DiagramListener not being called?

Question

我正在尝试捕获 TreeExpanded 和 TreeCollapsed 事件，但没有调用各自的侦听器。我按如下方式实现了侦听器：

myDiagram.addDiagramListener("TreeExpanded", function(e) {
console.log(">>>>> STUFF HAPPENED in TreeExpanded");
});
myDiagram.addDiagramListener("TreeCollapsed", function(e) {
console.log(">>>>> STUFF HAPPENED in TreeCollapsed");
});

myDiagram的完整代码如下所示：

myDiagram = $(go.Diagram, "myDiagramDiv",
{
"undoManager.isEnabled": true,
layout: $(go.TreeLayout),
"ChangedSelection": onSelectionChanged
});
function geoFunc(geoname) {
var geo = icons[geoname];
if (geo === undefined) geo = icons["heart"];  // use this for an unknown icon name
if (typeof geo === "string") {
geo = icons[geoname] = go.Geometry.parse(geo, true);  // fill each geometry
}
return geo;
}
myDiagram.nodeTemplate =
$(go.Node, "Auto",
{isTreeExpanded:false},
{doubleClick: function(e, node) {node.expandTree(1);}},
$(go.Shape, "Rectangle",
{ strokeWidth: 2, stroke: colors["gray"],  },
new go.Binding("fill", "color")),
$(go.TextBlock, {stroke:"black",font:"12pt sans-serif",margin:3,wrap: go.TextBlock.WrapDesiredSize},new go.Binding("text", "geo"))

);
// Define a Link template that routes orthogonally, with no arrowhead
myDiagram.linkTemplate =
$(go.Link,
{ routing: go.Link.Orthogonal, corner: 5, toShortLength: -2, fromShortLength: -2 },
$(go.Shape, { strokeWidth: 2, stroke: colors["gray"] })); // the link shape

myDiagram.addDiagramListener("TreeExpanded", function(e) {
console.log(">>>>> STUFF HAPPENED in TreeExpanded");
});
myDiagram.addDiagramListener("TreeCollapsed", function(e) {
console.log(">>>>> STUFF HAPPENED in TreeCollapsed");
});

// Create the model data that will be represented by Nodes and Links
myDiagram.model = new go.GraphLinksModel(
[

如何检测节点树何时展开或折叠，然后调用函数？

Answer 1

调用Node.collapseTree 或 Node.expandTree是一个相对低级的操作。 您的doubleClick事件处理程序不会执行事务(但任何更改都应该执行(，也不会引发任何事件，例如"TreeExpanded">DiagramEvent。

而是调用CommandHandler.expandTree 或 CommandHandler.collapseTree。例如：

{
doubleClick: function(e, node) {
e.diagram.commandHandler.expandTree(node); 
}
},