链表表示的多叉树如何存入文件??

[xu_ls]

树的接点为
struct Node{
CString str;
Node *pnode[5]
}
指针可能为空; 如何写入文件,又从文件读取?请各位大侠指教!!

[xu_ls]

用序列化的方法，我还没试。不知不用这种方法该怎么办？

[rayyang2000]

直接写CString是不行的,我以前也碰到过,还是转换成char吧!

[songshi]

如果你在MFC中可以用序列化技术有一点点麻烦主要是内存分配等方面的
要例子和我联系。

[songshi]

直接写CString是可以的！（在存储时将其大小GetLength()也一同存进去，
在读取时先读大小，之后设置CString大小之后读！！！

[xu_ls]

谢谢楼上几为的指教。但指针部分怎么存储呢？

[编程浪子]

我说说我的实现

//是与CTreeNode相匹配的“备忘录”,CTreeNode是一个树状结构的复合类（就是多叉树了）
BOOL CMemento::SaveToFile(CFile &file)
{
DWORD len = m_strName.GetLength() + 1;
file.Write(&len, sizeof(len));
file.Write(m_strName.GetBuffer(len), len);
m_strName.ReleaseBuffer();
return TRUE;
}

BOOL COpenCmd::Execute(CString filename, CTreeNode* pRoot)
{
CFile file;
if(!file.Open(filename, CFile::modeRead))
{
m_strError = _T("找不到文件：") + filename;
return FALSE;
}

BOOL ret = Execute(file, pRoot);
file.Close();
return ret;
}

BOOL COpenCmd::Execute(CFile& file, CTreeNode* pRoot)
{
CTreeNode* pNode;
CQueue queue;
CMemento* pMemo;
DWORD type, count;

file.Read(&count, sizeof(DWORD));
pRoot->SetParam(count);
if(count) queue.Add(pRoot);
while(!queue.IsEmpty())
{
file.Read(&type, sizeof(DWORD));
switch(type)
{
case ID_TREENODE:
pNode = new CTreeNode(_T(""));
break;
case ID_GROUPNODE:
pNode = new CGroupNode(_T(""));
break;
case ID_USERNODE:
pNode = new CUserNode(_T(""));
break;
case ID_POLICYNODE:
pNode = new CPolicyNode(_T(""));
break;
case ID_ACCOUNTNODE:
pNode = new CAccountNode(_T(""));
break;
}

file.Read(&count, sizeof(DWORD));
pNode->SetParam(count);
if(count) queue.Add(pNode);
static_cast<CTreeNode*>(queue.Head())->Add(pNode);

pMemo = pNode->CreateMemento();
pMemo->LoadFromFile(file);
pNode->SetMemento(pMemo);
delete pMemo;

if(static_cast<CTreeNode*>(queue.Head())->GetCount() >= static_cast<CTreeNode*>(queue.Head())->GetParam())
queue.Remove();
}

return TRUE;
}


BOOL CSaveCmd::Execute(CString filename, CTreeNode* pRoot)
{
CFile file;
if(!file.Open(filename, CFile::modeCreate|CFile::modeWrite))
{
m_strError = _T("文件打开出错：") + filename;
return FALSE;
}

BOOL ret = Execute(file, pRoot);
file.Close();
return ret;
}

BOOL CSaveCmd::Execute(CFile& file, CTreeNode* pRoot)
{
DWORD count, type;
CMemento* pMemo;

CExtentIterator i(pRoot);
count = pRoot->GetCount();
file.Write(&count, sizeof(count));
for(i.First(); !i.IsDone(); i.Next())
{
type = i.CurrentItem()->GetType();
file.Write(&type, sizeof(type));
count = i.CurrentItem()->GetCount();
file.Write(&count, sizeof(count));
pMemo = i.CurrentItem()->CreateMemento();
i.CurrentItem()->GetMemento(pMemo);
pMemo->SaveToFile(file);
delete pMemo;
}

return TRUE;
}