组件的克隆问题!

Question

//问题 下面是一个组件COPY 函数，在组件TLabel TButton TPanel TMemo.....等测试没有问题  但TRichEdit TForm即报错，错误见下
procedure TForm1.ComponentToStr(Sender: TComponent);
var
  MemStream: TMemoryStream;
  FileStream: TFileStream;
begin
    MemStream:= TMemoryStream.Create;
    try
        FileStream:= TFileStream.Create('C:\Tmp.txt',fmCreate); 
        try
            MemStream.WriteComponent(Sender);
            MemStream.Position:= 0;
            ObjectBinaryToText(MemStream,FileStream);
        finally
            FileStream.Free;
        end;
    finally
        MemStream.Free;
    end;
end;function TForm1.StrToComponent(Sender: TComponent): TComponent;
var
  MemStream: TMemoryStream;
  FileStream: TFileStream;
begin
    FileStream:= TFileStream.Create('C:\Tmp.TXT',fmOpenReadWrite);
    try
        FileStream.Position:=0;
        MemStream:= TMemoryStream.Create;
        try
            ObjectTextToBinary(FileStream,MemStream);
            MemStream.Position:=0;
            //Result:= TComponent(MemStream.ReadComponent(Sender)); //如果Sender为被COPY对象，则可以通过，只是原来的会丢失
              Result:= TComponent(MemStream.ReadComponent(nil)); //此处报错
              //Error  Raised exception class einvalidoperation with message 'control' has no paren 
              //MemStream.ReadComponent(Result);
        finally
            MemStream.Free;
        end;
    finally
        FileStream.Free;
    end;
end;

Answer 1

procedure TForm1.ComponentToStr(Sender: TComponent);
var
  MemStream: TMemoryStream;
  FileStream: TFileStream;
begin
        FileStream:= TFileStream.Create('C:\Tmp.txt', fmCreate);
        try
            FileStream.WriteComponentRes('ComponentRes', Sender);
        finally
            FileStream.Free;
        end;
end;function TForm1.StrToComponent(Sender: TComponent): TComponent;
var
  FileStream: TFileStream;
begin
    FileStream:= TFileStream.Create('C:\Tmp.TXT',fmOpenReadWrite);
    try
        Result:= FileStream.ReadComponentRes(Sender); 
    finally
        FileStream.Free;
    end; 
end;克隆复杂对象（对象内属性也是对象）
要用TFileStream.WriteComponentRes和TFileStream.ReadComponentRes(Sender);
进行深度克隆

Answer 2

nil,不报错,才怪呢,读得源地方都没得,怎么读咯.

Answer 3

用的meiqingsong方法 还有TRichEdit的类你有没有注册

Answer 4

//这个问题应该叫组件的序列化吧！unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}//添加一个 Memo1 然后修改其内容
procedure TForm1.Button1Click(Sender: TObject);
begin
  WriteComponentResFile('c:\temp\memo.dat', Memo1);
end;
//反序列化, 读回
procedure TForm1.Button2Click(Sender: TObject);
begin
  ReadComponentResFile('c:\temp\memo.dat', Memo1);
end;
//序列化
procedure TForm1.Button3Click(Sender: TObject);
var
  stream: TStream;
const
  strPath = 'c:\temp\m.dat';
begin
  stream := TFileStream.Create(strPath, fmCreate);
  stream.WriteComponentRes(Memo1.ClassName, Memo1);
  stream.Free;
end;
//反序列化
procedure TForm1.Button4Click(Sender: TObject);
var
  stream: TStream;
const
  strPath = 'c:\temp\m.dat';
begin
  stream := TFileStream.Create(strPath, fmOpenRead);
  stream.ReadComponentRes(Memo1);
  stream.Free;
end;end.