我想要一个ComboBox,它按照用户类型过滤列表项。它应该如下工作:
有没有可用的东西?
答案 0 :(得分:10)
就下拉的过滤而言。是不是将FilteredList
中的可能选项列表包装成最佳解决方案?
MCVE:
import javafx.application.Application;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.collections.transformation.FilteredList;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.TextField;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
public class MCVE extends Application {
public void start(Stage stage) {
HBox root = new HBox();
ComboBox<String> cb = new ComboBox<String>();
cb.setEditable(true);
// Create a list with some dummy values.
ObservableList<String> items = FXCollections.observableArrayList("One", "Two", "Three", "Four", "Five", "Six",
"Seven", "Eight", "Nine", "Ten");
// Create a FilteredList wrapping the ObservableList.
FilteredList<String> filteredItems = new FilteredList<String>(items, p -> true);
// Add a listener to the textProperty of the combobox editor. The
// listener will simply filter the list every time the input is changed
// as long as the user hasn't selected an item in the list.
cb.getEditor().textProperty().addListener((obs, oldValue, newValue) -> {
final TextField editor = cb.getEditor();
final String selected = cb.getSelectionModel().getSelectedItem();
// This needs run on the GUI thread to avoid the error described
// here: https://bugs.openjdk.java.net/browse/JDK-8081700.
Platform.runLater(() -> {
// If the no item in the list is selected or the selected item
// isn't equal to the current input, we refilter the list.
if (selected == null || !selected.equals(editor.getText())) {
filteredItems.setPredicate(item -> {
// We return true for any items that starts with the
// same letters as the input. We use toUpperCase to
// avoid case sensitivity.
if (item.toUpperCase().startsWith(newValue.toUpperCase())) {
return true;
} else {
return false;
}
});
}
});
});
cb.setItems(filteredItems);
root.getChildren().add(cb);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch();
}
}
答案 1 :(得分:2)
看看:
import javafx.application.Platform;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.control.ComboBox;
import javafx.scene.control.TextField;
public class FilterComboBox extends ComboBox<String> {
private ObservableList<String> initialList;
private ObservableList<String> bufferList = FXCollections.observableArrayList();
private String previousValue = "";
public FilterComboBox(ObservableList<String> items) {
super(items);
super.setEditable(true);
this.initialList = items;
this.configAutoFilterListener();
}
private void configAutoFilterListener() {
final FilterComboBox currentInstance = this;
this.getEditor().textProperty().addListener(new ChangeListener<String>() {
@Override
public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
previousValue = oldValue;
final TextField editor = currentInstance.getEditor();
final String selected = currentInstance.getSelectionModel().getSelectedItem();
if (selected == null || !selected.equals(editor.getText())) {
filterItems(newValue, currentInstance);
currentInstance.show();
if (currentInstance.getItems().size() == 1) {
setUserInputToOnlyOption(currentInstance, editor);
}
}
}
});
}
private void filterItems(String filter, ComboBox<String> comboBox) {
if (filter.startsWith(previousValue) && !previousValue.isEmpty()) {
ObservableList<String> filteredList = this.readFromList(filter, bufferList);
bufferList.clear();
bufferList = filteredList;
} else {
bufferList = this.readFromList(filter, initialList);
}
comboBox.setItems(bufferList);
}
private ObservableList<String> readFromList(String filter, ObservableList<String> originalList) {
ObservableList<String> filteredList = FXCollections.observableArrayList();
for (String item : originalList) {
if (item.toLowerCase().startsWith(filter.toLowerCase())) {
filteredList.add(item);
}
}
return filteredList;
}
private void setUserInputToOnlyOption(ComboBox<String> currentInstance, final TextField editor) {
final String onlyOption = currentInstance.getItems().get(0);
final String currentText = editor.getText();
if (onlyOption.length() > currentText.length()) {
editor.setText(onlyOption);
Platform.runLater(new Runnable() {
@Override
public void run() {
editor.selectRange(currentText.length(), onlyOption.length());
}
});
}
}
}
它基于此forum中的答案。希望这会有所帮助。
答案 2 :(得分:1)
我搜索了一段时间并找到了这个。 看看:
public class AutoCompleteComboBoxListener<T> implements EventHandler<KeyEvent> {
private ComboBox comboBox;
private StringBuilder sb;
private ObservableList<T> data;
private boolean moveCaretToPos = false;
private int caretPos;
public AutoCompleteComboBoxListener(final ComboBox comboBox) {
this.comboBox = comboBox;
sb = new StringBuilder();
data = comboBox.getItems();
this.comboBox.setEditable(true);
this.comboBox.setOnKeyPressed(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent t) {
comboBox.hide();
}
});
this.comboBox.setOnKeyReleased(AutoCompleteComboBoxListener.this);
}
@Override
public void handle(KeyEvent event) {
ListView lv = ((ComboBoxListViewSkin) comboBox.getSkin()).getListView();
if(event.getCode() == KeyCode.UP) {
caretPos = -1;
moveCaret(comboBox.getEditor().getText().length());
return;
} else if(event.getCode() == KeyCode.DOWN) {
if(!comboBox.isShowing()) {
comboBox.show();
}
caretPos = -1;
moveCaret(comboBox.getEditor().getText().length());
return;
} else if(event.getCode() == KeyCode.BACK_SPACE) {
moveCaretToPos = true;
caretPos = comboBox.getEditor().getCaretPosition();
} else if(event.getCode() == KeyCode.DELETE) {
moveCaretToPos = true;
caretPos = comboBox.getEditor().getCaretPosition();
}
if (event.getCode() == KeyCode.RIGHT || event.getCode() == KeyCode.LEFT
|| event.isControlDown() || event.getCode() == KeyCode.HOME
|| event.getCode() == KeyCode.END || event.getCode() == KeyCode.TAB) {
return;
}
ObservableList list = FXCollections.observableArrayList();
for (int i=0; i<data.size(); i++) {
if(data.get(i).toString().toLowerCase().startsWith(
AutoCompleteComboBoxListener.this.comboBox
.getEditor().getText().toLowerCase())) {
list.add(data.get(i));
}
}
String t = comboBox.getEditor().getText();
comboBox.setItems(list);
comboBox.getEditor().setText(t);
if(!moveCaretToPos) {
caretPos = -1;
}
moveCaret(t.length());
if(!list.isEmpty()) {
comboBox.show();
}
}
private void moveCaret(int textLength) {
if(caretPos == -1) {
comboBox.getEditor().positionCaret(textLength);
} else {
comboBox.getEditor().positionCaret(caretPos);
}
moveCaretToPos = false;
}
}
您可以使用
进行调用new AutoCompleteComboBoxListener<>(comboBox);
它基于this,我根据自己的需要对其进行了定制。
随意使用它,如果有人可以改进它,请告诉我。