[英]How to access components of one JPanel to another JPanel
我有一个扩展JFrame的gui类。 我分离了JPanels以提高代码的可读性。 我从顶部面板定义了组合框,我想在中央面板中访问它的选定项。 我的中心面板是一个可单击的网格面板。 如何从BoxListener事件中的组合框访问选定的项目?
我的代码在这里:
//Gui ==================================================
public class Gui extends JFrame {
final int WINDOW_WIDTH = 1000; // Window width in pixels
final int WINDOW_HEIGHT = 800; // Window height in pixels
private TopPanel topPanel;
private CenterPanel centerPanel;
public SchedulerGui() {
// Display the title
setTitle("Class Scheduler");
setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
// specify action for the close button
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Create border layout
setLayout(new BorderLayout());
// create the custom panels;
topPanel = new TopPanel();
centerPanel = new CenterPanel(15,7);
// Add it to the content pane
add(topPanel, BorderLayout.NORTH);
add(centerPanel, BorderLayout.CENTER);
setVisible(true);
}
public static void main(String args[]) {
new Gui();
}
}
//top panel =====================================================
public class TopPanel extends JPanel {
JLabel labelCurrentStatus;
// create combo boxes
public JComboBox nameBox;
String[] listNameBox = { "Select Box”, “Box1”, “Box2”, “Box3”};
String selectedNameBox = "";
public TopPanel() {
nameBox = new JComboBox(listNameBox);
// Register an action listener
nameBox.addActionListener(new ComboBoxListener());
// add the combo boxes into the content pane
add(nameBox);
}
private class ComboBoxListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
selectedNameBox = (String) nameBox.getSelectedItem();
labelCurrentStatus.setText(selectedNameBox);
}
}
}
//center panel ================================================
// creates panel grids that is clickable
public class CenterPanel extends JPanel {
public CenterPanel(int row, int col) {
setLayout(new GridLayout(row, col));
setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
JPanel pan = new JPanel();
pan.setEnabled(true);
pan.setBackground(Color.WHITE);
pan.setPreferredSize(new Dimension(3, 3));
pan.setBorder(BorderFactory.createLineBorder(Color.BLACK));
// an exception to not click the top row and most left column headers
if (i != 0 && j != 0) {
pan.addMouseListener(new BoxListener()); // add a mouse listener to make the panels clickable
}
// set names for each panel for later use
pan.setName("PANEL_" + i + "_" + j);
add(pan);
}
}
}
//Class that defines what happens when a panel is clicked
public static class BoxListener extends MouseAdapter
{
public void mouseClicked(MouseEvent me)
{
JPanel clickedBox =(JPanel)me.getSource();
clickedBox.setBackground(Color.RED);
// insert here the code defining what happens when a grid is clicked.
// Need to access the value of the selected item from the combo box
}
}
}
好吧,我认为您遇到了这个问题,因为您的设置存在缺陷。 我看到的唯一方法是在该“顶”面板类中创建一个GetSelectedNameBox()方法,并在“中心”面板类中创建一个set方法。
因此,在您的Gui课堂中,您将执行以下操作:
字符串temp = topPanel.getSelectedNamebox();
然后您将要做centerPanel.setXXXX(temp);
您会看到,为了通过拆分内容来创建更具可读性的代码,可能会使可读性变差。 此外,这不是对getter和setter的正确使用。
我将重新配置,并将所有不同的JPanels放在同一类中。 我还将重点介绍为您的actionListeners使用匿名类,而不是内部类。 这将大大缩短您的代码。 并摆脱所有空白行:P
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.