[script ui]how to remove item from group

You need to update the panel using:

  palette.layout.layout(true);

var palette = new Window("palette", "yuelili", undefined, { resizeable: true});
palette.orientation = "column";

var group1 = palette.add("group", undefined);
group1.orientation = "row";
group1.preferredSize.height = 0;

var group2 = palette.add("group", undefined);
group2.orientation = "column";

var addButton = group1.add("button", undefined, "add");
addButton.preferredSize.width = 95;

var removeButton = group1.add("button", undefined, "remove all");
removeButton.preferredSize.width = 95;

if (palette instanceof Window) {
  palette.center();
  palette.show();
} else {
  palette.layout.layout(true);
  palette.layout.resize();
}

addButton.onClick = function() {
  var staticText = group2.add("statictext", undefined, undefined);
  staticText.text = "statictext " + group2.children.length;
  staticText.preferredSize.width = 200;
  palette.layout.layout(true)
}

removeButton.onClick = function() {
  while (group2.children.length) {
    group2.remove(group2.children[0]);
  }
  group2.preferredSize.height = 0;
  palette.layout.layout(true)
}