Moving Rows in CListCtrl
This article is very strightfoward but I thought it was a feature that most people could use in their own custom CListCtrls or CListViews.
I had the need in one of my projects to allow the user to rearrange the order of the ListCtrl but I didn't want to allow them to drag and drop. Therefore I came up with this.
代码
BOOL CListCtrlEx::MoveRow(int from, int to)
{
//Can't move to the same place, or from or to a negative index
if(from == to || from < 0 || to < 0)
return FALSE;
//First Copy the row to the new location
if(CopyRow(from, to))
{
//If we have just inserted a row before
//this one in the list, we need to increment
//our index.
if(from > to)
DeleteItem(from + 1);
else
DeleteItem(from);
return TRUE;
}
else
return FALSE;
}
BOOL CListCtrlEx::CopyRow(int from, int to)
{
//Can't move to the same place, or from or to a negative index
if(from == to || from < 0 || to < 0)
return FALSE;
//Copy the row to the new index
InsertItem(to, GetItemText(from, 0));
//If row has been inserted before original
//increment the original
if(from > to)
from++;
//Loop through subitems
for(int i = 1; i < GetColumnCount(); i++)
{
SetItemText(to, i, GetItemText(from, i));
}
return TRUE;
}
{
//Can't move to the same place, or from or to a negative index
if(from == to || from < 0 || to < 0)
return FALSE;
//First Copy the row to the new location
if(CopyRow(from, to))
{
//If we have just inserted a row before
//this one in the list, we need to increment
//our index.
if(from > to)
DeleteItem(from + 1);
else
DeleteItem(from);
return TRUE;
}
else
return FALSE;
}
BOOL CListCtrlEx::CopyRow(int from, int to)
{
//Can't move to the same place, or from or to a negative index
if(from == to || from < 0 || to < 0)
return FALSE;
//Copy the row to the new index
InsertItem(to, GetItemText(from, 0));
//If row has been inserted before original
//increment the original
if(from > to)
from++;
//Loop through subitems
for(int i = 1; i < GetColumnCount(); i++)
{
SetItemText(to, i, GetItemText(from, i));
}
return TRUE;
}
Remember that if you want to move a row one row upwards in the list you can use:
m_List.MoveRow(index, index - 1);
But to move it one row down you need:
m_List.MoveRow(index, index + 2);
This is because if you just enter 'index + 1' as the destination, the new row is inserted immeadiately after the current one. The current one is then deleted so you end up in the same place!
Ahh... Trial and Error is a wonderful thing.