object Form1: TForm1
Left = 278
Top = 133
Width = 1057
Height = 540
Caption = 'Form1'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
OldCreateOrder = False
PixelsPerInch = 96
TextHeight = 13
object wwDBGrid1: TwwDBGrid
Left = 48
Top = 64
Width = 593
Height = 433
ControlType.Strings = (
'OrderID;CustomEdit;wwExpandButton1;T')
Selected.Strings = (
'ID'#9'20'#9'ID'
'OrderID'#9'20'#9'OrderID'#9'F')
IniAttributes.Delimiter = ';;'
TitleColor = clBtnFace
FixedCols = 0
ShowHorzScrollBar = True
DataSource = DataSource2
TabOrder = 0
TitleAlignment = taLeftJustify
TitleFont.Charset = DEFAULT_CHARSET
TitleFont.Color = clWindowText
TitleFont.Height = -11
TitleFont.Name = 'MS Sans Serif'
TitleFont.Style = []
TitleLines = 1
TitleButtons = False
end
object wwExpandButton1: TwwExpandButton
Left = 304
Top = 96
Width = 124
Height = 16
Grid = wwDataInspector1
AutoHideExpand = True
Caption = 'wwExpandButton1'
DataField = 'OrderID'
DataSource = DataSource2
TabOrder = 1
end
object wwDataInspector1: TwwDataInspector
Left = 256
Top = 144
Width = 320
Height = 120
ScrollBars = ssBoth
TabOrder = 2
DataSource = DataSource1
Items = <
item
DataSource = DataSource1
DataField = 'ID'
Caption = 'ID'
ReadOnly = True
WordWrap = False
end
item
DataSource = DataSource1
DataField = 'Naam'
Caption = 'Naam'
WordWrap = False
end
item
DataSource = DataSource1
DataField = 'Bla'
Caption = 'Bla'
WordWrap = False
end>
CaptionWidth = 100
Options = [ovColumnResize, ovRowResize, ovEnterToTab, ovHighlightActiveRow, ovCenterCaptionVert]
CaptionFont.Charset = DEFAULT_CHARSET
CaptionFont.Color = clWindowText
CaptionFont.Height = -11
CaptionFont.Name = 'MS Sans Serif'
CaptionFont.Style = []
Visible = False
end
object ADOConnection1: TADOConnection
Connected = True
ConnectionString =
'Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initi' +
'al Catalog=Test;Data Source=LOMPERTJE;Use Procedure for Prepare=' +
'1;Auto Translate=True;Packet Size=4096;Workstation ID=LOMPERTJE'
LoginPrompt = False
Provider = 'SQLOLEDB.1'
Left = 144
Top = 336
end
object ADOQuery1: TADOQuery
Active = True
Connection = ADOConnection1
CursorType = ctStatic
Parameters = <>
SQL.Strings = (
'select * from Orders,dossiers'
'where orders.id = dossiers.orderid')
Left = 272
Top = 384
object ADOQuery1ID: TAutoIncField
FieldName = 'ID'
ReadOnly = True
end
object ADOQuery1Naam: TStringField
FieldName = 'Naam'
FixedChar = True
Size = 10
end
object ADOQuery1Bla: TStringField
FieldName = 'Bla'
FixedChar = True
Size = 10
end
end
object DataSource1: TDataSource
DataSet = ADOQuery1
Left = 272
Top = 432
end
object DataSource2: TDataSource
DataSet = ADOQuery2
Left = 368
Top = 432
end
object ADOQuery2: TADOQuery
Active = True
Connection = ADOConnection1
CursorType = ctStatic
DataSource = DataSource1
Parameters = <>
SQL.Strings = (
'select * from Dossiers'
'where orderid = id')
Left = 368
Top = 384
end
end
20 Jan
Master-Detail (Expand/Collapse) in TwwDBGrid
17 Jun
Mimize to System Tray
If you want to avoid your exe displayed in the Taskbar and want to display the same into the System Tray then here is the code you are looking for….
First you need to creat the NotifyIcon like below
procedure TfrmWSCMIMICSNotify.CreateTrayIcon;
begin
IconData.cbSize := sizeof(IconData); // Should be Declared as IconData: TNotifyIconData;
IconData.Wnd := Handle; // Handle to our Form
IconData.uID := 100;
IconData.uFlags := NIF_MESSAGE + NIF_ICON + NIF_TIP;
IconData.uCallbackMessage := WM_USER + 1; // Our Callback ID
IconData.hIcon := Application.Icon.Handle; // Use our application Icon
StrPCopy(IconData.szTip, Application.Title);
end;
Then use this procedure
procedure TfrmWSCMIMICSNotify.MinimizeToTray;
begin
Shell_NotifyIcon(NIM_ADD, @IconData); // Add Tray Icon here
Self.Hide; // Hide our Form…
ShowWindow(Application.Handle, SW_HIDE); // …and hide application from TaskBar.
end;
procedure TfrmWSCMIMICSNotify.MinimizeToTray;
begin
Shell_NotifyIcon(NIM_ADD, @IconData); // Add Tray Icon here
Self.Hide; // Hide our Form…
ShowWindow(Application.Handle, SW_HIDE); // …and hide application from TaskBar.
end;
5 Jun
Adding Checkboxes To TStringGrid
The best way is to add a check box in a grid is using the “Objects” property of TStringGrid, Instead you can also find the code to draw checkbox inside the grid in most of the websites, but i feel this one is the best way than that, Let we see how to implement this.
To implement this here we we have two procedures which helps you to add a checkbox to the system. One of them help as to Add a checkbox to the TStringGrid and another will help us to align a checkbox in the grid. They are…..
SetCheckBoxAlignment
procedure TForm1.SetCheckBoxAlignment(iColNumber, iRowNumber:integer; bChecked :Boolean);
var
NewCheckBox :TCheckBox;
Rect :TRect;
TempInt :Integer;
begin
NewCheckBox := (StringGrid1.Objects[iColNumber, iRowNumber] as TCheckBox);
if NewCheckBox <> nil then
begin
Rect := StringGrid1.CellRect(iColNumber,iRowNumber);
TempInt := TRUNC((Rect.Right – Rect.Left)/2);
NewCheckBox.Left := StringGrid1.Left + Rect.Left + TempInt;
NewCheckBox.Top := StringGrid1.Top + Rect.Top+2;
NewCheckBox.Width := TempInt;
NewCheckBox.Height := Rect.Bottom – Rect.Top;
NewCheckBox.Visible := True;
if bChecked then
begin
NewCheckBox.Checked := True;
end else
begin
NewCheckBox.Checked := False;
NewCheckBox.Color := clBlue;
end;
end;
end;
AddCheckBox
procedure TForm1.AddCheckBox(iColNumber: integer; iRowNumber: Integer);
var
NewCheckBox :TCheckBox;
begin
NewCheckBox := TCheckBox.Create(StringGrid1);
NewCheckBox.Visible := False;
NewCheckBox.Color := clWhite;
NewCheckBox.OnClick := CheckBox1.OnClick; //Place one check box on you form..
NewCheckBox.Parent := Panel1; // Place string grid on one panel
StringGrid1.Objects[iColNumber, iRowNumber] := NewCheckBox;
SetCheckBoxAlignment(iColNumber, iRowNumber, True); // Calling align function
end;
You can change modify the above to make it work for your project, Thanks.
5 Jun
Delphi – Single application instance
Limiting an application to start just once per machine is usually required when an external resource such as a Comport is accessed. This feature is achieved by allocation of a global variable, such as a mutex.
FINDWINDOW METHOD:
The easiest way to look for an already running instance of an application is to use the FindWindow API function. The FindWindow function retrieves the handle of the window provided with the class name and window caption. In Delphi, the name of the window (form) class is the name of the form’s class, for example ‘TForm1’. Here’s the code:
program Project1; uses Forms, Windows, Unit1 in 'Unit1.pas' {Form1}; {$R *.res} var PreviousHandle : THandle; begin PreviousHandle := FindWindow('TForm1','Form1'); if PreviousHandle = 0 then begin Application.Initialize; Application.CreateForm(TForm1, Form1); Application.Run; end else SetForegroundWindow(PreviousHandle); end.
In our sample application we have only one form: Form1. This form is the main form of the project. To find a copy of the application already running, we can call the FindWindow API function that retrieves the handle of an existing window (the main form of the application). If the function fails (window with a specified class name and caption canot be found) the function returns 0. If the function returns the non-zero handle value, meaning that the system has found a window with specified parameters, we use the SetForegroundWindow API call. This function, provided with the window handle, activates the window and brings it to the foreground – making it the active window. Since Form1 is the main window of the application – the (already running) application becomes active. However, if the window was minimized we’ll first need to restore it to its previous state and then bring it to “top”.
The code above might look ok, but is not what we want.
First, such a code would prevent you from running your application from the IDE (at design time) – since at design time the window with the specified class name and the caption already exists, it’s the design time window of your main form.
Second, this code is not so safe, since there may be many Delphi applications on the system running, that have a form whose class name is “TForm1” – how can you be sure that this particular form (window) found by the FindWindow function is in fact a form belonging to your application? You cannot.
To overcome this problem, we’ll turn to threading. In Windows, one common way of object synhronization is creating a mutex object (mutually exclusive). In general, mutexes are used to synchronize two (or more) different applications – in our case we’ll create a mutex to synchronize instances of the same application.
Mutex – could do
The following code attempts to create a named mutex. If the function (CreateMutex) fails, you can be sure that an instance of the application is already running.
program Project1; uses Forms, Windows, Unit1 in 'Unit1.pas' {Form1}; {$R *.res} var Mutex : THandle; begin Mutex := CreateMutex(nil, True, 'My_Unique_Application_Mutex_Name'); if (Mutex = 0) OR (GetLastError = ERROR_ALREADY_EXISTS) then begin // code to searh for, and activate // the previous (first) instance end else begin Application.Initialize; Application.CreateForm(TForm1, Form1); Application.Run; if Mutex <> 0 then CloseHandle(Mutex); end; end; end.
.
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