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)

private

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 FHistoryIndexwrite 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