mask,edit,components,delphi

Ayaz 10/21/2016 0

This example uses three mask edit components on a form, where the third mask edit box is set to be read only. When the application runs, it initializes the mask edit boxes to contain the empty string, to use the Courier font, and to use a particular mask, corresponding to IP address coding conventions. The mask edit boxes display the IP address, the subnet mask, and the subnet address respectively. When the user exits the subnet mask edit box, the subnet address is automatically calculated using bitwise AND operations and displayed in the third mask edit box. An additional test is made to assure that the values in the IP address and in the subnet mask are in the interval from 0 through 255, as this validation test cannot be accomplished using the edit mask property alone.

Delphi
 procedure TForm1.FormCreate(Sender: TObject);
begin
  { Initialize the maskedit boxes to contain the empty string. }
  MaskEdit1.Text := '';
  MaskEdit2.Text := '';
  MaskEdit3.Text := '';
 
  { Use the Courier font in the maskedit boxes. }
  MaskEdit1.Font.Name := 'Courier';
  MaskEdit2.Font.Name := 'Courier';
  MaskEdit3.Font.Name := 'Courier';
 
  {
  Initialize the mask of each maskedit box
  according to IP address coding conventions.
  }
  MaskEdit1.EditMask := '!099.099.099.099;1; ';
  MaskEdit2.EditMask := '!099.099.099.099;1; ';
  MaskEdit3.EditMask := '!099.099.099.099;1; ';
 
  MaskEdit2.OnExit := MaskEdit2Exit;
end;
 
procedure TForm1.MaskEdit2Exit(Sender: TObject);
var
  net1, net2, host1, host2,
  netmask1, netmask2, hostmask1, hostmask2,
  sub_net1, sub_net2, sub_host1, sub_host2: Integer;
 
  IP, mask: String;
 
begin
  // Extract the net and host address from the IP.
  IP := MaskEdit1.Text;
  net1 := StrToInt(TrimRight(Copy(IP, 0, 3)));
  net2 := StrToInt(TrimRight(Copy(IP, 5, 3)));
  host1 := StrToInt(TrimRight(Copy(IP, 9, 3)));
  host2 := StrToInt(TrimRight(Copy(IP, 13, 3)));
 
  // A range test that you cannot validate through edit masks.
  if ((net1 < 0) Or (net1 > 255) Or
      (net2 < 0) Or (net2 > 255) Or
      (host1 < 0) Or (host1 > 255) Or
      (host2 < 0) Or (host2 > 255)) then
    raise EArgumentException.Create('Not a valid IP address.');
 
  // Extract the net and host mask from the subnet mask.
  mask := MaskEdit2.Text;
  netmask1 := StrToInt(TrimRight(Copy(mask, 0, 3)));
  netmask2 := StrToInt(TrimRight(Copy(mask, 5, 3)));
  hostmask1 := StrToInt(TrimRight(Copy(mask, 9, 3)));
  hostmask2 := StrToInt(TrimRight(Copy(mask, 13, 3)));
 
  // A range test that you cannot validate through edit masks.
  if ((netmask1 < 0) Or (netmask1 > 255) Or
      (netmask2 < 0) Or (netmask2 > 255) Or
      (hostmask1 < 0) Or (hostmask1 > 255) Or
      (hostmask2 < 0) Or (hostmask2 > 255)) then
    raise EArgumentException.Create('Not a valid subnet mask.');
 
  // Compute the subnet address using bitwise AND.
  sub_net1 := net1 And netmask1;
  sub_net2 := net2 And netmask2;
  sub_host1 := host1 And hostmask1;
  sub_host2 := host2 And hostmask2;
 
  // Display the subnet address.
  MaskEdit3.Text :=
    IntToStr(sub_net1)   '.'   IntToStr(sub_net2)   '.'  
    IntToStr(sub_host1)   '.'   IntToStr(sub_host2);
end; 

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