webdynpro tree控件使用

1、  首先创建一个TREE控件

2、  在Tree下面创建一个TREE  NODE  TYPE ,node type 是可以继续展开的，而Item type是无法展开的.

3、 创建node.，下面的图是完成的node

创建在node下面创建递归treenode，递归treenode相当于node，node下面的属性在treenode中都有，就相当于一个dode展开后还有一个node下面的属性和node是一样的，一层有一层的。跟node结构一样。

创建属性，其中包括HAS_CHILDREN，它是类型是BOOLEAN。用于控制递归node是否可以展开.

返回到layout设计界面，tree控件的datasource需要绑定刚才建立的NODE

treenode的datasource需要绑定刚才建立的NODE,hasChildren也要绑定node中的hasChildren，iconSource绑定node中的icon，TEXT绑定node中的treetext.

4 、初始方法code：

method WDDOINIT .
  DATA lo_nd_tree TYPE REF TO if_wd_context_node.

  DATA lt_tree TYPE wd_this->Elements_tree.
  DATA ls_tree TYPE wd_this->Element_tree.

  ls_tree-TREETEXT = ''.
  ls_tree-HAS_CHILDREN = abap_TRUE.
  APPEND ls_tree to lt_tree.

  ls_tree-TREETEXT = ''.
  ls_tree-HAS_CHILDREN = abap_TRUE.
  APPEND ls_tree to lt_tree.

  ls_tree-TREETEXT = ''.
  ls_tree-HAS_CHILDREN = abap_TRUE.
  APPEND ls_tree to lt_tree.
  CLEAR ls_tree.

  lo_nd_tree = wd_context->get_child_node( name = wd_this->wdctx_tree ).
  lo_nd_tree->bind_table( new_items = lt_tree set_initial_elements = abap_true ).

  DATA lo_el_2nd TYPE REF TO IF_WD_CONTEXT_ELEMENT.
  CALL METHOD LO_ND_TREE->GET_ELEMENT
    EXPORTING
      INDEX        =               "得到第二个
    RECEIVING
      NODE_ELEMENT = lo_el_2nd.

  DATA lo_nd_2nd_TREENODE TYPE REF TO IF_WD_CONTEXT_node.

  CALL METHOD LO_EL_2ND->GET_CHILD_NODE
    EXPORTING
      NAME       = 'TREENODE'   "递归node
    RECEIVING
      CHILD_NODE = lo_nd_2nd_TREENODE.

  REFRESH lt_tree.

  ls_tree-TREETEXT = '2.1'.
  APPEND ls_tree to lt_tree.

  ls_tree-TREETEXT = '2.2'.
  APPEND ls_tree to lt_tree.

  lo_nd_2nd_TREENODE->bind_table( new_items = lt_tree set_initial_elements = abap_true ).
endmethod.

5、运行效果