Unlimited add tree node in PB-Continued

Author: Xingda Computer technology company (www.study01job.com) Guo Baoli

Second, add to what position

After an article, we continue to discuss how to determine where to add a node. This is actually a tree-structured traversal problem. The traversal of a tree structure is usually implemented using a recursive program, so this section gives a search by content, traverses the tree structure, and returns the handle of the node if it is equal to the content to be found. The insert completes after the return, using the knowledge described in the previous article to be implemented. The functions are as follows:

/*-----------------------------------------------------------------------------

* Function Name: Long Wf_reader (Long al_handle,string as_target)

* Function: traverse the tree structure to find the node of the specified content.

* Return value: The handle of the node.

* Algorithm Description: Traversing the tree structure, using recursion to complete.

* Date of preparation: 2004.6.26

* Author: da Tong Xing Computer technology Guo Baoli

*----------------------------------------------------------------------------*/

Long Ll_handle

Long Ll_handleold

TreeViewItem Ltvi_item

String Ls_label

String Ls_data

If Tv_1.getitem (al_handle,ltvi_item) =-1 Then return-1

Ls_label=trim (String (Ltvi_item.label))

Ls_data=trim (String (Ltvi_item.data))

If Ls_label = As_target Then

Return Al_handle

Else

Ll_handle = Tv_1.finditem (childtreeitem!,al_handle)

End If

If Ll_handle > 0 Then

If Tv_1.getitem (ll_handle,ltvi_item) =-1 then return 0

Ls_label=trim (String (Ltvi_item.label))

Ls_data=trim (String (Ltvi_item.data))

If Ls_label = As_target Then

Return ll_handle//found the node to add

Else

Return Wf_reader (Ll_handle,as_target)

End If

Else

Ll_handleold = Al_handle

Ll_handle = Tv_1.finditem (nexttreeitem!,ll_handleold)

Do While Ll_handle < 0

Ll_handle = Tv_1.finditem (parenttreeitem!,ll_handleold)

If Ll_handle > 0 Then

Ll_handleold = Ll_handle

Ll_handle = Tv_1.finditem (nexttreeitem!,ll_handleold)

Else

Ll_handle = Tv_1.finditem (nexttreeitem!,ll_handle)

If Ll_handle < 0 Then

Return-1

End If

End If

Loop

If Tv_1.getitem (ll_handle,ltvi_item) =-1 Then return-1

Ls_label=string (Ltvi_item.label)

Ls_data=string (Ltvi_item.data)

If Ls_label = As_target Then

Return ll_handle//found the node to add

Else

Return Wf_reader (Ll_handle,as_target)

End If

End If

Return Ll_handle

invocation example. For example, we put a single-line editor sle_1 on the window, the user enters the content, and clicks the command button ' find ' to call the above function:

String Ls_find

Long Ll_handle

Ls_find = Trim (Sle_1.text)

Ll_handle = Tv_1.finditem (roottreeitem!, 0)

If Ll_handle > 0 Then

Ll_handle = Wf_reader (ll_handle,ls_find)

If Ll_handle > 0 Then

MessageBox (' Find ', String (Ll_handle))

Else

MessageBox (', ' not found ')

End If

End If