delphi memo1 行倒序排列三种方法

来源：http://www.xuexidashi.vip

unit Unit1;

interface

uses

Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,

System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,

Vcl.StdCtrls;

type

TForm1 = class(TForm)

Memo1: TMemo;

Memo2: TMemo;

Button1: TButton;

Button2: TButton;

Button3: TButton;

Memo3: TMemo;

procedure Button1Click(Sender: TObject);

procedure Button2Click(Sender: TObject);

procedure Button3Click(Sender: TObject);

procedure FormCreate(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);

var

I: Integer;

T1, T2: Integer;

begin

if Memo1.Text <> '' then

begin

T1 := GetTickCount;

Memo2.Clear;

for I := Memo1.Lines.Count - 1 downto 0 do

Memo2.Lines.Add(Memo1.Lines[I]);

T2 := GetTickCount;

Memo3.Lines.Add('第一种用时：' + IntToStr(T2 - T1));

end;

procedure TForm1.Button2Click(Sender: TObject);

var

I: Integer;

T1, T2: Integer;

begin

if Memo1.Text <> '' then

begin

T1 := GetTickCount;

Memo2.Lines.BeginUpdate;

Memo2.Clear;

for I := Memo1.Lines.Count - 1 downto 0 do

Memo2.Lines.Add(Memo1.Lines[I]);

Memo2.Lines.EndUpdate;

T2 := GetTickCount;

Memo3.Lines.Add('第二种用时：' + IntToStr(T2 - T1));

end;

procedure TForm1.Button3Click(Sender: TObject);

var

I: Integer;

T1, T2: Integer;

SList: TStringList;

begin

if Memo1.Text <> '' then

begin

T1 := GetTickCount;

SList := TStringList.Create;

try

for I := Memo1.Lines.Count - 1 downto 0 do

SList.Add(Memo1.Lines[I]);

Memo2.Lines.BeginUpdate;

Memo2.Clear;

Memo2.Lines.Text := SList.Text;

Memo2.Lines.EndUpdate;

finally

SList.Free;

end;

T2 := GetTickCount;

Memo3.Lines.Add('第三种用时：' + IntToStr(T2 - T1));

end;

procedure TForm1.FormCreate(Sender: TObject);

begin

Memo3.Clear;

Memo3.Lines.Add('共有行数：' + IntToStr(Memo1.Lines.Count));

end;

end.

推荐分享