BCB TreeView & ListView 互动关联问题

我想用C++ Builder弄一个似档案总管这样的方式，点TreeView的父、子节点，ListView就会显示其资料。
我想点"a"，ListView就显示"He"，点"aa"就显示"she"，点"b"，ListView就出现"It" ..
但不管我怎么用，"He""She""It"都会一起出现阿!!!!!
挺头疼的阿 ..
上代码：

void __fastcall TForm1::FormCreate(TObject *Sender)

{

   TTreeNode* node;

   TTreeNode* Nextnode;



   TreeView1->Items->Clear();

   TreeView1->Items->Add(NULL,"Computer");

   node=TreeView1->Items->Item[0];



   TreeView1->Items->AddChild(node,"a" );

   node=TreeView1->Items->Item[1];



   Nextnode=node->getNextSibling();

   TreeView1->Items->AddChild(node,"aa" );

   Nextnode=TreeView1->Items->Item[1]->GetLastChild();



   TreeView1->Items->Add(node,"b");

   Nextnode=TreeView1->Items->Item[0]->GetLastChild();

   TreeView1->Items->AddChild(Nextnode,"bb" );

   TreeView1->Items->AddChild(Nextnode,"bbb" );



}

//--------------------------------------------------------

void __fastcall TForm1::TreeView1Click(TObject *Sender)

{

   ListView1->Items->Clear();

   Application->ProcessMessages();

   Sleep(10);



   TTreeNode* node;

   TTreeNode* Nextnode;

   node=TreeView1->Items->Item[0];

   Nextnode=TreeView1->Items->Item[0]->GetLastChild();

   node = TreeView1 -> Selected;



    switch(node->Level==0)

    {

    case 0: {

    TListItem *pItem=0;

    pItem=ListView1->Items->Add();

    pItem->Caption=String("He");

    }   break;

    case 1:

    break;

    default:;

    }

    switch(node->Level==1)

    {

    case 0: {

    TListItem *pItem=0;

    pItem=ListView1->Items->Add();

    pItem->Caption=String("She");

    }   break;

    case 1:

    break;

    default:;

    }

    switch(node->Level==1)

    {

    case 0: {

    TListItem *pItem=0;

    pItem=ListView1->Items->Add();

    pItem->Caption=String("It");

    }   break;

    case 1:

    break;

    default:;

    }

}