我用dynatree.js創建了一個js樹。我有一個很長的等級。該樹顯示負載上擴大。我想樹應該擴大到一個層次。下面是我的代碼dynatree js顯示最初展開的樹

<apex:component controller="TreeViewController"> 
    <apex:attribute name="roleOrUserId" required="true" type="String" assignTo="{!roleOrUserId}" description="Enter Role or User Id to build the hierarchy. Pass null if you are passing JSON data as a parameter" /> 
    <apex:attribute name="selectable" type="Boolean" assignTo="{!selectable}" description="Do you want nodes to be selectable?" /> 
    <apex:attribute name="value" type="String" description="IDs of selected Nodes in CSV format" /> 
    <apex:attribute name="JsonData" type="String" assignTo="{!JsonData}" description="JSON input for the tree component" /> 
    <apex:inputHidden id="selectedKeys" value="{!value}" /> 
    <!--<apex:includeScript value="{!URLFOR($Resource.DynaTree, 'jquery/jquery.js')}" /> --> 
    <apex:includescript value="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.js"/> 
    <apex:includeScript value="{!URLFOR($Resource.DynaTree, 'jquery/jquery-ui.custom.js')}" /> 
    <apex:includeScript value="{!URLFOR($Resource.DynaTree, 'jquery/jquery.cookie.js')}" /> 
    <apex:includeScript value="{!URLFOR($Resource.DynaTree, 'src/jquery.dynatree.js')}" /> 
    <!--<apex:includeScript value="{!$Resource.DynaTreeJs}" /> --> 

    <apex:stylesheet value="{!URLFOR($Resource.DynaTree, 'src/skin/ui.dynatree.css')}" /> 

    <!-- Add code to initialize the tree when the document is loaded: --> 
    <script type="text/javascript"> 
    $.noConflict(); 
    $(document).ready(function() { 
     $(function(){ 
      // Attach the dynatree widget to an existing <div id="tree"> element 
      // and pass the tree options as an argument to the dynatree() function: 
      $("#tree").dynatree({ 
       onActivate: function(node) { 
        // A DynaTreeNode object is passed to the activation handler 
        // Note: we also get this event, if persistence is on, and the page is reloaded. 
        //alert("You activated " + node.data.key); 
       }, 
       persist: false, 
       checkbox: true, 
       generateIds: false, 
       classNames: { 
        checkbox: "dynatree-checkbox", 
        expanded: "dynatree-expanded" 
       }, 
       selectMode: 3, 
       children: {!JsonString}, 
       onSelect: function(select, node) { 
        // Get a list of all selected nodes, and convert to a key array: 
        var selKeys = $.map(node.tree.getSelectedNodes(), function(node){ 
         return node.data.key; 
        }); 
        jQuery(document.getElementById("{!$Component.selectedKeys}")).val(selKeys.join(", ")); 

        // Get a list of all selected TOP nodes 
        var selRootNodes = node.tree.getSelectedNodes(true); 
        // ... and convert to a key array: 
        var selRootKeys = $.map(selRootNodes, function(node){ 
         return node.data.key; 
        }); 
       }, 

      }); 

     }); 

    }); 
    </script> 

    <!-- Add a <div> element where the tree should appear: --> 
    <div id="tree"> </div> 

</apex:component>