java JavaFX 文本字段事件处理程序

JavaFX TextField EventHandler

提问by Alexis Tyler

Currently I have a TextField which is my address bar and a WebView which is my page. When I click ented the TextField doesn't seem to do anything. It's meant to run the loadPage method and set to page to load whatever the user entered into the address bar. Any help would be appreciated.

目前我有一个 TextField 是我的地址栏，还有一个 WebView 是我的页面。当我点击进入时，TextField 似乎没有做任何事情。它意味着运行 loadPage 方法并设置为 page 以加载用户在地址栏中输入的任何内容。任何帮助，将不胜感激。

package javafx_webview;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.StackPane;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class Main extends Application {

    WebEngine myWebEngine;

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

    public void start(Stage primaryStage) {
        primaryStage.setTitle("Platinum v1");

        TextField addressBar = new TextField();

        addressBar.setOnAction(new EventHandler<ActionEvent>() {
            public void handle(ActionEvent event) {
                loadPage(event.toString());
            }
        });

        WebView myBrowser = new WebView();
        myWebEngine = myBrowser.getEngine();

        StackPane root = new StackPane();
        root.getChildren().add(myBrowser);
        root.getChildren().add(addressBar);
        primaryStage.setScene(new Scene(root, 640, 480));
        primaryStage.show();
    }

    private void loadPage(String url) {
        try {
            myWebEngine.load(url);
        } catch (Exception e) {
            System.out.println("The URL you requested could not be found.");
        }
    }
}

回答by jewelsea

Get the url to load from the textof the address bar, not the toStringof the action event on the address bar.

获取要从text地址栏加载的 url ，而不是地址栏toString上的操作事件。

final TextField addressBar = new TextField();
addressBar.setOnAction(new EventHandler<ActionEvent>() {
  public void handle(ActionEvent event) {
    myWebEngine.load(addressBar.getText());
  }
});

Also the load is asynchronous, so your exception handler won't work. You need to monitor's the webengine loadworker's exception property to get exceptions from the engine. Also note that a url not found is not necessarily an exception which would be reported, instead a web server will usually return a page for a http 404 error.

此外，负载是异步的，因此您的异常处理程序将无法工作。您需要监控 webengine loadworker 的异常属性以从引擎获取异常。另请注意，未找到 url 不一定是会报告的异常，而是 Web 服务器通常会返回一个页面以显示 http 404 错误。

Here is a working sample:

这是一个工作示例：

import javafx.application.Application;
import javafx.beans.value.*;
import javafx.event.*;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.VBox;
import javafx.scene.web.*;
import javafx.stage.Stage;

public class Main extends Application {
  private WebEngine myWebEngine;

  public void start(Stage stage) {
    stage.setTitle("Platinum v1");

    final TextField addressBar = new TextField();

    addressBar.setOnAction(new EventHandler<ActionEvent>() {
      public void handle(ActionEvent event) {
        myWebEngine.load(addressBar.getText());
      }
    });

    WebView myBrowser = new WebView();
    myWebEngine = myBrowser.getEngine();
    myWebEngine.getLoadWorker().exceptionProperty().addListener(new ChangeListener<Throwable>() {
      @Override public void changed(ObservableValue<? extends Throwable> observableValue, Throwable oldException, Throwable exception) {
        System.out.println("WebView encountered an exception loading a page: " + exception);
      }
    });

    VBox root = new VBox();
    root.getChildren().setAll(
        addressBar,
        myBrowser
    );
    stage.setScene(new Scene(root));
    stage.show();
  }

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