unit1.~pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Edit1: TEdit;
    Label1: TLabel;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Memo1MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure Memo1Change(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  FName:String;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject); //打开文件
begin
  FName:=Edit1.Text ;  //获取要打开的文件名
  Memo1.Lines.LoadFromFile(FName); //打开该文件
end;

procedure TForm1.Memo1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if Memo1.SelLength >0 then //如果有文本被选中
    begin
      button3.Enabled :=true;//剪切按钮可用
      button4.Enabled:=true;  //复制按钮可用
      button6.Enabled:=true;  //删除按钮可用
    end
    else
        begin
          button3.Enabled :=false; //剪切按钮不可用
          button4.Enabled:=false;  //复制按钮不可用
          button6.Enabled:=false;   //删除按钮不可用
        end
 end;

procedure TForm1.Memo1Change(Sender: TObject);//Memo组件的内容发生了改变
begin
  Button2.Enabled :=true; //保存按钮可用
end;

procedure TForm1.Button2Click(Sender: TObject);//保存按钮
begin
  Memo1.Lines.SaveToFile(FName);//保存文件
  Button2.Enabled :=False;//保存按钮不可用
end;

procedure TForm1.Button3Click(Sender: TObject);//剪切按钮
begin
  Memo1.CutToClipboard; //执行剪切操作
  Button5.Enabled :=True;//粘贴按钮可用
  button3.Enabled :=false;//剪切按钮不可用
  button4.Enabled:=false; //复制按钮不可用
end;

procedure TForm1.Button4Click(Sender: TObject);//复制按钮
begin
  Memo1.CopyToClipboard ; //执行复制操作
  Button5.Enabled :=True; //粘贴按钮可用
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
  Memo1.PasteFromClipboard ;//粘贴操作
  Button3.Enabled:=False;//剪切按钮不可用
  Button4.Enabled :=False; //复制按钮不可用
end;

procedure TForm1.Button6Click(Sender: TObject);  //删除按钮
begin
  Memo1.ClearSelection ; //删除选中的文本
end;

end.