Question

现在我已经使用JavaFx完成了一个简单的Web浏览器。我设法做了一个backButton ....但是一个forwardButton我没有成功。此外，我想到了一个按钮，它将打开一个列表，其中包含在JavaFx浏览器中访问过的所有超链接（或链接）。如何让后退按钮工作？如何用一个按钮打开一个带有最后访问页面的hiperlinks（或链接）的窗口？（我想到了一个DefaultListModel和一个ArrayList，但我对你的意见不满意）。提前致谢！ :)

这是我的代码：

    backButton.setOnAction(new EventHandler<javafx.event.ActionEvent>() {
        public void handle(javafx.event.ActionEvent event) {

            int sizeHistory = webEngine.getHistory().getEntries().size();
      if(sizeHistory>1)       {


          Entry entry = webEngine.getHistory().getEntries().get(sizeHistory-2); 

         webEngine.load(entry.getUrl());
        }
        }
    });

     forwardButton.setOnAction(new EventHandler<javafx.event.ActionEvent>() {
        public void handle(javafx.event.ActionEvent event) {

            int sizeHistory = webEngine.getHistory().getEntries().size();
      if(sizeHistory>1)       {


          Entry entry = webEngine.getHistory().getEntries().get(sizeHistory);
          System.out.println("URL hist.: " + entry.getUrl());
         webEngine.load(entry.getUrl());
        }
        }
    });
             }

Answer 1

我真的不明白你的后退和前进按钮。您计算为sizeHistory的值只是访问过的页面总数（并存储在历史记录中）。当然，处理程序应该只是

backButton.setOnAction(e -> webEngine.getHistory().go(-1));
forwardButton.setOnAction(e -> webEngine.getHistory().go(1));

对于问题的其他部分，您可以创建一个ListView来显示历史记录中的条目：

ListView<WebHistory.Entry> historyView = new ListView<>();
historyView.setItems(history.getEntries());

只需做一点工作，您就可以让列表中的单元格显示相应页面的标题：

historyView.setCellFactory(lv -> new ListCell<WebHistory.Entry>() {
    @Override
    public void updateItem(WebHistory.Entry entry, boolean empty) {
        super.updateItem(entry, empty);
        textProperty().unbind();
        if (empty) {
            setText(null);
        } else {
            textProperty().bind(entry.titleProperty());
        }
    }
});

并且您可以使用几个侦听器将选择绑定到历史记录的当前索引：

history.currentIndexProperty().addListener((obs, oldIndex, newIndex) -> {
    if (newIndex.intValue() != historyView.getSelectionModel().getSelectedIndex()) {
        historyView.getSelectionModel().clearAndSelect(newIndex.intValue());
    }
});

historyView.getSelectionModel().selectedIndexProperty().addListener((obs, oldValue, newValue) -> {
    if (newValue.intValue() != history.getCurrentIndex()) {
        history.go(newValue.intValue() - history.getCurrentIndex());
    }
});

SSCCE：

import java.util.regex.Pattern;

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.concurrent.Worker.State;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;
import javafx.scene.web.WebHistory;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class WebBrowser extends Application {

    private TextField textField ;
    private WebView webView ;

    @Override
    public void start(Stage primaryStage) {
        webView = new WebView();

        webView.getEngine().getLoadWorker().stateProperty().addListener((obs, oldState, newState) -> {
            if (newState == State.SUCCEEDED) {
                primaryStage.setTitle(webView.getEngine().getTitle());
                textField.setText(webView.getEngine().getLocation());
            }
        });

        textField = new TextField("http://stackoverflow.com/questions/32802248/");
        textField.setOnAction(e -> load());

        load();

        Button clearButton = new Button("Clear");
        clearButton.setOnAction(e -> webView.getEngine().loadContent(""));

        WebHistory history = webView.getEngine().getHistory() ;

        Button backButton =  new Button("Back");
        backButton.disableProperty().bind(history.currentIndexProperty().lessThanOrEqualTo(0));
        backButton.setOnAction(e -> 
                history.go(-1));

        Button forwardButton = new Button("Forward");
        forwardButton.disableProperty().bind(
                history.currentIndexProperty().greaterThanOrEqualTo(Bindings.size(history.getEntries()).subtract(1)));
        forwardButton.setOnAction(e -> 
                history.go(1));

        HBox controls = new HBox(10, textField, backButton, clearButton, forwardButton);
        HBox.setHgrow(textField, Priority.ALWAYS);
        controls.setPadding(new Insets(10));

        ListView<WebHistory.Entry> historyView = new ListView<>();
        historyView.setItems(history.getEntries());
        historyView.setCellFactory(lv -> new ListCell<WebHistory.Entry>() {
            @Override
            public void updateItem(WebHistory.Entry entry, boolean empty) {
                super.updateItem(entry, empty);
                textProperty().unbind();
                if (empty) {
                    setText(null);
                } else {
                    textProperty().bind(entry.titleProperty());
                }
            }
        });

        history.currentIndexProperty().addListener((obs, oldIndex, newIndex) -> {
            if (newIndex.intValue() != historyView.getSelectionModel().getSelectedIndex()) {
                historyView.getSelectionModel().clearAndSelect(newIndex.intValue());
            }
        });

        historyView.getSelectionModel().selectedIndexProperty().addListener((obs, oldValue, newValue) -> {
            if (newValue.intValue() != history.getCurrentIndex()) {
                history.go(newValue.intValue() - history.getCurrentIndex());
            }
        });

        BorderPane root = new BorderPane(webView, controls, historyView, null, null);

        textField.setPadding(new Insets(5));
        root.setPadding(new Insets(5));
        Scene scene = new Scene(root, 800, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }


    private void load() {
        String url = makeUrl(textField.getText()) ;
        webView.getEngine().load(url);
        textField.setText(url);
    }


    private String makeUrl(String text) {
        if (Pattern.matches("[a-zA-Z]+:.+", text)) {
            return text ;
        } else return "http://"+text ;
    }

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

如何使用前进按钮浏览JavaFx浏览器以及打开包含所有超链接的列表的按钮？

1 个答案: