在 Java 中獲取 JTree 中所有子節點的總數量?
要獲取 JTree 所有葉子的總數,請對根節點應用 getLeafCount() 方法。假設我們的根節點為“node”,因此要計算葉子數,請使用 -
node.getLeafCount()
以下是一個獲取 JTree 所有葉子的總數的示例 -
package my; import javax.swing.JFrame; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; public class SwingDemo { public static void main(String[] args) throws Exception { JFrame frame = new JFrame("Demo"); DefaultMutableTreeNode node = new DefaultMutableTreeNode("Website"); DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Videos"); DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Tutorials"); DefaultMutableTreeNode node3 = new DefaultMutableTreeNode("QA"); DefaultMutableTreeNode node4 = new DefaultMutableTreeNode("Tools"); node.add(node1); node.add(node2); node.add(node3); node.add(node4); DefaultMutableTreeNode one = new DefaultMutableTreeNode("PHP Videos"); DefaultMutableTreeNode two = new DefaultMutableTreeNode("HTML5 Videos"); DefaultMutableTreeNode three = new DefaultMutableTreeNode("Blockchain Videos"); DefaultMutableTreeNode four = new DefaultMutableTreeNode("Java"); DefaultMutableTreeNode five = new DefaultMutableTreeNode("DBMS"); DefaultMutableTreeNode six = new DefaultMutableTreeNode("CSS"); DefaultMutableTreeNode seven = new DefaultMutableTreeNode("MongoDB"); DefaultMutableTreeNode eight = new DefaultMutableTreeNode("Python QA"); DefaultMutableTreeNode nine = new DefaultMutableTreeNode("jQuery QA"); DefaultMutableTreeNode ten = new DefaultMutableTreeNode("Photo Editing Tool"); node1.add(one); node1.add(two); node1.add(three); node2.add(four); node2.add(five); node2.add(six); node2.add(seven); node3.add(eight); node3.add(nine); node4.add(ten); JTree tree = new JTree(node); for (int i = 0; i < tree.getRowCount(); i++) { tree.expandRow(i); } tree.putClientProperty("JTree.lineStyle", "Angled"); System.out.println("Depth of Tree = " + node.getDepth()); System.out.println("Count of Tree Leaves = " + node.getLeafCount()); tree.setRowHeight(25); frame.add(tree); frame.setSize(600,450); frame.setVisible(true); } }
輸出
將生成以下輸出 -
以下是我們的 JTree -
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