update：为新加连接线添加默认 category

src/App.vue

@@ -269,6 +269,18 @@ function addInspector(){
     addProperty.value = false
 }
 
+function addListener(){
+    // 监听连线事件，为所有新添加的线默认加上 "Arrow" 类别
+    myDiagram.addDiagramListener("LinkDrawn", function(e:go.DiagramEvent) {
+        let link = e.subject;
+        let linkDataArray = myDiagram.model.linkDataArray
+        linkDataArray.forEach((item:any)=>{
+            if (item === link.data && !item.category){
+                myDiagram.model.set(item, "category", "Arrow")
+            }
+        })
+    });
+}
 function importData() {
     myDiagram.model = go.Model.fromJson(
         { "class": "GraphLinksModel",
@@ -353,6 +365,7 @@ onMounted(() => {
     importData();
     changeData();
     animateFlow(myDiagram);
+    addListener();
 })
 
 </script>