TFileStream and Tmemorystream read, create, and merge files separately

function TFORM1.TEST;VARFS:TFILESTREAM;FS2:TFILESTREAM;FS3:TFILESTREAM;STR:STRING;MS:TMEMORYSTREAM;MS2:    Tmemorystream;sr:tstream;begin//tfilestream Create a text file str:= ' file operation ';    Fs:=tfilestream.create (' C:\1.txt ', fmcreate); Fs.    WriteBuffer ((PChar (str)) ^,length (str)); Fs.        Free;    TFileStream Read text file fs:=tfilestream.create (' C:\1.txt ', fmopenread);    SetLength (str,fs.size); Fs. Readbuffer ((PChar (str)) ^,fs.    Size);    ShowMessage (str); Fs.    Free;    TFileStream read text file ms:=tmemorystream.create; Ms.    LoadFromFile (' C:\1.txt ');    SetLength (str,ms.size); Ms.    Readbuffer ((PChar (str)) ^,ms.size); Ms.    Free;    ShowMessage (str);    Tmemorystream Create text file str:= ' file operation ';    Ms:=tmemorystream.create; Ms.    WriteBuffer ((PChar (str)) ^,length (str)); Ms.    SaveToFile (' C:\2.txt '); Ms.    Free;    Tmemorystream file merging ms:=tmemorystream.create; Ms.    LoadFromFile (' C:\1.txt '); Ms. Position:=ms.    size;//move file pointer ms2:=tmemorystream.create; MS2.    LoadFromFile (' C:\2.txt '); Ms. CopyFrom (ms2,0); Ms.    SaveToFile (' C:\3.txt '); Ms.    Free; MS2. Free;end;

TFileStream and Tmemorystream read, create, and merge files separately