachowania komórek, które edytuje użytkownik
public class EditingCellNumbers extends TableCell<MyData, Integer>{
private TextField textField;
private TableView<MyData> parentTableView;
public static int numberOfColumns;
public EditingCellNumbers(TableView<MyData> parent) {
this.parentTableView = parent;
numberOfColumns = parent.getColumns().size();
}
@Override
public void startEdit(){
if (!isEmpty()) {
super.startEdit();
createTextField();
setText(null);
setGraphic(textField);
textField.selectAll();
textField.requestFocus();
}
}
@Override
public void cancelEdit() {
super.cancelEdit();
setText(String.valueOf(getItem()));
setGraphic(null);
}
@Override
public void updateItem(Integer item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
if (isEditing()) {
if (textField != null) {
textField.setText(getString());
}
setText(null);
setGraphic(textField);
} else {
setText(getString());
setGraphic(null);
}
}
}
private void createTextField() {
textField = new TextField(getString());
textField.setMinWidth(this.getWidth() - this.getGraphicTextGap()* 2);
textField.focusedProperty().addListener(
(ObservableValue<? extends Boolean> arg0,
Boolean arg1, Boolean arg2) -> {
if (!arg2) {
XXX commitEdit(Integer.valueOf(textField.getText()));
}
});
textField.setOnKeyReleased(new EventHandler<Event>() {
@Override
public void handle(Event event) {
try{
int i = Integer.valueOf(textField.getText());
//digit given...
if( (i>=0) && (i<10) ){//making sure cell is filled with just one digit
commitEdit(Integer.valueOf(textField.getText()));
int selectedColumn = parentTableView.getSelectionModel().getSelectedCells().get(0).getColumn(); // gets the number of selected column
int selectedRow = parentTableView.getSelectionModel().getSelectedCells().get(0).getRow();
if(selectedColumn < numberOfColumns-1){
parentTableView.getSelectionModel().selectNext();
parentTableView.edit(selectedRow, parentTableView.getColumns().get(selectedColumn+1));
}else{
parentTableView.getSelectionModel().select(selectedRow+1, parentTableView.getColumns().get(0));
parentTableView.edit(selectedRow+1, parentTableView.getColumns().get(0));
}
}else
textField.clear();
}catch(NumberFormatException e){
textField.clear();
}
}
});
}
private String getString() {
return getItem() == null ? "" : getItem().toString();
}
}
答案 0 :(得分：2)
使用null代替ObjectProperty<Integer>，在列中添加IntegerProperty个值。这提供了一种更自然的方式来定义＆＃34;未初始化＆＃34;而不是用0（或其他代理值）表示它。
然后您可以使用TextFieldTableCell，但只提供自定义StringConverter<Integer>：
public class MyData{ //dont forget about public because you wont get acces to properties
private ObservableList<ObjectProperty<Integer>> cellValue = FXCollections.observableArrayList();
public MyData(int howManyColumns) {
for(int i=0; i<howManyColumns; ++i)
this.cellValue.add(new SimpleObjectProperty<>(new Random().nextInt(10)));
}
// ...
}
和
newColumn.setCellValueFactory(cellData -> cellData.getValue().getCellValue(i));
newColumn.setCellFactory(TextFieldTableCell.<MyData, Integer>forTableColumn(new StringConverter<Integer>() {
@Override
public String toString(Integer i) {
if (i == null) {
return "" ;
} else {
return i.toString();
}
}
@Override
public Integer fromString(String string) {
if (string.trim().length() == 0) {
return null ;
} else {
try {
return Integer.valueOf(string);
} catch (NumberFormatException nfe) {
return null ;
}
}
}
}));
完整示例：
import java.util.Random;
import java.util.function.Function;
import javafx.application.Application;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import javafx.util.StringConverter;
public class TableViewWithEmptyIntegerColumn extends Application {
@Override
public void start(Stage primaryStage) {
TableView<Item> table = new TableView<>();
table.setEditable(true);
TableColumn<Item, String> nameCol = createCol("Name", Item::nameProperty);
TableColumn<Item, Integer> valueCol = createCol("Value", Item::valueProperty);
valueCol.setEditable(true);
valueCol.setCellFactory(TextFieldTableCell.forTableColumn(new StringConverter<Integer>() {
@Override
public String toString(Integer i) {
if (i == null) {
return "" ;
} else {
return i.toString() ;
}
}
@Override
public Integer fromString(String string) {
if (string.trim().length() == 0) {
return null ;
} else {
// better to check for a valid int format instead of using try-catch...
try {
return Integer.valueOf(string);
} catch (NumberFormatException nfe) {
return null ;
}
}
}
}));
Random rng = new Random();
for (int i=1; i<=20; i++) {
if (rng.nextDouble() < 0.5) {
table.getItems().add(new Item("Item "+i));
} else {
table.getItems().add(new Item("Item "+i, rng.nextInt(10)+1));
}
}
table.getColumns().addAll(nameCol, valueCol);
primaryStage.setScene(new Scene(new BorderPane(table), 400, 600));
primaryStage.show();
}
private <S,T> TableColumn<S,T> createCol(String title, Function<S, ObservableValue<T>> property) {
TableColumn<S,T> col = new TableColumn<>(title);
col.setCellValueFactory(cellData -> property.apply(cellData.getValue()));
return col ;
}
public static class Item {
private final StringProperty name = new SimpleStringProperty();
private final ObjectProperty<Integer> value = new SimpleObjectProperty<>();
public Item(String name, Integer value) {
setName(name);
setValue(value);
}
public Item(String name) {
this(name, null);
}
public final StringProperty nameProperty() {
return this.name;
}
public final String getName() {
return this.nameProperty().get();
}
public final void setName(final String name) {
this.nameProperty().set(name);
}
public final ObjectProperty<Integer> valueProperty() {
return this.value;
}
public final Integer getValue() {
return this.valueProperty().get();
}
public final void setValue(final Integer value) {
this.valueProperty().set(value);
}
}
public static void main(String[] args) {
launch(args);
}
}