Problems引用WebEngine

Question

我在试着引用WebEngine

public class ClientArea implements Initializable {

public WebEngine engine;

    @Override
    public void initialize(URL url, ResourceBundle rb) {

        engine = browser.getEngine();
        engine.load("about:blank");
    }
}

对于同一文件中的类(ClientArea.java)

private static class SearchBox extends Region {

        private WebEngine engine; // private or public

        private TextField insertU;
        private Button refreshButton;
        private Button stopButton;
        private Button backButton;
        private Button forwardButton;
        public Button voltarButton;

        public SearchBox() {
        }
}

但这不起作用，那会是什么呢？

Answer 1

也许我不明白你的问题。您希望从嵌套类(SearchBox)访问顶级类(ClientArea)的字段(engine)。

如果嵌套类不是 static，就很容易实现。在这种情况下，内部类保持对外部类的引用(ClientArea.this)，并且可以访问外部类的字段和方法。

public class ClientArea implements Initializable {
    public WebEngine engine;

    @Override
    public void initialize(URL url, ResourceBundle rb) {
        engine = browser.getEngine();
        engine.load("about:blank");
    }

    private class SearchBox extends Region {
        public SearchBox() {
            System.err.println(engine);
        }

        private ClientArea getClientArea() {
            return ClientArea.this;
        }

        private WebEngine getWebEngine() {
            return engine;
        }
     }
}

看看this answer关于静态嵌套类和内部类之间的区别。

The java tutorial on the nested classes.