我找了答案，但找不到任何解决方法。我有两个包含字符串的数组列表，这些字符串在用户单击后动态更改，现在创建将显示一个列表中的元素的JTree取决于另一个列表中的某些类型。我有一个问题，因为我总是添加和删除列表中的内容，需要JTree来显示更改。它将正确添加List中的所有元素直到我扩展，之后就不可能更新JTree的内容，至少对我而言。如果我清空我的列表它将显示它已折叠但所有内容仍然显示它已扩展，即使它在控制台中提供childcount为0，如果我在列表中添加一些东西，它将添加它但不会显示它。 所以基本上问题是直观地显示JTree的变化。
public class JSelectedTree extends JPanel{
private JTree selectionTree;
private DefaultTreeModel treeModel;
public DefaultMutableTreeNode point;
public DefaultMutableTreeNode polygon;
public DefaultMutableTreeNode line;
public JSelectedTree() {
initGUI();
}
public void initGUI() {
DefaultMutableTreeNode root = new DefaultMutableTreeNode("root");
point = new DefaultMutableTreeNode("Point");
polygon = new DefaultMutableTreeNode("Polygon");
line = new DefaultMutableTreeNode("Line");
root.add(point);
root.add(polygon);
root.add(line);
treeModel = new DefaultTreeModel(root);
selectionTree = new JTree(root);
selectionTree.setRootVisible(false);
selectionTree.setShowsRootHandles(false);
selectionTree.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
JScrollPane scroll = new JScrollPane(selectionTree);
scroll.setBorder(BorderFactory.createTitledBorder("Selected"));
setLayout(new BorderLayout());
add(scroll, BorderLayout.CENTER);
}
public void resetTree(){
if(!MultiSelectTool.selectedObject.isEmpty()){
polygon.removeAllChildren();
point.removeAllChildren();
line.removeAllChildren();
treeModel.reload();
int n = MultiSelectTool.selectedObject.size();
for(int i = 0; i < n; i++){
if(MultiSelectTool.selectedCoords.get(i).contains("(((")){
DefaultMutableTreeNode child = new DefaultMutableTreeNode(MultiSelectTool.selectedObject.get(i));
treeModel.insertNodeInto(child, polygon, polygon.getChildCount());
}else if(MultiSelectTool.selectedCoords.get(i).contains("((")){
DefaultMutableTreeNode child = new DefaultMutableTreeNode(MultiSelectTool.selectedObject.get(i));
treeModel.insertNodeInto(child, line, line.getChildCount());
}else{
DefaultMutableTreeNode child = new DefaultMutableTreeNode(MultiSelectTool.selectedObject.get(i));
treeModel.insertNodeInto(child, point, point.getChildCount());
}
}
}else{
polygon.removeAllChildren();
point.removeAllChildren();
line.removeAllChildren();
treeModel.reload();
}
}
}
答案 0 :(得分：1)
尝试使用MVC模式，以便更新视图：）
答案 1 :(得分：1)
通过从DynamicTreeDemo中获取一些部分来解决这里是代码，如果有人需要这样的东西
public class JSelectedTree extends JPanel{
static JButton addButton;
public static DynamicTree treePanel;
public DefaultMutableTreeNode point;
public DefaultMutableTreeNode polygon;
public DefaultMutableTreeNode line;
DefaultMutableTreeNode p1, p2, p3;
public JSelectedTree() {
treePanel = new DynamicTree();
populateTree(treePanel);
addButton = new JButton("Add");
addButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if(!MultiSelectTool.selectedObject.isEmpty()){
treePanel.clear();
populateTree(treePanel);
int n = MultiSelectTool.selectedObject.size();
for(int i = 0; i < n; i++){
if(MultiSelectTool.selectedCoords.get(i).contains("(((")){
String child = new String(MultiSelectTool.selectedObject.get(i));
treePanel.addObject(p1,child, true);
}else if(MultiSelectTool.selectedCoords.get(i).contains("((")){
String child = new String(MultiSelectTool.selectedObject.get(i));
treePanel.addObject(p2,child, true);
}else{
String child = new String(MultiSelectTool.selectedObject.get(i));
treePanel.addObject(p3,child, true);
}
}
}else{
treePanel.clear();
populateTree(treePanel);
}
}
});
treePanel.setPreferredSize(new Dimension(200, 200));
add(treePanel, BorderLayout.CENTER);
treePanel.setBorder(BorderFactory.createTitledBorder("Selected"));
}
public void populateTree(DynamicTree treePanel) {
String p1Name = new String("Polygon");
String p2Name = new String("Point");
String p3Name = new String("Line");
p1 = treePanel.addObject(null, p1Name, true);
p2 = treePanel.addObject(null, p2Name, true);
p3 = treePanel.addObject(null, p3Name, true);
}
}
class DynamicTree extends JPanel {
protected DefaultMutableTreeNode rootNode;
protected DefaultTreeModel treeModel;
protected JTree tree;
private Toolkit toolkit = Toolkit.getDefaultToolkit();
public DynamicTree() {
super(new GridLayout(1, 0));
rootNode = new DefaultMutableTreeNode("Root Node");
treeModel = new DefaultTreeModel(rootNode);
tree = new JTree(treeModel);
tree.setEditable(true);
tree.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
tree.setShowsRootHandles(true);
JScrollPane scrollPane = new JScrollPane(tree);
add(scrollPane);
}
/** Remove all nodes except the root node. */
public void clear() {
rootNode.removeAllChildren();
treeModel.reload();
}
/** Remove the currently selected node. */
public void removeCurrentNode() {
TreePath currentSelection = tree.getSelectionPath();
if (currentSelection != null) {
DefaultMutableTreeNode currentNode = (DefaultMutableTreeNode) (currentSelection
.getLastPathComponent());
MutableTreeNode parent = (MutableTreeNode) (currentNode.getParent());
if (parent != null) {
treeModel.removeNodeFromParent(currentNode);
return;
}
}
// Either there was no selection, or the root was selected.
toolkit.beep();
}
public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent,
Object child) {
return addObject(parent, child, false);
}
public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent,
Object child, boolean shouldBeVisible) {
DefaultMutableTreeNode childNode = new DefaultMutableTreeNode(child);
if (parent == null) {
parent = rootNode;
}
// It is key to invoke this on the TreeModel, and NOT DefaultMutableTreeNode
treeModel.insertNodeInto(childNode, parent, parent.getChildCount());
// Make sure the user can see the lovely new node.
if (shouldBeVisible) {
tree.scrollPathToVisible(new TreePath(childNode.getPath()));
}
return childNode;
}
class MyTreeModelListener implements TreeModelListener {
public void treeNodesChanged(TreeModelEvent e) {
DefaultMutableTreeNode node;
node = (DefaultMutableTreeNode) (e.getTreePath().getLastPathComponent());
/*
* If the event lists children, then the changed node is the child of the
* node we've already gotten. Otherwise, the changed node and the
* specified node are the same.
*/
int index = e.getChildIndices()[0];
node = (DefaultMutableTreeNode) (node.getChildAt(index));
System.out.println("The user has finished editing the node.");
System.out.println("New value: " + node.getUserObject());
}
public void treeNodesInserted(TreeModelEvent e) {
}
public void treeNodesRemoved(TreeModelEvent e) {
}
public void treeStructureChanged(TreeModelEvent e) {
}
}
}