Java没有为addListener找到合适的方法

Question

I've tried to generate a listener for a list view which gets the string stored in the item selected, gets an integer for it and then calls a method. However I keep getting a

Error:(37, 67) java: no suitable method found for addListener(<anonymous javafx.beans.value.ChangeListener<java.lang.String>>)
    method javafx.beans.Observable.addListener(javafx.beans.InvalidationListener) is not applicable
      (argument mismatch; <anonymous javafx.beans.value.ChangeListener<java.lang.String>> cannot be converted to javafx.beans.InvalidationListener)
    method javafx.collections.ObservableList.addListener(javafx.collections.ListChangeListener<? super java.lang.String>) is not applicable
      (argument mismatch; <anonymous javafx.beans.value.ChangeListener<java.lang.String>> cannot be converted to javafx.collections.ListChangeListener<? super java.lang.String>)

error. I have a similar listener but it only reads an object from the list not the text.

My listener is as follows:

lstRequests.getSelectionModel().getSelectedItems().addListener(new ChangeListener<String>(){
                        @Override
                        public void changed(ObservableValue<? extends String> observable,
                                            String oldValue, String newValue) {
                                int requestID;
                                int endIndex = 5;
                                String requestIDSubString =
                                        newValue.substring(5,endIndex);
                                boolean isADigit;
                                do{
                                        isADigit =
                                                isDigit(requestIDSubString.charAt(endIndex));
                                        endIndex++;
                                        requestIDSubString =
                                                newValue.substring(5,endIndex);
                                } while (isADigit);
                                endIndex--;
                                requestID =
                                        Integer.parseInt(newValue.substring(5
                                                ,endIndex));
                                Request selectedRequest = null;
                                Boolean requestFound = false;
                                int checkIndex = 0;
                                do {
                                        Request checkRequest =
                                                requests.get(checkIndex);
                                        if (checkRequest.getRequestID() == requestID){
                                                selectedRequest = checkRequest;
                                                requestFound = true;
                                        }
                                } while (!requestFound);

                                populateItems(selectedRequest); //Calls the populate
                                // items method.
                        }
                });

And my imports are:

import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.fxml.FXML;
import javafx.scene.control.ListView;
import java.util.ArrayList;
import static java.lang.Character.isDigit;

Any ideas how to fix this?

Answer 1

Currently you're trying to add a ChangeListener to a ObservableList . getSelectedItems() returns an ObservableList containing all the selected items. ObservableList s don't allow you to add a ChangeListener .

If you want to use a listener for a single selection, you should add the listener to the selectedItem property:

lstRequests.getSelectionModel().selectedItemProperty().addListener(...);