java - 如何将列表传递到 Swing 中的初始框架

Question

public Lab7(File file) {
    List<Item> items = null;
    try {
        items = InventoryReader.read(file);
    } catch (ApplicationException e) {
        LOG.error(e.getMessage());
        return;
    }

    EventQueue.invokeLater(new Runnable() {         
        public void run() {
            try {
                for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                    if ("Nimbus".equals(info.getName())) {
                        UIManager.setLookAndFeel(info.getClassName());
                        break;
                    }
                }
            } catch (Exception e) {
                // If Nimbus is not available, use the default.
            }
            try {
                MainFrame frame = new MainFrame(items); // THIS IS WHERE I HAVE TROUBLE
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

背景:我将 MainFrame 的构造函数设置为接受列表。如何在应用程序的 main() 中执行此操作？

我收到错误:

不能引用不同方法中定义的内部类中的非最终变量“items”

错误出现在 MainFrame frame = new MainFrame(items) 我似乎无法将 items 变量传递给 MainFrame 类...为什么会这样？

如何将此变量传递到 MainFrame 框架中？

Answer 1

你有两个选择......

选择一个...

将items列表设为最终列表，以便可以从Runnable上下文中访问它...

public Lab7(File file) {
    final List<Item> items = null; // Make the items final...
    try {
        items = InventoryReader.read(file);
    } catch (ApplicationException e) {
        LOG.error(e.getMessage());
        return;
    }

    EventQueue.invokeLater(new Runnable() {         
        public void run() {
            try {
                for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                    if ("Nimbus".equals(info.getName())) {
                        UIManager.setLookAndFeel(info.getClassName());
                        break;
                    }
                }
            } catch (Exception e) {
                // If Nimbus is not available, use the default.
            }
            try {
                MainFrame frame = new MainFrame(items); // THIS IS WHERE I HAVE TROUBLE
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

选择二...

将items列表移动到Runnable上下文中

public Lab7(File file) {

    EventQueue.invokeLater(new Runnable() {         
        public void run() {
            // Load the items within the content of the runnable...
            List<Item> items = null;
            try {
                items = InventoryReader.read(file);
            } catch (ApplicationException e) {
                LOG.error(e.getMessage());
                return;
            }
            try {
                for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                    if ("Nimbus".equals(info.getName())) {
                        UIManager.setLookAndFeel(info.getClassName());
                        break;
                    }
                }
            } catch (Exception e) {
                // If Nimbus is not available, use the default.
            }
            try {
                MainFrame frame = new MainFrame(items); // THIS IS WHERE I HAVE TROUBLE
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}