当前位置：首页 > news >正文

JavaFX之WebView超详细解析！

news 来源：原创 2024/5/8 23:19:48

JavaFX WebView

JavaFX教程 - JavaFX WebView

JavaFX提供了一个GUI WebView(javafx.scene.web.WebView)节点，以将HTML5内容呈现到场景图形上。

WebView节点是一个小型浏览器。

我们可以使用以下代码加载网页并显示它。

WebView browser = new WebView();
WebEngine webEngine = browser.getEngine();
webEngine.load("http://mySite.com");

完整的源代码

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Worker;
import javafx.concurrent.Worker.State;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {
  @Override
  public void start(final Stage stage) {
    stage.setWidth(400);
    stage.setHeight(500);
    Scene scene = new Scene(new Group());


    final WebView browser = new WebView();
    final WebEngine webEngine = browser.getEngine();

    ScrollPane scrollPane = new ScrollPane();
    scrollPane.setContent(browser);

    webEngine.getLoadWorker().stateProperty()
        .addListener(new ChangeListener<State>() {
          @Override
          public void changed(ObservableValue ov, State oldState, State newState) {

            if (newState == Worker.State.SUCCEEDED) {
              stage.setTitle(webEngine.getLocation());
            }

          }
        });
    webEngine.load("http://www.w3cschool.cn");

    scene.setRoot(scrollPane);

    stage.setScene(scene);
    stage.show();
  }

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

上面的代码生成以下结果。

null

WebEvents

JavaFX Web API也遵循事件驱动的编程模型。

网页中的以下JavaScript将弹出一个包含浏览器窗口消息的警报对话框。

<script>
alert("JavaFX is  Awesome");
</script>

当在JavaFX WebView节点中执行代码时，不会弹出本机对话框窗口。但是，OnAlert事件作为javafx.scene.web.WebEvent对象引发。

我们可以处理这些事件。要设置处理程序，请使用带有类型为WebEvent的入站参数的setOnAlert()方法。

    browser.getEngine().setOnAlert((WebEvent<String> wEvent) -> {
      System.out.println("Alert Event  -  Message:  " + wEvent.getData());
    });

完整的源代码

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebEvent;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {
  @Override
  public void start(final Stage stage) {
    stage.setWidth(400);
    stage.setHeight(500);
    Scene scene = new Scene(new Group());

    final WebView browser = new WebView();
    final WebEngine webEngine = browser.getEngine();

    ScrollPane scrollPane = new ScrollPane();
    scrollPane.setContent(browser);

    browser.getEngine().setOnAlert((WebEvent<String> wEvent) -> {
      System.out.println("Alert Event  -  Message:  " + wEvent.getData());
    });

    webEngine.load("http://www.w3cschool.cn");

    scene.setRoot(scrollPane);

    stage.setScene(scene);
    stage.show();
  }

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

在事件处理程序中，我们可以决定是否显示一个对话框。

下表显示了从javafx.scene.web.WebEngine WebEvents和Properties触发它们的事件和操作。

SetOn方法	方法属性	描述
setOnAlert()	onAlertProperty()	处理JavaScript警报方法
setOnError()	onErrorProperty()	WebEngine错误处理程序
setOnResized()	onResizedProperty()	JavaScript调整大小处理程序
setOnStatusChanged()	onStatusChanged()	JavaScript状态处理程序
setOnVisibilityChanged()	onVisibilityChangedProperty()	JavaScript窗口可见处理程序
setConfirmHandler()	confirmHandlerProperty()	JavaScript确认窗口

上面的代码生成以下结果。

null

管理网络历史记录

import javafx.application.Application;
import javafx.collections.ListChangeListener;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebEvent;
import javafx.scene.web.WebHistory;
import javafx.scene.web.WebHistory.Entry;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {
  @Override
  public void start(final Stage stage) {
    stage.setWidth(400);
    stage.setHeight(500);
    Scene scene = new Scene(new Group());

    final WebView browser = new WebView();
    final WebEngine webEngine = browser.getEngine();

    ScrollPane scrollPane = new ScrollPane();
    scrollPane.setContent(browser);

    browser.getEngine().setOnAlert((WebEvent<String> wEvent) -> {
      System.out.println("Alert Event  -  Message:  " + wEvent.getData());
    });

    webEngine.load("http://www.w3cschool.cn");

    
    final WebHistory history = webEngine.getHistory();
    history.getEntries().addListener(new 
        ListChangeListener<WebHistory.Entry>() {
            @Override
            public void onChanged(Change<? extends Entry> c) {
                c.next();
                for (Entry e : c.getRemoved()) {
                    System.out.println(e.getUrl());
                }
                for (Entry e : c.getAddedSubList()) {
                    System.out.println(e.getUrl());
                }
            }
        }
    );
             
    history.go(0);
    scene.setRoot(scrollPane);

    stage.setScene(scene);
    stage.show();
  }

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

上面的代码生成以下结果。

null

打印HTML内容

以下代码显示如何从WebEngine进行打印。

    PrinterJob job = PrinterJob.createPrinterJob();
    if (job != null) {
        webEngine.print(job);
        job.endJob();
    }

完整的源代码

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Worker;
import javafx.concurrent.Worker.State;
import javafx.print.PrinterJob;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.layout.VBox;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {
  @Override
  public void start(final Stage stage) {
    stage.setWidth(400);
    stage.setHeight(500);
    Scene scene = new Scene(new Group());

    VBox root = new VBox();

    final WebView browser = new WebView();
    final WebEngine webEngine = browser.getEngine();

    ScrollPane scrollPane = new ScrollPane();
    scrollPane.setContent(browser);

    webEngine.getLoadWorker().stateProperty()
        .addListener(new ChangeListener<State>() {
          @Override
          public void changed(ObservableValue ov, State oldState, State newState) {
            if (newState == Worker.State.SUCCEEDED) {
              PrinterJob job = PrinterJob.createPrinterJob();
              if (job != null) {
                webEngine.print(job);
                job.endJob();
              }
            }
          }
        });
    webEngine.load("http://www.w3cschool.cn");

    root.getChildren().addAll(scrollPane);
    scene.setRoot(root);

    stage.setScene(scene);
    stage.show();
  }

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

使用WebView显示HTML

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.layout.VBox;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage stage) {
        stage.setTitle("HTML");
        stage.setWidth(500);
        stage.setHeight(500);
        Scene scene = new Scene(new Group());

        VBox root = new VBox();     

        final WebView browser = new WebView();
        final WebEngine webEngine = browser.getEngine();

        ScrollPane scrollPane = new ScrollPane();
        scrollPane.setContent(browser);
        webEngine.loadContent("<b>asdf</b>");

        root.getChildren().addAll(scrollPane);
        scene.setRoot(root);

        stage.setScene(scene);
        stage.show();
    }
 
    public static void main(String[] args) {
        launch(args);
    }
}

使用CSS更改WebView背景

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.layout.VBox;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage stage) {
        stage.setTitle("HTML");
        stage.setWidth(500);
        stage.setHeight(500);
        Scene scene = new Scene(new Group());
    
        VBox root = new VBox();     
 
        final WebView browser = new WebView();
        final WebEngine webEngine = browser.getEngine();
        
     
        ScrollPane scrollPane = new ScrollPane();
        scrollPane.setStyle("-fx-background-color: white");
        
        scrollPane.setContent(browser);
        webEngine.loadContent("<b>asdf</b>");
         
        
        root.getChildren().addAll(scrollPane);
        scene.setRoot(root);
 
        stage.setScene(scene);
        stage.show();
    }
 
    public static void main(String[] args) {
        launch(args);
    }
}