fix(demo): 按钮事件委托绑定——demo_viewer.ui按钮此前零绑定导致点击无响应

wwwroot/demo_viewer.js

@@ -334,3 +334,28 @@
 
   window.demoViewer = demoViewer;
 })();
+
+/* —— 按钮事件委托（demo_viewer.ui 按钮无 script 绑定，按文本路由）—— */
+(function () {
+  var ACT = {
+    '开始演示': function () { window.demoViewer.startDemo(); },
+    '结束演示': function () { window.demoViewer.stopDemo(); },
+    '暂停': function () { window.demoViewer.pauseDemo(); },
+    '继续': function () { window.demoViewer.resumeDemo(); },
+    '编辑实体': function () { window.demoViewer.editEntity(); },
+    '查看属性': function () { window.demoViewer.showAttrs(); },
+    '保存脚本(热加载)': function () { window.demoViewer.hotload(); },
+    '全屏': function () { window.demoViewer.toggleFullscreen(); },
+    '视角:环绕': function () { window.demoViewer.switchCamera('orbit'); },
+    '视角:俯视': function () { window.demoViewer.switchCamera('topdown'); },
+    '视角:第一人称': function () { window.demoViewer.switchCamera('firstperson'); },
+    '加入多人预览': function () { window.demoViewer.joinPresence(); },
+    '离开预览': function () { window.demoViewer.leavePresence(); }
+  };
+  document.addEventListener('click', function (e) {
+    var b = e.target && e.target.closest ? e.target.closest('button') : null;
+    if (!b || !window.demoViewer) return;
+    var txt = (b.textContent || '').trim();
+    if (ACT[txt]) { e.preventDefault(); ACT[txt](); }
+  });
+})();