0

我必须定义一个名为“路径”的变量，如 ActionListener 内的代码中所示......但我无法在 actionPerformed 方法之外访问“路径”变量！它在方法之外变为空......我如何访问这个变量？！

button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {

            System.out.println("Search " + textField.getText()
                    + " in Project");

            try {
                System.out.println(project.members().length);
                IResource[] ires = project.members();
                String path = "";
                String findResult = "notFound";
                for (int len = 0; len < ires.length; len++) {
                    if (!(path = loopInFolders(project, ires[len],
                            textField.getText())).equals("")) {
                        System.out.println("found at :" + path);
                        findResult = "found";

                        showResultBox(findResult, path);

                        break;
                    }
                }

                if (path.equals("")) {
                    showResultBox(findResult, path);
                }
            } catch (CoreException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }


        }
    });

即使我使用 getter 和 setter 将变量定义为类中的全局变量..但是该变量不会保留它在 actionPerformed 中的值！只有在 Listener 内部才有我想要的正确值......我想在其他方法中使用这个值，但它在那里变成了 null！

这是我的课！我想在execute方法中访问path变量，这个变量会在createOutput方法里面填写actionListener，但是在actionListener外面总是null！

public class FindHandler extends AbstractHandler {

private String path;

@Override
public Object execute(ExecutionEvent event) throws ExecutionException {

    Shell shell = HandlerUtil.getActiveShell(event);
    ISelection sel = HandlerUtil.getActiveMenuSelection(event);

    IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
    IProject project = root.getProject(sel.toString()
            .substring(1, sel.toString().indexOf(" ")).trim());
    System.out.println("selected folder "
            + sel.toString().substring(1, sel.toString().indexOf(" "))
                    .trim());



    createOutput(shell, project);

    if (path != null) {
        System.out.println("Pathhhh***444"+ path);
        IPath iPath = new Path(path);
        IFile file = project.getFile(iPath);
        System.out.println("test file*****" + file.getName());

        file = ResourcesPlugin.getWorkspace().getRoot()
                .getFileForLocation(iPath);

        ISelection selection = new StructuredSelection(file);

        IViewReference[] views = PlatformUI.getWorkbench()
                .getActiveWorkbenchWindow().getActivePage()
                .getViewReferences();
        PlatformUI.getWorkbench().getActiveWorkbenchWindow()
                .getActivePage().resetPerspective();

        for (IViewReference view : views) {
            if ("org.eclipse.jdt.ui.PackageExplorer".equals(view.getId())) {
                IViewPart pExplorer = view.getView(true);
                pExplorer.getViewSite().getSelectionProvider()
                        .setSelection(selection);
                break;
            }
        }
    }

    return null;
}

private void createOutput(Shell shell, final IProject project) {

    // Creating the window with a textBox and two buttons of 'Search' and
    // 'Cancel'
    System.out.println(project.getLocation());
    final JTextField textField = new JTextField();
    final JFrame frame = new JFrame("Search File");
    frame.setLayout(null);
    frame.setSize(350, 250);
    frame.setLocation(350, 250);
    JLabel label = new JLabel("Enter File Name:");
    label.setSize(120, 20);
    label.setLocation(20, 25);
    textField.setSize(150, 20);
    textField.setLocation(150, 25);
    frame.getContentPane().add(textField);
    frame.getContentPane().add(label);
    JButton button = new JButton("Search");
    button.setSize(100, 30);
    button.setLocation(70, 100);
    button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {

            System.out.println("Search " + textField.getText()
                    + " in Project");

            try {
                System.out.println(project.members().length);
                IResource[] ires = project.members();
                path = "";
                String findResult = "notFound";
                for (int len = 0; len < ires.length; len++) {
                    if (!(path = loopInFolders(project, ires[len],
                            textField.getText())).equals("")) {
                        System.out.println("found at :" + path);
                        findResult = "found";

                        showResultBox(findResult, path);

                        break;
                    }
                }

                if (path.equals("")) {
                    showResultBox(findResult, path);
                }
            } catch (CoreException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }


        }
    });
    frame.getContentPane().add(button); // Adds Button to content pane of
                                        // frame
    JButton button_2 = new JButton("Cancel");
    button_2.setSize(100, 30);
    button_2.setLocation(180, 100);
    button_2.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO Auto-generated method stub
            frame.dispose();
        }
    });
    frame.getContentPane().add(button_2);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);

    System.out.println("Pathhhh***333"+ path);

}


public String loopInFolders(IProject project, IResource ires,
        String fileName) {

    if (ires.getName().equals(fileName)) {
        return ires.getLocation().toString();
    } else {
        System.out.println(ires.getName());
        IFolder secondFolder = null;
        try {
            secondFolder = project.getFolder(ires.getName());
            System.out.println(secondFolder.members().length);
            if (secondFolder.members().length > 0) {
                IResource[] ires1 = secondFolder.members();
                for (int i = 0; i < ires1.length; i++) {
                    if (!loopInFolders(project, ires1[i], fileName).equals(
                            ""))
                        return ires1[i].getLocation().toString();
                }
            }
        } catch (Exception ex) {
        }
    }
    return "";

}

public void showResultBox(String findResult, String path) {

    if (findResult.equals("notFound")) {

        final JFrame frame = new JFrame("File Not Found");
        frame.setLayout(null);
        frame.setSize(350, 250);
        frame.setLocation(350, 250);
        JLabel label = new JLabel("There is no such file in the project!");
        label.setSize(600, 20);
        label.setLocation(20, 25);

        frame.getContentPane().add(label);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);

    } else {

        System.out.println("Pathhhh***111"+ path);

        final JFrame frame = new JFrame("File Found");
        frame.setLayout(null);
        frame.setSize(350, 250);
        frame.setLocation(350, 250);
        JLabel label = new JLabel("File is found at: " + path);
        label.setSize(600, 20);
        label.setLocation(20, 25);

        frame.getContentPane().add(label);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);

    }

}

}

4

3 回答 3

3 
    // make path a global variable
    String path;


    // if you are trying to access path in another class,
    // make sure you have a getter method like 
    public String getPath() {
       return this.path;
    }

    button.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {

        System.out.println("Search " + textField.getText()
                + " in Project");

        try {
            System.out.println(project.members().length);
            IResource[] ires = project.members();
            path = "";
            String findResult = "notFound";
            for (int len = 0; len < ires.length; len++) {
                if (!(path = loopInFolders(project, ires[len],
                        textField.getText())).equals("")) {
                    System.out.println("found at :" + path);
                    findResult = "found";

                    showResultBox(findResult, path);

                    break;
                }
            }

            if (path.equals("")) {
                showResultBox(findResult, path);
            }
        } catch (CoreException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }


    }
});
于 2013-02-05T01:07:35.780 回答
2

您的问题也可能是您使用的是 JFrame 而不是模态 JDialog。您的 execute 方法创建一个窗口（上面提到的 JFrame），显示该窗口，然后在用户有机会与新窗口交互之前立即尝试使用 path 变量，因此 path 为空是有意义的。

为了防止这种情况发生，要停止执行方法的执行，直到用户处理了窗口并按下了键 JButton，再次不要显示 JFrame，而是显示模态的 JDialog。如果这样做，当对话框设置为可见时，调用代码将被置于“保持”状态，直到对话框不再可见，此时幸运路径不会为空。

于 2013-02-05T02:09:35.017 回答
2

声明一个名为 的类级别字段path。在您的ActionListener中，不要再次重新声明它，只需为其分配您需要的新值。

public class MyClass {
    private String path;

    public MyClass() {
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                path = "";                
                //....//
            }
        }
    }
}

显然，这是一个简化的示例，您的实现可能会有所不同......

于 2013-02-05T01:04:23.883 回答