对于那些寻找答案的人,请将其放入初始化代码中：

var treeControl = new dijit.Tree({
    model: treeModel,expandAll: function() {
        // summary:
        //     Expand all nodes in the tree
        // returns:
        //     Deferred that fires when all nodes have expanded
 
        var _this = this;
 
        function expand(node) {
            _this._expandNode(node);
 
            var childBranches = dojo.filter(node.getChildren() || [],function(node) {
                return node.isExpandable;
            });
 
            var def = new dojo.Deferred();
            defs = dojo.map(childBranches,expand);
        }
        return expand(this.rootNode);
    }
});

至少,这对我有用.你可以用collapseAll()做同样的事情,你只需要切换_this._expandNode(node); with _this._collapseNode(node);