我正在尝试通过减少执行某些操作所需的点击次数来改进GUI.但是,困扰我的一个VCL组件是TValueListEditor,它包含一个键和值列表,所有这些都由下拉列表控制.选择选项始终需要三次点击,只需要两次：
此时,最上面的行具有焦点,可以使用下拉列表(两次单击)更改值.但是,当用户想要编辑不同的密钥时,他首先必须将焦点更改为该密钥才能使用下拉列表(三次单击).
有没有办法在所有行上显示下拉箭头以防止额外的点击？
这是我想要实现的模型示例：
解决方法
uses
Vcl.Themes;
type
TValueListEditor = class(Vcl.ValEdit.TValueListEditor)
private
procedure DrawDropDownButton(ACol,ARow: Integer; ARect: TRect;
AState: TGridDrawState);
function MouSEOverButton(X: Integer): Boolean;
protected
procedure DrawCell(ACol,ARow: Integer; ARect: TRect;
AState: TGridDrawState); override;
procedure DrawCellHighlight(const ARect: TRect; AState: TGridDrawState;
ACol,ARow: Integer); override;
procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X,Y: Integer); override;
end;
{ TValueListEditor }
type
TInplaceEditListAccess = class(Vcl.Grids.TInplaceEditList);
procedure TValueListEditor.DrawCell(ACol,ARow: Integer; ARect: TRect;
AState: TGridDrawState);
begin
inherited DrawCell(ACol,ARow,ARect,AState);
DrawDropDownButton(ACol,AState);
end;
procedure TValueListEditor.DrawCellHighlight(const ARect: TRect;
AState: TGridDrawState; ACol,ARow: Integer);
var
R: TRect;
begin
R := ARect;
if ItemProps[ARow - FixedRows].HasPickList then
Dec(R.Right,EditList.ButtonWidth);
inherited DrawCellHighLight(R,AState,ACol,ARow);
DrawDropDownButton(ACol,AState);
end;
procedure TValueListEditor.DrawDropDownButton(ACol,ARow: Integer;
ARect: TRect; AState: TGridDrawState);
var
Details: TThemedElementDetails;
begin
if (ACol = 1) and (ARow >= FixedRows) and not (gdFocused in AState) and
ItemProps[ARow - FixedRows].HasPickList then
begin
ARect.Left := ARect.Right - EditList.ButtonWidth;
Details := StyleServices.GetElementDetails(tgDropDownButtonNormal);
StyleServices.DrawElement(Canvas.Handle,Details,ARect);
end;
end;
procedure TValueListEditor.MouseDown(Button: TMouseButton; Shift: TShiftState;
X,Y: Integer);
var
ACol: Integer;
ARow: Integer;
begin
inherited MouseDown(Button,Shift,X,Y);
MouseToCell(X,Y,ARow);
if (Button = mbLeft) and (ARow > FixedRows) and
ItemProps[ARow - FixedRows].HasPickList and
not EditList.ListVisible and MouSEOverButton(X) then
begin
EditorMode := True;
TInplaceEditListAccess(EditList).DropDown;
end;
end;
function TValueListEditor.MouSEOverButton(X: Integer): Boolean;
begin
Result := (UseRightToLeftAlignment and (X < EditList.ButtonWidth)) or
(not UseRightToLeftAlignment and (X > ClientWidth - EditList.ButtonWidth));
end;