本例要解决的问题是：成绩按优良中差分组。
一，新建一个基于对话框的BCG工程，单ChengJiGridCtrl。
二，新增CChengJiGridCtrl类，派生于网格控件。头文件如下：
class CChengJiGridCtrl : public CBCGPGridCtrl
{
public:
CChengJiGridCtrl();
virtual ~CChengJiGridCtrl();
virtual int CompareGroup (const CBCGPGridRow* pRow1, const CBCGPGridRow* pRow2, int iColumn);
virtual CString GetGroupName (int nGroupCol, CBCGPGridItem* pItem);
//{{AFX_MSG(CColorGridCtrl)
afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
源文件如下：
BEGIN_MESSAGE_MAP(CChengJiGridCtrl, CBCGPGridCtrl)
//{{AFX_MSG_MAP(CColorGridCtrl)
ON_WM_CREATE()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
CChengJiGridCtrl::CChengJiGridCtrl()
{
}
CChengJiGridCtrl::~CChengJiGridCtrl()
{
}
int CChengJiGridCtrl::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CBCGPGridCtrl::OnCreate(lpCreateStruct) == -1)
return -1;
EnableMarkSortedColumn (TRUE, FALSE);
EnableHeader (TRUE, BCGP_GRID_HEADER_MOVE_ITEMS | BCGP_GRID_HEADER_SORT);
EnableRowHeader (TRUE);
EnableLineNumbers ();
EnableInvertSelOnCtrl ();
const int nColumns = 2;
InsertColumn (0, "姓名", 80);
InsertColumn (1, "成绩", 80);
//-----------------------
// 以第二列分组
//-----------------------
InsertGroupColumn (0, 1);
_variant_t var[][nColumns] = {
{_T("张三"),(long)92},
{_T("李四"),(long)55},
{_T("王五"),(long)70},
{_T("赵六"),(long)95},
};
const int iRowCnt = sizeof(var)/sizeof(var[0]);
for (int i = 0; i < iRowCnt ; i++)
{
CBCGPGridRow* pRow = CreateRow (GetColumnCount ());
for(int j = 0 ; j < nColumns ; j++)
pRow->GetItem (j)->SetValue (var[i][j]);
AddRow (pRow, FALSE);
}
SetReadOnly ();
AdjustLayout ();
return 0;
}
int GetLeve(long l)
{
if( l >= 90 )
return 4;
if( l >= 80 )
return 3;
if( l >= 70 )
return 2;
if( l >= 60 )
return 1;
return 0;
}
//********************************************************************************
int CChengJiGridCtrl::CompareGroup (const CBCGPGridRow* pRow1, const CBCGPGridRow* pRow2, int /*iColumn*/)
{
ASSERT_VALID (this);
ASSERT_VALID (pRow1);
ASSERT_VALID (pRow2);
long lVal1 = (long) pRow1->GetItem (1)->GetValue ();
long lVal2 = (long) pRow2->GetItem (1)->GetValue ();
return GetLeve(lVal2) - GetLeve(lVal1);
}
//********************************************************************************
CString CChengJiGridCtrl::GetGroupName (int /*iColumn*/, CBCGPGridItem* pItem)
{
ASSERT_VALID (this);
ASSERT_VALID (pItem);
long lVal = (long) pItem->GetValue ();
long lLeve = GetLeve(lVal);
if( 4 == lLeve )
return _T("优");
else if( 3 == lLeve)
return _T("良");
else if( 2 == lLeve )
return _T("中");
else if( 1 == lLeve )
return _T("合格");
return _T("不合格");
}
三，CChengJiGridCtrlDlg类增加变量
CChengJiGridCtrl m_grid;
四，CChengJiGridCtrlDlg::OnInitDialog
CRect r(0,0,300,300);
m_grid.Create(WS_CHILD, r, this, 1);
m_grid.ShowWindow(SW_SHOW);
五，Ctrl+F5查看运行效果。如图：
源码下载：
