所以我现在已经为此工作了 45 分钟,但我似乎无法弄清楚为什么如此简单的事情不起作用。我有一个非常复杂的 GUI,并且已经按照我想要的方式将所有内容都放在布局中,但是当我尝试制作 JCheckBoxes
的 JList
时,它完全没有'不工作。所以我在这里将问题简化为这个测试类,也许我正在做一些非常愚蠢的事情,但这是我的代码:
import java.awt.BorderLayout;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class TestGUI extends JFrame{
public TestGUI(){
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setVisible(true);
setTitle("TEST");
JPanel outside = new JPanel();
add(outside);
outside.setLayout(new BorderLayout());
JList<JCheckBox> checks = new JList<JCheckBox>();
JCheckBox c = new JCheckBox("Check");
checks.add(c);
JScrollPane t = new JScrollPane(checks);
add(t, BorderLayout.CENTER);
pack();
}
public static void main(String[] args) {
new TestGUI();
}
}
当我运行 GUI 时,什么也没有出现...只有空白区域,没有复选框...
最佳答案
- 不必要时不要扩展
JFrame
类。 - 在所有组件都完成之前不要调用
JFrame#setVisible(true)
已添加。 - 对 UI 组件使用 Event-Dispatch-Thread/Intial Thread
- 您在外部添加
JPanel
,然后在其顶部添加JScrollPane
我认为这不是您想做的事?
我可以为您整理一个简短的示例,它使用自定义 ListCellRenderer
在 JList
中呈现 JCheckBox
。它还使用 MouseAdapter
来允许选中和取消选中 JCheckBox
:
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;
import javax.swing.ListSelectionModel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class JListTest {
public JListTest() {
JFrame frame = new JFrame();
frame.setTitle("JList Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initComponents(frame);
frame.pack();
frame.setVisible(true);
}
private void initComponents(JFrame frame) {
String[] strs = {"swing", "home", "basic", "metal"};
final JList checkBoxesJList = new JList(createData(strs));
checkBoxesJList.setCellRenderer(new CheckListRenderer());
checkBoxesJList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
checkBoxesJList.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
int index = checkBoxesJList.locationToIndex(e.getPoint());
CheckableItem item = (CheckableItem) checkBoxesJList.getModel().getElementAt(index);
item.setSelected(!item.isSelected());
Rectangle rect = checkBoxesJList.getCellBounds(index, index);
checkBoxesJList.repaint(rect);
}
});
JScrollPane scrollPane = new JScrollPane(checkBoxesJList);
frame.add(scrollPane, BorderLayout.CENTER);
}
private CheckableItem[] createData(String[] strs) {
int n = strs.length;
CheckableItem[] items = new CheckableItem[n];
for (int i = 0; i < n; i++) {
items[i] = new CheckableItem(strs[i]);
}
return items;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new JListTest();
}
});
}
}
class CheckListRenderer extends JCheckBox implements ListCellRenderer {
public CheckListRenderer() {
setBackground(UIManager.getColor("List.textBackground"));
setForeground(UIManager.getColor("List.textForeground"));
}
@Override
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean hasFocus) {
setEnabled(list.isEnabled());
setSelected(((CheckableItem) value).isSelected());
setFont(list.getFont());
setText(value.toString());
return this;
}
}
class CheckableItem {
private String str;
private boolean isSelected;
public CheckableItem(String str) {
this.str = str;
isSelected = false;
}
public void setSelected(boolean b) {
isSelected = b;
}
public boolean isSelected() {
return isSelected;
}
@Override
public String toString() {
return str;
}
}
引用:
关于java - 尝试将 JCheckBox 放入 GUI 中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12948062/