procedure TMainForm.AclonRectSelectoolExecute(Sender;Tobject);
begin
MapDetail.CurrentTool := miRectSelectTool;
sb.Panele[2].Text := TAction(Sender).Hint;
end
简单地说明状态回放的一些功能所示：
type
ThistoryList = class(TList)
FHistoryinteger; //过去时的索引
procedure SetHistoryIndex(const Value: Integer): //过去时索引设置
protected
public
//通过SetHistoryIndex方法设置过去时的索引属性
property HistoryIndex:Integer read FHistoryIndex write
SethistoryIndex;
function Add(Item: pointer): Integer; //增加过时的索引
procegure Clear; override; //清空过去时的索引
procedure Delete(Index: Integer); //删除过去的索引
procedure Insert(Index: Integer; Item: Pointer); //插入过去的索引
function Goback: integer;
function GoForward: integer; //实现状态后退
function GoForward: integer //实现状态前朝
constructor Create ; //分类的构造
end
