Is it possible to select multiple columns in Virtual Treeview?
I need to add functionality to copy a rectangular selection of nodes and columns, but I can't find any way to actually select multiple columns in a Virtual Treeview (beside toFullRowSelect).
Am I just missing something? And if not, is there a descendant out there with grid-like multicolumn select support?
So after some testing I came up with the following, thanks DiGi for the extra push. DrawSelection won't work with this solution so it needs to be disabled. Since I don't think I'll need to do this again soon I didn't write a descendant.
Set toDisableDrawSelection, toExtendedFocus and toMultiSelect to True.
Declare the following variables/properties somewhere suitable:
StartSelectedColumn: integer;
FirstSelectedColumn: integer;
LastSelectedColumn: integer;
Selecting: boolean;
Update the following events:
OnKeyDown
if (not Selecting) and (Key = VK_SHIFT) then
begin
StartSelectedColumn := vtMain.FocusedColumn;
FirstSelectedColumn := StartSelectedColumn;
LastSelectedColumn := StartSelectedColumn;
Selecting := true;
end;
OnKeyUp
if Key = VK_SHIFT then
Selecting := false;
OnFocusChanged
if Selecting then
begin
if column < StartSelectedColumn then
begin
FirstSelectedColumn := column;
LastSelectedColumn := StartSelectedColumn;
end
else if column > StartSelectedColumn then
begin
FirstSelectedColumn := StartSelectedColumn;
LastSelectedColumn := column
end
else
begin
FirstSelectedColumn := column;
LastSelectedColumn := column;
end;
end
else
begin
StartSelectedColumn := column;
FirstSelectedColumn := column;
LastSelectedColumn := column;
end;
OnBeforeCellPaint
if vtMain.Selected[node] and InRange(column, FirstSelectedColumn, LastSelectedColumn) then
begin
if vtMain.Focused then
TargetCanvas.Brush.Color := vtMain.Colors.FocusedSelectionColor
else
TargetCanvas.Brush.Color := vtMain.Colors.UnfocusedSelectionColor;
TargetCanvas.Brush.Style := bsSolid;
TargetCanvas.FillRect(CellRect);
end;
OnPaintText
if vtMain.Selected[node] and InRange(column, FirstSelectedColumn, LastSelectedColumn) then
begin
if vtMain.Focused then
TargetCanvas.Font.Color := clHighlightText
else
TargetCanvas.Font.Color := vtMain.Font.Color;
end;
You can try enable/add toGridExtensions in TreeOptions.MiscOptions. It enables free moving in columns by cursor keys, but VT still deselect column on leaving. But I'm sure that is possible to "fix" it by custom draw and remembering starting node and column.
还有一点 - 看看OnStateChange事件，也许你可以使用
procedure TSomeForm.VTreeStateChange(Sender: TBaseVirtualTree; Enter,Leave: TVirtualTreeStates);
begin
if tsDrawSelecting in Enter then
begin
// Save position
end;
end;
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