CListCtrl::SortItemsEx
Sorts the items of the current list-view control by using an application-defined comparison function.
BOOL SortItemsEx(
PFNLVCOMPARE pfnCompare,
DWORD_PTR dwData
);
Parameters
Parameter |
Description |
|---|---|
[in] pfnCompare |
Address of the application-defined comparison function. The sort operation calls the comparison function each time the relative order of two list items needs to be determined. The comparison function must be either a static member of a class or a stand-alone function that is not a member of any class. |
[in] dwData |
Application-defined value passed to the comparison function. |
Return Value
true if this method is successful; otherwise, false.
Remarks
This method changes the index of each item to reflect the new sequence.
The comparison function, pfnCompare, has the following form:
int CALLBACK CompareFunc(LPARAM lParam1, LPARAM lParam2, LPARAM lParamSort);
This message is like LVM_SORTITEMS, except for the type of information passed to the comparison function. In LVM_SORTITEMS, lParam1 and lParam2 are the values of the items to compare. In LVM_SORTITEMSEX, lParam1 is the current index of the first item to compare and lParam2 is the current index of the second item. You can send an LVM_GETITEMTEXT message to retrieve more information about an item.
The comparison function must return a negative value if the first item should precede the second, a positive value if the first item should follow the second, or zero if the two items are equal.
Note
During the sorting process, the list-view contents are unstable. If the callback function sends any messages to the list-view control other than LVM_GETITEM, the results are unpredictable.
This method sends the LVM_SORTITEMSEX message, which is described in the Windows SDK.
Requirements
Header: afxcmn.h
This method is supported in Windows 2000, Windows NT 4.0 with Internet Explorer 5, Windows 98, and later.
Example
The following code example defines a variable, m_listCtrl, that is used to access the current list-view control. This variable is used in the next example.
public:
// Variable used to access the list control.
CListCtrl m_listCtrl;
The following code example demonstrates the SortItemEx method. In an earlier section of this code example, we created a list-view control that displays two columns titled "ClientID" and "Grade" in a report view. The following code example sorts the table by using the values in the "Grade" column.
// The ListCompareFunc() method is a global function used by SortItemEx().
int CALLBACK ListCompareFunc(
LPARAM lParam1,
LPARAM lParam2,
LPARAM lParamSort)
{
CListCtrl* pListCtrl = (CListCtrl*) lParamSort;
CString strItem1 = pListCtrl->GetItemText(static_cast<int>(lParam1), 1);
CString strItem2 = pListCtrl->GetItemText(static_cast<int>(lParam2), 1);
int x1 = _tstoi(strItem1.GetBuffer());
int x2 = _tstoi(strItem2.GetBuffer());
int result = 0;
if ((x1 - x2) < 0)
result = -1;
else if ((x1 - x2) == 0)
result = 0;
else
result = 1;
return result;
}
void CCListCtrl_s2Dlg::OnBnClickedButton1()
{
// SortItemsEx
m_listCtrl.SortItemsEx( ListCompareFunc, (LPARAM)&m_listCtrl );
}