i used your same code
const node = args.getNode();
const vo = node['data'];
const containerNode = node['childern'];
var ctr = node;
if (ctr.children.length == 0) {
var r = ctr.getBounds();
for (var i = 0; i < 310; i++) {
var child = this.diagram.factory.createContainerNode(r.x, r.y, 50, 10);
child.setText(String(i));
ctr.add(child);
}
this.arrangeContainers(ctr);
node['width'] = node.getBounds().width;
node['height'] = node.getBounds().height;
//this.setOffsetUnFoldedChildNodeHierarchical(node, node.bounds.bottom() + node.captionHeight);
this.diagram.resizeToFitItems();
//return;
}


private arrangeContainers(container) {
        var verticalLayout = new mg.LayeredLayout();
        verticalLayout.multipleGraphsPlacement = mg.MultipleGraphsPlacement.Vertical;

        while (container) {
            if (!container.getFolded())
                container.arrange(verticalLayout);
            container = container.container;
        }
    }
and for diagram setvirtualscroll true space is not showing but order changed

For just i want to check it is working on 3.4 version what i can do now?

Ok i will check but for 100 record it is showing in order if data is large that time this problem occurs,

and one more issue that I am facing after expanding node ,straight link is not working and cascading and default linking is working

Quote:


Enabling VirtualScroll is the only way to handle that. If it's disabled, the canvas element gets as large as diagram.Bounds and relies on parent div's overflow for scrolling. Then at some point (e.g. with 310 nodes arranged vertically) it reaches maximum element size supported by the browser, the Canvas API stops working and the library cannot paint in that 'empty space'. With VirtualScroll enabled, the library keeps the canvas element small and implements custom scrolling.

Quote:


ctr.setBrush("gray") works in our test. Check if you aren't replacing the value from later code / event handler:

It should work with your older version too if you enable VirtualScroll mode -

diagram.setVirtualScroll(true); 

In newer versions that's enabled by default.

Yes, it will work.

Quote:


Check if your app isn't replacing the MindFusion.Drawing.Container class with a custom copy from old code. Otherwise please attach a test project reproducing that.

Quote:


Seeing your nodes are custom-drawn, please verify that with standard ContainerNode rendering. If it works correctly then, check if your custom-drawing code isn't glitching at large Y coordinates. Otherwise please attach a test project reproducing that.

You can delete items just fine in Containers.js example (JsDiagram\Samples\JavaScript), so that comes from some interaction with your code. Let us know what we should change there to see that happen.