How to hide contents of TEdit and copy to Clip board? - delphi

Question

I am having one Delphi XE2 Project with 2 BitBtns and 2 TEdits. Both of the TEdits contain secret data, so I have hidden the contents. My requirement is copy the contents of TEdit1 to clipboard after BitBtn1 Click and similarly for TEdit2. Here is my sample code:
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons, Clipbrd;
type
TMainForm = class(TForm)
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Label5: TLabel;
Label6: TLabel;
Label7: TLabel;
Label8: TLabel;
Label9: TLabel;
Label10: TLabel;
Edit1: TEdit;
Edit2: TEdit;
Edit3: TEdit;
Edit4: TEdit;
Edit5: TEdit;
BitBtn1: TBitBtn;
BitBtn2: TBitBtn;
BitBtn3: TBitBtn;
BitBtn4: TBitBtn;
BitBtn5: TBitBtn;
procedure BitBtn1Click(Sender: TObject);
procedure BitBtn2Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
MainForm: TMainForm;
implementation
{$R *.dfm}
procedure TMainForm.BitBtn1Click(Sender: TObject);
begin
Edit1.PasswordChar := #0;
Clipboard.Clear;
Edit1.CopyToClipboard;
Edit1.PasswordChar := '*';
end;
procedure TMainForm.BitBtn2Click(Sender: TObject);
begin
Edit2.PasswordChar := #0;
Clipboard.Clear;
Edit2.CopyToClipboard;
Edit2.PasswordChar := '*';
end;
procedure TMainForm.FormCreate(Sender: TObject);
begin
Edit1.Text := 'User Name';
Edit1.PasswordChar := '*';
Edit2.Text := 'Password';
Edit2.PasswordChar := '*';
end;
end.
But the problem is as follows:
1. If the PasswordChar := '*'; is set, the contents can not be copied to clipboard.
2. If I compile my sample code, TEdit1 Contents is copied to Clipboard after clicking BitBtn1 but TEdit2 Contents is not copied to Clipboard after clicking BitBtn2, though the first operation (Clipboard.Clear;) performs successfully.
3. If I double click on TEdit2 then click on BitBtn2 now TEdit2 Contents is copied to Clipboard.
I don't know why it is happening so?

Answer 1

If you want to place text in the clipboard, do so like this:
Clipboard.AsText := SecretEdit.Text;
or
Clipboard.AsText := SecretEdit.SelText;
The reason that the default behaviour of the control is to block copying to the clipboard is in case you walk away from your machine without realising that you left a password in plain text on your clipboard for a malicious attacker to steal. You should consider whether or not you want to take that risk with your application's users.

Answer 2

If no text is selected, CopyToClipboard does nothing.
Use this :
procedure TMainForm.BitBtn2Click(Sender: TObject);
begin
Edit2.SetFocus;
Edit2.PasswordChar := #0;
Clipboard.Clear;
Edit2.CopyToClipboard;
Edit2.PasswordChar := '*';
end;
procedure TMainForm.BitBtn1Click(Sender: TObject);
begin
Edit1.SetFocus;
Edit1.PasswordChar := #0;
Clipboard.Clear;
Edit1.CopyToClipboard;
Edit1.PasswordChar := '*';
end;