JavaFX组合框与复选框 [英] JavaFX ComboBox with CheckBoxes

问题描述

问题的描述

我尝试创建一个 JavaFX ComboBox 其在下拉菜单中包含复选框。
ComboBox 应该是可编辑的，并且可以通过一个简单的类来调用 > CheckItem 。
CheckItems 的列表应为可检查的，并且在选择后不会关闭下拉菜单。

最后， ComboBox 中的文本应该可用，并且选择（所有选中的项目）

我已经解决了

（1）a ComboBox 渲染 CheckItem as CheckedBox 正确选择

（2）从 ComboBox

出现的问题

下拉框关闭&

（2）据我所知，它一次只能选择一个 ？

这里是我测试这些东西的代码：

测试程序

public class ComboButtonSample extends应用程序{

@Override
public void start（Stage Stage）{
final ObservableList< ; CheckItem> items = fetchItems（）;
ComboBox< CheckItem> combo = createComboBox（items）;
combo.setPromptText（enter searchstring here）;
combo.setEditable（true）;


//垂直排列组件
VBox vBox = new VBox（）;
vBox.getChildren（）。add（combo）;

//用于写出组合框的文本和项目的按钮
Button btn = new Button（）;
btn.setText（combo text to console）;
btn.setOnAction（（event） - > {
System.out.println（Text is：+ combo.getEditor（）。getText（））;
System.out。 println（Content is：）;
for（Iterator< CheckItem> iterator = combo.getItems（）。iterator（）; iterator.hasNext（）;）{
CheckItem ci = .next（）;
System.out.println（String.format（[％s]％s - >％s，ci.selected？X：，ci.getDisplayName ci.getInternalName（）））;

}
}）;

vBox.getChildren（）。add（btn）;

//显示你不需要任何代码来改变框的选择。
CheckBox checkBox = new CheckBox（）;
checkBox.setText（test box）;
vBox.getChildren（）。add（checkBox）;

stage.setScene（new Scene（vBox））;
stage.show（）;
}

private ComboBox< CheckItem> createComboBox（ObservableList< CheckItem> data）{
ComboBox< CheckItem> combo = new ComboBox<>（）;
combo.getItems（）。addAll（data）;
combo.setCellFactory（listView - > new CheckItemListCell（））;
return combo;
}

class CheckItemListCell extends ListCell< CheckItem> {
private final CheckBox btn;

CheckItemListCell（）{
setContentDisplay（ContentDisplay.GRAPHIC_ONLY）;
btn = new CheckBox（）;
}

@Override
protected void updateItem（CheckItem item，boolean empty）{
super.updateItem（item，empty）;

if（item == null || empty）{
setGraphic（null）;
} else {
btn.setText（item.getDisplayName（））;
btn.selectedProperty（）。setValue（item.selected）;
setGraphic（btn）;
}
}
}

private ObservableList< CheckItem> fetchItems（）{
final ObservableList< CheckItem> data = FXCollections
.observableArrayList（）;
for（int i = 1; i <15; i ++）{
CheckItem chkItem = new CheckItem（）;
chkItem.selected = i％3 == 0;
chkItem.setDisplayName（DisplayName+ i）;
chkItem.setInternalName（InternalName+ i）;
data.add（chkItem）;
}
返回数据;
}

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


CheckItem

  public class CheckItem {
 boolean selected; 
 String displayName; 
 String internalName; 
 
 public boolean isChecked（）{
 return selected; 
} 
 
 public void setChecked（boolean checked）{
 this.selected = checked; 
} 
 
 public String getDisplayName（）{
 return displayName; 
} 
 
 public void setDisplayName（String displayName）{
 this.displayName = displayName; 
} 
 
 public String getInternalName（）{
 return internalName; 
} 
 
 public void setInternalName（String internalName）{
 this.internalName = internalName; 
} 
} 
  

解决方案

您在实施过程中遇到问题，您应该查看。

Description of the Question

I try to create a JavaFX ComboBox which holds CheckBoxes in the dropdown menu. The ComboBox shall be editable and gets fed by a simple Class lets call it CheckItem. the list of CheckItems shall be checkable - and shall not close the dropdown menu after a selection is made.

finally the Text in the ComboBox should be available and a Selection (all checked Items)

this is what i already worked out

(1) a ComboBox rendering the CheckItem as CheckedBox with correct selection

(2) gaining the Text from the ComboBox

problems coming up

(1) After clicking on one item the dropdown closes & selection state of the item does not change.

(2) As far as i noticed its only possible to have one item selected at a time?

here is my code for testing the stuff:

Test Program

public class ComboButtonSample extends Application {

    @Override
    public void start(Stage stage) {
            final ObservableList<CheckItem> items = fetchItems();
            ComboBox<CheckItem> combo = createComboBox(items);
            combo.setPromptText("enter searchstring here");
            combo.setEditable(true);


            // order the components vertically
            VBox vBox = new VBox();
            vBox.getChildren().add(combo);

            // Button to write out the text and the items of the combobox
            Button btn = new Button();
            btn.setText("combo text to console");
            btn.setOnAction((event) -> {
                    System.out.println("Text is: "+combo.getEditor().getText());
                    System.out.println("Content is: ");
                    for (Iterator<CheckItem> iterator = combo.getItems().iterator(); iterator.hasNext();) {
                            CheckItem ci = (CheckItem) iterator.next();
                            System.out.println(String.format("[%s] %s -> %s", ci.selected ? "X" : " ",ci.getDisplayName(), ci.getInternalName()));

                    }
            });

            vBox.getChildren().add(btn);

            // show you do not need any code to change the selection of the box.
            CheckBox checkBox = new CheckBox();
            checkBox.setText("test box");
            vBox.getChildren().add(checkBox);

            stage.setScene(new Scene(vBox));
            stage.show();
    }

    private ComboBox<CheckItem> createComboBox(ObservableList<CheckItem> data) {
            ComboBox<CheckItem> combo = new ComboBox<>();
            combo.getItems().addAll(data);
            combo.setCellFactory(listView -> new CheckItemListCell());
            return combo;
    }

    class CheckItemListCell extends ListCell<CheckItem> {
            private final CheckBox btn;

            CheckItemListCell() {
                    setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
                    btn = new CheckBox();
            }

            @Override
            protected void updateItem(CheckItem item, boolean empty) {
                    super.updateItem(item, empty);

                    if (item == null || empty) {
                            setGraphic(null);
                    } else {
                            btn.setText(item.getDisplayName());
                            btn.selectedProperty().setValue(item.selected);
                            setGraphic(btn);
                    }
            }
    }

    private ObservableList<CheckItem> fetchItems() {
            final ObservableList<CheckItem> data = FXCollections
                            .observableArrayList();
            for (int i = 1; i < 15; i++) {
                    CheckItem chkItem = new CheckItem();
                    chkItem.selected = i%3==0;
                    chkItem.setDisplayName("DisplayName" + i);
                    chkItem.setInternalName("InternalName" + i);
                    data.add(chkItem);
            }
            return data;
    }

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

CheckItem

public class CheckItem {
    boolean selected;
    String displayName;
    String internalName;    

    public boolean isChecked() {
        return selected;
    }

    public void setChecked(boolean checked) {
        this.selected = checked;
    }

    public String getDisplayName() {
        return displayName;
    }

    public void setDisplayName(String displayName) {
        this.displayName = displayName;
    }

    public String getInternalName() {
        return internalName;
    }

    public void setInternalName(String internalName) {
        this.internalName = internalName;
    }
}

解决方案

If you have problems in your implementation, you should have a look to the CheckComboBox control in the ControlsFX project.

Source code can be found here.

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