Java FX ComboBoxTableCell在每個單元格中顯示

Question

我有一個表格，它有一個組合單元格，您可以從每個行條目中選擇一個值。問題是，下拉列表僅顯示單元格正在編輯時的情況，我希望它始終顯示在每一行上。這是可能的，如果是這樣，如何？

TableColumn<Product, String> actionsCol = new TableColumn<Product, String>("Exception Reason"); 
    actionsCol.setCellValueFactory(new PropertyValueFactory("exceptionReason")); 
    actionsCol.setCellFactory(ComboBoxTableCell.forTableColumn(exceptionReasons)); 
    actionsCol.setOnEditCommit(
      new EventHandler<CellEditEvent<Product, String>>() { 
       @Override 
       public void handle(CellEditEvent<Product, String> t) { 
        ((Product) t.getTableView().getItems().get(t.getTablePosition().getRow())).setExceptionReason(t.getNewValue()); 
       }; 
    }); 
    actionsCol.setEditable(true); 

Answer 1

您可以通過實現自己的表格單元格（並設置單元格工廠進行實例化）做到這一點：

import java.util.Random; 

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.scene.Scene; 
import javafx.scene.control.ComboBox; 
import javafx.scene.control.TableCell; 
import javafx.scene.control.TableColumn; 
import javafx.scene.control.TableView; 
import javafx.stage.Stage; 

public class TableWithComboBoxExample extends Application { 

    @Override 
    public void start(Stage primaryStage) { 
     TableView<Item> table = new TableView<>(); 

     TableColumn<Item, String> itemCol = new TableColumn<>("Item"); 
     itemCol.setCellValueFactory(cellData -> cellData.getValue().nameProperty()); 

     TableColumn<Item, Reason> reasonCol = new TableColumn<>("Reason"); 
     reasonCol.setCellValueFactory(cellData -> cellData.getValue().importanceProperty()); 

     reasonCol.setCellFactory(tc -> { 
      ComboBox<Reason> combo = new ComboBox<>(); 
      combo.getItems().addAll(Reason.values()); 
      TableCell<Item, Reason> cell = new TableCell<Item, Reason>() { 
       @Override 
       protected void updateItem(Reason reason, boolean empty) { 
        super.updateItem(reason, empty); 
        if (empty) { 
         setGraphic(null); 
        } else { 
         combo.setValue(reason); 
         setGraphic(combo); 
        } 
       } 
      }; 
      combo.setOnAction(e -> 
       table.getItems().get(cell.getIndex()).setImportance(combo.getValue())); 
      return cell ; 
     }); 

     table.getColumns().add(itemCol); 
     table.getColumns().add(reasonCol); 

     Random rng = new Random(); 
     for (int i = 1 ; i <= 100 ; i++) { 
      table.getItems().add(new Item("Item "+i, Reason.values()[rng.nextInt(Reason.values().length)])); 
     } 

     primaryStage.setScene(new Scene(table)); 
     primaryStage.show(); 
    } 

    public enum Reason { DATA_NOT_OBTAINABLE, IM_JUST_PLAIN_LAZY, I_CANT_BE_BOTHERED } 

    public static class Item { 
     private final StringProperty name = new SimpleStringProperty(); 
     private final ObjectProperty<Reason> importance = new SimpleObjectProperty<>(); 

     public Item(String name, Reason importance) { 
      setName(name); 
      setImportance(importance); 
     } 

     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<Reason> importanceProperty() { 
      return this.importance; 
     } 


     public final Reason getImportance() { 
      return this.importanceProperty().get(); 
     } 


     public final void setImportance(final Reason importance) { 
      this.importanceProperty().set(importance); 
     } 



    } 

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