从另一个类中删除jPanel(removing jPanel from another class)

从另一个类中删除jPanel(removing jPanel from another class)

这是场景：我创建了一个可以删除或隐藏主面板内的JPanel的函数，但是如果从另一个类调用它，它将无法工作。

功能是：

public void hideLoginPanel(){ mainPanel.removeAll(); mainPanel.repaint(); }

我可以在这里设置任何类似设置变量值的东西，但是删除mainPanel中的JPanel将不起作用。

这是我正在调用函数的另一个类的代码：

public class logService{ private MainFrame frame = new MainFrame(); private static logService dataService; public static logService getService() { if (dataService == null) { dataService = new logService(); } return dataService } public void removePanel(){ frame.hideLoginPanel // here's where I called the function } }

Here's the scenario: I created a function that can remove or hide the JPanel inside the main panel but if calling it from another class, it won't work.

The function was:

public void hideLoginPanel(){ mainPanel.removeAll(); mainPanel.repaint(); }

I can set anything like setting variable values here but removing the JPanel inside the mainPanel won't work.

Here's the code from another class where I'm calling the function:

public class logService{ private MainFrame frame = new MainFrame(); private static logService dataService; public static logService getService() { if (dataService == null) { dataService = new logService(); } return dataService } public void removePanel(){ frame.hideLoginPanel // here's where I called the function } }

最满意答案

通过查看您的代码，我假设您已经使用代码private MainFrame mainFrame = new MainFrame();创建了MainFrame的新对象private MainFrame mainFrame = new MainFrame();

相反，您应该将此对象传递给您调用hideLoginPanel()另一个类。 对象可以在构造函数中传递。 看看这两个类：

class MainFrame extends JFrame { public MainFrame() { this.setLayout(new BorderLayout()); this.setBounds(50, 50, 200, 300); this.setVisible(true); JPanel jp = new JPanel(); jp.setBackground(Color.BLUE); this.add(jp, BorderLayout.CENTER); LogService logService = new LogService(this); // This object should be used in your control where you want clear panel //logService.removePanel(); // Comment and uncomment this line to see the difference. Change in blue color } public void hideLoginPanel() { this.removeAll(); this.repaint(); } public static void main(String args[]) { new MainFrame(); } } class LogService { private MainFrame mainFrame; public LogService(MainFrame mainFrame) { this.mainFrame=mainFrame; } public void removePanel(){ mainFrame.hideLoginPanel(); // here's where I called the function } }

By looking at your code i assume you have created a new object of MainFrame by using code private MainFrame mainFrame = new MainFrame();

Instead you should pass this object to another class from where you are calling mehtod hideLoginPanel(). Object can be passed in constructor. Look at these two classes:

class MainFrame extends JFrame { public MainFrame() { this.setLayout(new BorderLayout()); this.setBounds(50, 50, 200, 300); this.setVisible(true); JPanel jp = new JPanel(); jp.setBackground(Color.BLUE); this.add(jp, BorderLayout.CENTER); LogService logService = new LogService(this); // This object should be used in your control where you want clear panel //logService.removePanel(); // Comment and uncomment this line to see the difference. Change in blue color } public void hideLoginPanel() { this.removeAll(); this.repaint(); } public static void main(String args[]) { new MainFrame(); } } class LogService { private MainFrame mainFrame; public LogService(MainFrame mainFrame) { this.mainFrame=mainFrame; } public void removePanel(){ mainFrame.hideLoginPanel(); // here's where I called the function } }