openlaszlo添另删除树节点

1. <canvas debug="true" fontsize="12">   
       <include href="lz/tree.lzx"/>   
       <dataset name="treedata">   
           <root>   
               <project name="演示方案" isleaf="false">   
                   <scheme name="业务模型一" isleaf="false">   
                       <item name="业务协作流程图" isleaf="true"/>                    
                       <item name="组织机构图" isleaf="true"/>                      
                   </scheme>   
                   <scheme name="业务模型二" isleaf="false">   
                       <item name="业务协作流程图" isleaf="true"/>                    
                       <item name="组织机构图" isleaf="true"/>                          
                   </scheme>   
               </project>      
               <project name="视频" isleaf="false">   
                   <scheme name="视频分类一" isleaf="false">   
                       <item name="视频一" isleaf="true"/>                    
                   </scheme>   
                   <scheme name="视频分类二" isleaf="false">   
                       <item name="视频一" isleaf="true"/>                    
                   </scheme>   
               </project>   
               <project name="图片" isleaf="false">   
                   <scheme name="图片分类一" isleaf="false">   
                       <item name="图片一" isleaf="true"/>                    
                   </scheme>   
                   <scheme name="图片分类二" isleaf="false">   
                       <item name="图片一" isleaf="true"/>                    
                   </scheme>   
               </project>   
           </root>         
       </dataset>   
       <handler name="oninit">   
           canvas.treecontainer.projecttree.datapath.setPointer(treedata.childNodes[0]);    
       </handler>   
       <!--*** save the selected item ***-->   
       <attribute name="selecteditem" value="null"/>   
       <button name="adddir" x="0" y="4" text="Add Dir" height="24">   
           <handler name="onclick">   
               if(canvas.selecteditem==null){    
                  var projectnode = new LzDataElement('project');    
                  projectnode.setAttr('name','NEW DIR');    
                  projectnode.setAttr('isleaf',false);    
                  canvas.treecontainer.projecttree.datapath.p.appendChild(projectnode);    
               }    
           </handler>   
       </button>   
       <button name="deldir" x="80" y="4" text="Del Dir" height="24">   
           <handler name="onclick">   
               if(canvas.selecteditem!=null){    
                   canvas.selecteditem.deleteNode();    
                   canvas.selecteditem = null;    
               }    
           </handler>   
       </button>   
       <view name="treecontainer" x="10" y="30" width="200" height="400" bgcolor="#F5F5F5" clip="true">   
           <tree name="projecttree" text="分类目录" datapath="" isleaf="false" open="true">   
               <tree datapath="*"  text="$path{'@name'}" xindent="20" y="18" closesiblings="false" expander="lztree_plusminus_rsc" isleaf="$path{'@isleaf'}">   
                   <handler name="onclick">   
                       canvas.selecteditem =this.datapath;    
                   </handler>   
               </tree>   
           </tree>   
           <scrollbar/>   
       </view>     
   </canvas>

转载:http://lwz7512.iteye.com/blog/115236