How To Make Simple Open Dialog with Borland Delphi 7

The TOpenDialog is a visual component. It is used to allow a user to select one or more files to open.

It can be defined by dragging the open dialog icon from the Dialogs tab in Delphi, or by defining a TOpenDialog variable.

Creating the dialog object:


var
 openDialog : TOpenDialog;
begin
 openDialog := TOpenDialog.Create(self);

Note that the dialog must have an anchor – here we provide the current object – self – as the anchor.

Setting Filter:

[/sociallocker]


//For one extension files
openDialog.Filter := 'Text files only|*.txt';
//For two or more extension files
openDialog.Filter := 'Text and Word files only|*.txt;*.doc';

Here’s the full source code:


//******************************************//
// Sampel Source Code Learning Delphi //
// OpenDialog //
// 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;
 dlgOpen1: TOpenDialog;
 lbl1: TLabel;
 mmo1: TMemo;
 procedure btn1Click(Sender: TObject);
 procedure FormCreate(Sender: TObject);
 private
 { Private declarations }
 public
 { Public declarations }
 end;

var
 Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
var
 openDialog : TOpenDialog; // Open dialog variable
begin
 // Create the open dialog object - assign to our open dialog variable
 openDialog := TOpenDialog.Create(self);

 // Set up the starting directory to be the current one
 openDialog.InitialDir := GetCurrentDir;

 // Only allow existing files to be selected
 openDialog.Options := [ofFileMustExist];

 // Allow only .txt to be selected
 openDialog.Filter :=
 'Text files|*.txt';

 // Select pascal files as the starting filter type
 openDialog.FilterIndex := 1;

 // Display the open file dialog
 if openDialog.Execute
 then
 begin
 lbl1.Caption := openDialog.FileName;
 mmo1.Lines.LoadFromFile(openDialog.FileName);
 end
 else ShowMessage('Open file was cancelled');

 // Free up the dialog
 openDialog.Free;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
 Caption := 'Open Dialog [Simple Sample]';
 mmo1.Clear;
 lbl1.Caption := '';
end;
end.