How To Make Get Filesize with Non Format and Format with Borland Delphi 7

When working with files and folders from a Borland Delphi 7, application you sometimes need to know what is the size of a file (in bytes or non formating).

Get File Size

The FileSize function returns the size of a file in bytes, -1 if the file was not found.

The FileSize function as follows:


 //Returns file size in bytes or -1 if not found.
 function FileSize(fileName : wideString) : Int64;
 var
 sr : TSearchRec;
 begin
 if FindFirst(fileName, faAnyFile, sr ) = 0 then
 result := Int64(sr.FindData.nFileSizeHigh) shl Int64(32) + Int64(sr.FindData.nFileSizeLow)
 else
 result := -1;

 FindClose(sr) ;
 end;

When working with files from Borland Delphi 7 you might want to display the size of a file to the user in a Explorer-like format where the file size is not displayed in bytes – but the display depends on the size of the actual file.

To most users “21720″ is confusing – where “21.21 KB” is much more user friendly.

Format Byte Size to String

A custom Delphi function, FormatByteSize, converts a byte value into a string that represents the number expressed as a size value in bytes, kilobytes, megabytes, or gigabytes, depending on the size.

Format Byte Size to String function as follows:


//Format file byte size
 function FormatByteSize(const bytes: Longint): string;
 const
 B = 1; //byte
 KB = 1024 * B; //kilobyte
 MB = 1024 * KB; //megabyte
 GB = 1024 * MB; //gigabyte
 begin
 if bytes > GB then
 result := FormatFloat('#.## GB', bytes / GB)
 else
 if bytes > MB then
 result := FormatFloat('#.## MB', bytes / MB)
 else
 if bytes > KB then
 result := FormatFloat('#.## KB', bytes / KB)
 else
 result := FormatFloat('#.## bytes', bytes) ;
 end;

Command to run the functions above is:


procedure TForm1.btn1Click(Sender: TObject);
var
 fsize: Integer;
 fsext: String;
begin
 //Variable for filesize of filename
 fsize := FileSize('C:\test.txt');
 //Variable for filesize format
 fsext := FormatByteSize(fsize);

 //Show filesize of filename
 ShowMessage('File size (Non Format): ' + IntToStr(fsize));
 //Show filesize format
 ShowMessage('File size (With Format): ' + fsext);
end;

Once the application is started, it will appear as follows:

Result Get Filesize non Format

Result Get Filesize with Format from Get Filesize

If you want to use open dinamycs file, you can with Open Dialog.

Full Source Code:::


//******************************************//
// Sampel Source Code Learning Delphi //
// Get Filesize with Non Format and Format //
// by : G. Giarto //
// E-Mail : support@learning-delphi.com //
// Website: http://www.learning-delphi.com //
//******************************************//

unit Unit1;

interface

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

type
 TForm1 = class(TForm)
 btn1: TButton;
 lbl1: TLabel;
 lbl2: TLabel;
 lbl3: TLabel;
 btn2: TButton;
 procedure btn1Click(Sender: TObject);
 procedure FormCreate(Sender: TObject);
 procedure btn2Click(Sender: TObject);
 private
 { Private declarations }
 public
 { Public declarations }
 end;

var
 Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
 Caption := 'Get Filesize with Non Format and Format';
 lbl1.Caption := Caption;
 lbl2.Caption := 'Filename';
 lbl3.Caption := 'C:\test.txt';
 btn1.Caption := 'Get &Filesize';
 btn2.Caption := 'E&xit';
end;

 //Returns file size in bytes or -1 if not found.
 function FileSize(fileName : wideString) : Int64;
 var
 sr : TSearchRec;
 begin
 if FindFirst(fileName, faAnyFile, sr ) = 0 then
 result := Int64(sr.FindData.nFileSizeHigh) shl Int64(32) + Int64(sr.FindData.nFileSizeLow)
 else
 result := -1;

 FindClose(sr) ;
 end;

//Format file byte size
 function FormatByteSize(const bytes: Longint): string;
 const
 B = 1; //byte
 KB = 1024 * B; //kilobyte
 MB = 1024 * KB; //megabyte
 GB = 1024 * MB; //gigabyte
 begin
 if bytes > GB then
 result := FormatFloat('#.## GB', bytes / GB)
 else
 if bytes > MB then
 result := FormatFloat('#.## MB', bytes / MB)
 else
 if bytes > KB then
 result := FormatFloat('#.## KB', bytes / KB)
 else
 result := FormatFloat('#.## bytes', bytes) ;
 end;

procedure TForm1.btn1Click(Sender: TObject);
var
 fsize: Integer;
 fsext: String;
begin
 //Variable for filesize of filename
 fsize := FileSize('C:\test.txt');
 //Variable for filesize format
 fsext := FormatByteSize(fsize);

 //Show filesize of filename
 ShowMessage('File size (Non Format): ' + IntToStr(fsize));
 //Show filesize format
 ShowMessage('File size (With Format): ' + fsext);
end;

procedure TForm1.btn2Click(Sender: TObject);
begin
 Application.Terminate;
end;

end.