Title: ListView column index from cursor position (i.e. Right Click etc...)
Question: when trying to implement code in the ColumnRightClick event of a TListView all is fine and Column.Index is accurate as long as there is no Horizontal scroll-bar in the TListView, once a Scroll-Bar is in use the Column.Index is NOT the index of the actual column under your mouse cursor, using the code I've attached can guarntee accurate results.
Answer:
{=== Get the Column index of the ListView Column under the cursor ===}
Function GetColumnAtCursor(Const iLvwHwnd:Integer): Integer;
// Using: Windows;
Var i,j,m,scrolPos:Integer;
pt : TPoint;
rct : TRect;
Const LVM_GETCOLUMNWIDTH = 4125;//-- Instead of searching these constants, I've posted them here --\\
HDM_GETITEMCOUNT = 4608;
LVM_GETCOLUMNORDERARRAY = 4155;
//-- Get the ListView's horizontal scroll-bar position --\\
Function GetLvwHzScrolPos(Const lvwHwnd:Integer): Integer;
Var si:TScrollInfo;
begin
si.cbSize := SizeOf(si);
si.fMask := SIF_ALL;
if IsWindow(lvwHwnd) And GetScrollInfo(lvwHwnd, SB_HORZ, si) then
Result := si.nPos
else
Result := 0;
end;
begin
Result := -1;
scrolPos := GetLvwHzScrolPos(iLvwHwnd); //-- Get the ListView horizonatl Scroll-Bar position --\\
GetCursorPos(pt); //-- Get current cursor position --\\
GetWindowRect(iLvwHwnd, rct); //-- Get the ListView position on the screen --\\
i := WindowFromPoint(pt); //-- Get the cloumn header --\\
m := SendMessage(i, HDM_GETITEMCOUNT, 0, 0);//-- Get the columns count --\\
pt.X := Pt.X-rct.Left;//-- Adjust the cursor position to be relative to the control (as opposed to relative to screen) --\\
pt.Y := Pt.Y-rct.Top;
j := scrolPos*-1; //-- Start adding the width of each column from the scrolled position --\\
For i:=0 To m-1 do begin
//-- Get and add the acutal width of each ListView column --\\
j := j+ Integer(SendMessage(iLvwHwnd, LVM_GETCOLUMNWIDTH, i, 0));
//-- Once the width equals to the cursor position the column header is found --\\
if j=(pt.X) then begin
Result := i;
Break;
end;
end;
end;
//---------------------------------------------------------------------\\