CMap使用方法总结

#include <array>

#ifdef _DEBUG
#include <iostream>
#include <fstream>
using std::endl;
#endif

void CMFCApplication1Dlg::OnBnClickedOk()
{
	// TODO: 在此添加控件通知处理程序代码
#ifdef _DEBUG
	std::ofstream  ofs("log.txt");
#endif

	// 使用SetAt()初始化
	typedef CMap<CString, CString, CString, CString> MAP_EMPLOYEE;
	MAP_EMPLOYEE map_employee;
	std::array<CString, 3> employee_id{"100","108","120"};
	std::array<CString, 3>employee_name{_T("shihuan"), _T("lipeng"), _T("tianjunhong")};
	for (auto i=0; i!=employee_id.size(); ++i)
	{
		map_employee.SetAt(employee_id[i], employee_name[i]);
	}

	// 使用POS遍历
	POSITION pos = map_employee.GetStartPosition();
	while (pos)
	{
		CString key = 0;
		CString value;
		map_employee.GetNextAssoc(pos, key, value);
#ifdef _DEBUG
		ofs << key.GetString() << " " << value.GetString() << endl;
#endif
	}

	// 使用CPair* 遍历
	auto p = map_employee.PGetFirstAssoc();
	while (p != NULL)
	{
#ifdef _DEBUG
		ofs << p->key.GetString() << " " << p->value.GetString() << endl;
#endif
		p = map_employee.PGetNextAssoc(p);
	}

#ifdef _DEBUG
	ofs.close();
#endif

	CString value;
	BOOL ret;
	ret = map_employee.Lookup("100", value);   // 查找：未找到返回0
	assert(0 == ret);
	ret = map_employee.RemoveKey("100");       // 删除：不存在返回0
	ASSERT(0 != ret);
	map_employee.RemoveAll();                // 清空

	CDialogEx::OnOK();
}