Changing properties on a component is in my Delphi vocabulary. I created a button by writing code and it appears on the Form as its Parent, but I do not know how to execute anything with it.
Sample - create runtime TButton and set him event OnClick...
unit Unit1;
interface
uses Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls;
type
{ TForm1 }
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
private
FButton : TButton;
procedure OnButtonClickTest(Sender: TObject);
public
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
{ TForm1 }
procedure TForm1.FormCreate(Sender: TObject);
begin
FButton := TButton.Create(nil);
FButton.Parent := self;
FButton.Left := 10;
FButton.Top := 10;
FButton.Width := 75;
FButton.Height := 25;
FButton.Caption := 'Click';
FButton.OnClick := OnButtonClickTest;
end;
procedure TForm1.OnButtonClickTest(Sender: TObject);
begin
FButton.Caption := 'Test OK';
end;
end.
I create a dynamic button FButton. Place it on the main form (Parent: Self) and set the event handler to click on it (method: OnButtonClickTest). When you click on button, on her caption change text to "Test OK"
Related
I have created a simple Delphi form with a button that, when pressed, creates a label object in run time. I have created an on double click event for the label that shows a message to the screen. The problem is that after creating the label, I have to double click on the form before the double click event works on the label. Obviously this is not ideal as I would like to be able to double click on the label and trigger the event without having to first double click the form.
Here is the code for my form:
unit Unit4;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm4 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
procedure FormDblClick(Sender: TObject);
procedure MyLabelDblClick(Sender:TObject);
private
{ Private declarations }
LabelObject: TLabel;
public
{ Public declarations }
end;
var
Form4: TForm4;
implementation
{$R *.dfm}
procedure TForm4.Button1Click(Sender: TObject);
begin
LabelObject := TLabel.Create(Self);
LabelObject.Left := 100;
LabelObject.Top := 100;
LabelObject.Width := 200;
LabelObject.Height := 20;
LabelObject.Visible := True;
LabelObject.Parent := Self;
LabelObject.Caption := 'My Run Time Label';
LabelObject.Cursor := crHandPoint;
end;
procedure TForm4.FormDblClick(Sender: TObject);
begin
LabelObject.OnDblClick := MyLabelDblClick;
end;
procedure TForm4.MyLabelDblClick(Sender: TObject);
begin
showmessage('You double clicked My Run Time Label');
end;
end.
Thanks in advance for any help with this matter.
The problem is that after creating the label, I have to double click on the form before the double click event works on the label.
Assign LabelObject.OnDblClick when creating the label, i.e. inside the Button1Click event.
I am looking to create an effect similar to the lightbox effect seen on many website where the background of the screen fades out and the content you want to emphasize does not. What would be the best way to go about creating such an effect in delphi ?
The content I want to emphasize in this case is a movable panel located on my form and basically all I want to do is to fade out any area of the screen that is not directly under that panel.
Thanks.
Oscar
Create a new form and add this code to the FormCreate method. You could also change the properties using the properties inspector, but I'm choosing to show you the relevant properties using code:
unit Unit1;
// This is a full screen partially transparent black form.
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure FormClick(Sender: TObject);
end;
var
Form1: TForm1;
implementation
uses Unit2;
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
BorderStyle := bsNone;
Self.WindowState := wsMaximized;
AlphaBlend := true;
Alphablendvalue := 127;
Color := clBlack;
end;
procedure TForm1.FormShow(Sender: TObject);
begin
Form2.Show;
end;
procedure TForm1.FormClick(Sender: TObject);
begin
Close;
end;
end.
Here's a second form which has no border, which I am showing over top. It does not have alpha blending turned on, and the form style should be fsStayOnTop, or else you should use the ParentWindow property (on versions of Delphi that support that).
unit Unit2;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm2 = class(TForm)
Label1: TLabel;
procedure FormDeactivate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure FormActivate(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
FAutoDeactivate: Boolean;
FCounter: Integer;
procedure WMUser1(var Message:TMessage); message WM_USER+1;
public
property AutoDeactivate:Boolean read FAutoDeactivate write FAutoDeactivate;
end;
var
Form2: TForm2;
implementation
uses Unit1;
{$R *.dfm}
procedure TForm2.FormDeactivate(Sender: TObject);
begin
if Self.Visible and FAutoDeactivate then
begin
FAutoDeactivate := false;
Form1.Close;
end;
end;
procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Form1.Close;
end;
procedure TForm2.FormActivate(Sender: TObject);
begin
PostMessage(Self.Handle, WM_USER+1, 0, 0);
end;
procedure TForm2.WMUser1(var Message: TMessage);
begin
FAutoDeactivate := true;
end;
procedure TForm2.FormCreate(Sender: TObject);
begin
BorderStyle := bsNone;
Color := clWhite;
FormStyle := fsStayOnTop; // or set parent
end;
end.
That addresses how to make the whole screen "go dim", and then show something on top of that "dimmed area", but what you describe as "showing a panel in your main form" would require you to move that content out of your main form, or else clip a region out of form1, or use a combination of alpha blend plus transparency, but I don't have any code for those to show you.
If I was doing it, I would just float the thing I want not to be dimmed, above the full screen borderless 50% alpha form, as shown below.
But as you see, the screen isn't dimmed (screen brightness is not reduced), it's merely that we've done a 50% transparent layer of black which has blended in and darkened the overall screen appearance.
I have the same need as Oscar. After some search on the net, I found what is shown here.
It has helped me to do this, since it works. You can move what is emphasized in a Form instead of a Panel.
I use two forms. The first is use as "fader" and the second as dialogbox.
First
unit uFormFaded;
interface
uses
...
type
TFormFaded = class(TForm)
procedure FormCreate(Sender: TObject);
private
{ Déclarations privées }
public
{ Déclarations publiques }
end;
var
FormFaded: TFormFaded;
implementation
{$R *.dfm}
procedure TFormFaded.FormCreate(Sender: TObject);
begin
Align := alClient;
AlphaBlend := true;
AlphaBlendValue := 100;
BorderStyle := bsNone;
Color := clBlack;
Enabled := false;
FormStyle := fsStayOnTop;
end;
end.
Second
unit UFormDlgBox;
interface
uses
...
type
TFormDlgBox = class(TForm)
procedure FormShow(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Déclarations privées }
public
{ Déclarations publiques }
end;
var
FormDlgBox: TFormDlgBox;
implementation
{$R *.dfm}
uses uFormFaded;
procedure TFormDlgBox.FormClose(Sender: TObject; var Action: TCloseAction);
begin
FormFaded.Close;
end;
procedure TFormDlgBox.FormShow(Sender: TObject);
begin
FormFaded.Show;
end;
end.
The use
FormDlgBox.ShowModal;
I tried to reproduce this schema creating the forms in run-time an make the TFormDlgBox Owns and create the TFormFaded but it doesn't work. It seems it works only with forms created in design-time.
as an extension of my previous post forms an a pagecontrol at runtime
I need a solution how to pass a buttonclick event back to the parent pagecontrol.
Do I have a assign a click function as a property and assign a new click function to all my forms for all the buttons i have placed :-( .... much work , any better solution
MyMainForm = CLass( )
....
aPagecontrol : TPageControl;
aTabForm_1 : TTabForm_1 ; // in the real case I use an dynamic array
aTabForm_2 : TTabForm_2 ;
aTabForm_3 : TTabForm_3 ;
....
UserData : TUserdata ; // lot of user data ....
function MyMainForm.CreateTabAndForm: TTabForm_1;
var
tabSheet : TTabSheet;
begin
//Create a new tab sheet
tabSheet := TTabSheet.Create(PageControl1) ;
tabSheet.PageControl := PageControl1;
//create a form
Result := TTabForm_1.Create(tabSheet) ;
Result.Parent := tabSheet;
Result.Align := alClient;
Result.BorderStyle := bsNone;
Result.Visible := true;
tabSheet.Caption := Result.Caption;
//activate the sheet
PageControl1.ActiveSheet := tabSheet;
end;
// program code , now failing :
aTabForm_1 := CreateTabAndForm;
aTabForm_1.onclick := MyButtonOnclick; // here AV happens !!
....
end;
the definition of the form
//
TTabForm_1 = class(TForm)
...
property clickButton1 : TClickfunction .......
end;
Solution #1 -> pass all the data to TTabForm_1 using properties
Solution #2 -> pass Button Click event to Mainform
target : readable code - good design
One way to expose events raised inside a form or control is like this :
unit Unit2;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm2 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
FButton1Clicked : TNotifyEvent; //Create a private TNotifyEvent field
public
// ...and expose it as a property
property OnButton1Click : TNotifyEvent read FButton1Clicked
write FButton1Clicked;
end;
implementation
{$R *.dfm}
procedure TForm2.Button1Click(Sender: TObject);
begin
// Execute the method if it has been assigned when Button1 is clicked.
if Assigned(FButton1Clicked) then FButton1Clicked(Sender);
end;
end.
Which you would consume like :
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Unit2;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
private
FForm2 : TForm2;
procedure Form2ButtonClick(sender : TObject);//Create a TNotifyEvent handler
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
FForm2 := TForm2.Create(self);
//Assign a method to your custom event property
FForm2.OnButton1Click := Form2ButtonClick;
FForm2.Show;
end;
procedure TForm1.Form2ButtonClick(sender: TObject);
begin
// Do Something...
end;
end.
Of course, you don't have to use a TNotifyEvent, you can create any custom event, with parameters, that you like. For example
type
TFooEvent = procedure(ANumber : double; Sender : TObject) of object;
Which you could then use to send data with the click event :
if Assigned(FButton1Clicked) then FButton1Clicked(1.23, Button1);
I have two scenarios. One works, one does not. The first (the one that works) invloves a scrollbox sitting directly on a form that when a button is pushed it executes this code:
procedure TForm1.Button2Click(Sender: TObject);
begin
DrawPanel;
end;
procedure TForm1.DrawPanel;
begin
BuildPanel; //Resides on a seperate unit code pasted below
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
unit Unit3;
interface
uses ExtCtrls;
Var
TestPanel : Tpanel;
Procedure BuildPanel;
implementation
procedure BuildPanel;
begin
TestPanel := TPanel.Create(Nil);
end;
end.
The code is identical except for a small difference in the second scenario. The scrollbox sits on a frame that is added to the Templates palette and then dropped down on the form. The button click calls:
procedure TForm1.Button1Click(Sender: TObject);
begin
TestFrame.DrawPanel;
end;
procedure TTestFrame.DrawPanel;
begin
BuildPanel; //Still points to the unit3 code above
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
However the panel will not display in the scrollbox that sits on the frame, when triggered at runtime. I'm not really sure why, can anybody help out? I hope I was specific enough in my question, let me know if anything is unclear. Thanks in advance.
Here's all the code in order.....Hopefully it make it more clear:
//This is the form
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls, Unit2, Unit3;
type
TForm1 = class(TForm)
Button1: TButton;
TTestFrame1: TTestFrame;
ScrollBox1: TScrollBox;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
TestFrame: TTestFrame;
Procedure DrawPanel;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
begin
TestFrame.DrawPanel;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
DrawPanel;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
TestFrame.Free;
end;
procedure TForm1.FormShow(Sender: TObject);
begin
TestFrame := TTestFrame.Create(Form1);
end;
procedure TForm1.DrawPanel;
begin
BuildPanel;
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
end.
//This is the frame
unit Unit2;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Unit3;
type
TTestFrame = class(TFrame)
ScrollBox1: TScrollBox;
private
{ Private declarations }
public
{ Public declarations }
Procedure DrawPanel;
end;
implementation
{$R *.dfm}
{ TTestFrame }
procedure TTestFrame.DrawPanel;
begin
BuildPanel;
TestPanel.Height := 40;
TestPanel.Width := 100;
TestPanel.Left := Trunc(ScrollBox1.Width / 2) - Trunc(TestPanel.Width / 2);
TestPanel.Top := Trunc(ScrollBox1.Height / 2) - Trunc(TestPanel.Height / 2);
TestPanel.Visible := True;
TestPanel.Parent := ScrollBox1;
end;
end.
//This is the unit that mocks my data structure
//In reality it creates an Array of Tpanel that is part of a class.
unit Unit3;
interface
uses ExtCtrls;
Var
TestPanel : Tpanel;
Procedure BuildPanel;
implementation
procedure BuildPanel;
begin
TestPanel := TPanel.Create(Nil);
end;
end.
You just forgot to assign a parent to your dynamic created TestFrame.
I am looking to create an effect similar to the lightbox effect seen on many website where the background of the screen fades out and the content you want to emphasize does not. What would be the best way to go about creating such an effect in delphi ?
The content I want to emphasize in this case is a movable panel located on my form and basically all I want to do is to fade out any area of the screen that is not directly under that panel.
Thanks.
Oscar
Create a new form and add this code to the FormCreate method. You could also change the properties using the properties inspector, but I'm choosing to show you the relevant properties using code:
unit Unit1;
// This is a full screen partially transparent black form.
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure FormClick(Sender: TObject);
end;
var
Form1: TForm1;
implementation
uses Unit2;
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
BorderStyle := bsNone;
Self.WindowState := wsMaximized;
AlphaBlend := true;
Alphablendvalue := 127;
Color := clBlack;
end;
procedure TForm1.FormShow(Sender: TObject);
begin
Form2.Show;
end;
procedure TForm1.FormClick(Sender: TObject);
begin
Close;
end;
end.
Here's a second form which has no border, which I am showing over top. It does not have alpha blending turned on, and the form style should be fsStayOnTop, or else you should use the ParentWindow property (on versions of Delphi that support that).
unit Unit2;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm2 = class(TForm)
Label1: TLabel;
procedure FormDeactivate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure FormActivate(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
FAutoDeactivate: Boolean;
FCounter: Integer;
procedure WMUser1(var Message:TMessage); message WM_USER+1;
public
property AutoDeactivate:Boolean read FAutoDeactivate write FAutoDeactivate;
end;
var
Form2: TForm2;
implementation
uses Unit1;
{$R *.dfm}
procedure TForm2.FormDeactivate(Sender: TObject);
begin
if Self.Visible and FAutoDeactivate then
begin
FAutoDeactivate := false;
Form1.Close;
end;
end;
procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Form1.Close;
end;
procedure TForm2.FormActivate(Sender: TObject);
begin
PostMessage(Self.Handle, WM_USER+1, 0, 0);
end;
procedure TForm2.WMUser1(var Message: TMessage);
begin
FAutoDeactivate := true;
end;
procedure TForm2.FormCreate(Sender: TObject);
begin
BorderStyle := bsNone;
Color := clWhite;
FormStyle := fsStayOnTop; // or set parent
end;
end.
That addresses how to make the whole screen "go dim", and then show something on top of that "dimmed area", but what you describe as "showing a panel in your main form" would require you to move that content out of your main form, or else clip a region out of form1, or use a combination of alpha blend plus transparency, but I don't have any code for those to show you.
If I was doing it, I would just float the thing I want not to be dimmed, above the full screen borderless 50% alpha form, as shown below.
But as you see, the screen isn't dimmed (screen brightness is not reduced), it's merely that we've done a 50% transparent layer of black which has blended in and darkened the overall screen appearance.
I have the same need as Oscar. After some search on the net, I found what is shown here.
It has helped me to do this, since it works. You can move what is emphasized in a Form instead of a Panel.
I use two forms. The first is use as "fader" and the second as dialogbox.
First
unit uFormFaded;
interface
uses
...
type
TFormFaded = class(TForm)
procedure FormCreate(Sender: TObject);
private
{ Déclarations privées }
public
{ Déclarations publiques }
end;
var
FormFaded: TFormFaded;
implementation
{$R *.dfm}
procedure TFormFaded.FormCreate(Sender: TObject);
begin
Align := alClient;
AlphaBlend := true;
AlphaBlendValue := 100;
BorderStyle := bsNone;
Color := clBlack;
Enabled := false;
FormStyle := fsStayOnTop;
end;
end.
Second
unit UFormDlgBox;
interface
uses
...
type
TFormDlgBox = class(TForm)
procedure FormShow(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Déclarations privées }
public
{ Déclarations publiques }
end;
var
FormDlgBox: TFormDlgBox;
implementation
{$R *.dfm}
uses uFormFaded;
procedure TFormDlgBox.FormClose(Sender: TObject; var Action: TCloseAction);
begin
FormFaded.Close;
end;
procedure TFormDlgBox.FormShow(Sender: TObject);
begin
FormFaded.Show;
end;
end.
The use
FormDlgBox.ShowModal;
I tried to reproduce this schema creating the forms in run-time an make the TFormDlgBox Owns and create the TFormFaded but it doesn't work. It seems it works only with forms created in design-time.