Window Message und PowerBuilder

1
Window Message und PowerBuilder

• Ludwin Feiten
• Power People

2
Fahrplan

• Motivation
• Send Function
• Beispiel
• Suchen in der Win-API Help
• Beispiel für PB Custom Events

3
Motivation

• PowerBuilder hat die Send()-Funktion
• Die Informationen darüber sind verstreut und
  mühsam zu finden.

4
Window Events

• PowerBuilder ist eine Windows Anwendung
• Windows hat ein Event gesteuertes User Interface,
  das von PowerBuilder genutzt werden kann.
• Triggern von Events durch senden von Messages an
  Controls.
• SendMessage(HWND hWnd, UINT Msg, WPARAM wParam,
  LPARAM lParam )

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SendMessage Function

• In Windows sind nicht nur Windows windows
  sondern auch fast alle anderen visuellen Control
  wie Buttons, Scrollbars, Editfields, etc.
• Zur Identifizierung gibt es einen
• handle

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Send Function in PowerBuilder

• Send ( handle, message, lowword, long )
• handle A long whose value is the system handle
  of a window (that you have created in
  PowerBuilder or another application) to which you
  want to send a message.
• message An UnsignedInteger whose value is the
  system message number of the message you want to
  send.
• Lowword A long whose value is the integer value
  of the message. If this argument is not used by
  the message, enter 0.
• Long The long value of the message or a string.

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Send Function Beispiele

• Dieses Statement scrollt das Fenster w_emp eine
  Seite hoch
• Send(Handle(w_emp), 277, 2, 0)
• Das folgende Statements click den CommandButton
  cb_OK
• Send(Handle(Parent), 273, 0, Handle(cb_OK))

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Messages Wie kann man sie finden?

• windows API help
• http//msdn.microsoft. com/library/
• winuser.h
• C\Program Files\Sybase\Shared\PowerBuilder\cgen\h
  \nt\winuser.h

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Bspl. Tab out a field

• Suchen in der Windows API Hilfe mit
• Key pressed notification
• Führt zu
• WM_KEYDONW

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Syntax WM_KEYDOWN

• WM_KEYDOWN
• WPARAM wParam LPARAM lParam
• wParam Specifies the virtual-key code of the
  nonsystem key.
• lParam Specifies the repeat count, scan code,
  extended-key flag, context code, previous
  key-state flag, and transition-state flag, as
  shown in the following table.
• 0-15 Specifies the repeat count for the current
  message. The value is the number of times the
  keystroke is autorepeated as a result of the user
  holding down the key. If the keystroke is held
  long enough, multiple messages are sent. However,
  the repeat count is not cumulative.
• 16-23 Specifies the scan code. The value depends
  on the OEM
• 24 Specifies whether the key is an extended key,
  such as the right-hand ALT and CTRL keys that
  appear on an enhanced 101- or 102-key keyboard.
  The value is 1 if it is an extended key
  otherwise, it is 0,
• 25-28 Reserved do not use

• 29 Specifies the context code. The value is
  always 0 for a WM_KEYDOWN message
• 30 Specifies the previous key state. The value
  is 1 if the key is down before the message is
  sent, or it is zero if the key is up
• 31 Specifies the transition state. The value is
  always zero for a WM_KEYDOWN message
• Return Value An application should return zero
  if it processes this message.
• 24 Specifies whether the key is an extended key,
  such as the right-hand ALT and CTRL keys that
  appear on an enhanced 101- or 102-key keyboard.
  The value is 1 if it is an extended key
  otherwise, it is 0,
• 25-28 Reserved do not use
• 29 Specifies the context code. The value is
  always 0 for a WM_KEYDOWN message
• 30 Specifies the previous key state. The value
  is 1 if the key is down before the message is
  sent, or it is zero if the key is up
• 31 Specifies the transition state. The value is
  always zero for a WM_KEYDOWN message
• Return Value An application should return zero
  if it processes this message.

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Nächster Schritt

• winuser.h
• define WM_KEYDOWN 0x0100
• hex 0x0100 ist dec 256. (Windows Rechner in
  Wissenschaftlicher Ansicht)
• wParam muss der ASCII-Code for the Tab-Key sein
• Das ist 9.
• lParam ist Null.
• Der Aufruf ist send(Handle(this), 256,9,
  long(0,0))

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Besp. Scroll a window

• Win32 and COM Development gt  User Interface gt 
  Windows Shell gt  Windows Controls gt  Individual
  Control Information gt  Scroll Bars 

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Syntax WM_VSCROLL

• SB_THUMBPOSITION The user has dragged the scroll
  box (thumb) and released the mouse button. The
  high-order word indicates the position of the
  scroll box at the end of the drag operation.
• SB_THUMBTRACK The user is dragging the scroll
  box. This message is sent repeatedly until the
  user releases the mouse button. The high-order
  word indicates the position that the scroll box
  has been dragged to.
• SB_TOP Scrolls to the upper left.
• lParam
• If the message is sent by a scroll bar, this
  parameter is the handle to the scroll bar
  control. If the message is not sent by a scroll
  bar, this parameter is NULL.

• WM_VSCROLL
• WPARAM wParam
• LPARAM lParam
• wParam
• The high-order word specifies the current
  position of the scroll box if the low-order word
  is SB_THUMBPOSITION or SB_THUMBTRACK otherwise,
  this word is not used.
• The low-order word specifies a scroll bar value
  that indicates the user's scrolling request. This
  parameter can be one of the following values.
• SB_BOTTOM Scrolls to the lower right.
• SB_ENDSCROLL Ends scroll.
• SB_LINEDOWN Scrolls one line down.
• SB_LINEUP Scrolls one line up.
• SB_PAGEDOWN Scrolls one page down.
• SB_PAGEUP Scrolls one page up.

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Nächster Schritt

• winuser.h
• define WM_VSCROLL 0x0115
• hex 0x0115 ist dec 277.
• SB_PAGEDOWN ist 3
• lParam ist Null.
• Der Aufruf ist send(Handle(this), 277,3,
  long(0,0))

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Strategien zur Suche

• Suche in MSDN Home gt  MSDN Library gt  Win32 and
  COM Development gt  User Interface gt  Windows
  Shell gt  Windows Controls
• Subtopics
• General Control Information
• Individual Control Information
• Suche unter
• "Messages" and "Notifications"

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Strategien zur Suche

• Suche in winusers.h
• nach brauchbaren Schlagwörtern.
• Mappen von PB-Events auf WN-Events
• Suche in spezieller Liste-gt www.powerpeople.de

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PowerBuilder custom events

• pbm_custom01 event ID maps to wm_user0
• pbm_custom02 event ID maps to wm_user1,
• pbm_custom75 event ID to wm_user74.
• WM_USER is defined in winusers.h
• define WM_USER 0x0400 1024

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Application Ping-Pong
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Ping - Pong

• Suche der Instanzen des Programms (Find
  Instances)
• Schicken eines Pings (Send Ping)
• Empfangen des Ping (ue_ping)-gt Pong
• Empfangen des Pong (ue_pong)

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Find Instances

• If nRet gt 0 Then
• //
• // Clean up return string, preparing
  for
• // case-insensitive comparison.
• //
• TitleTmp upper(Left(TitleTmp,
  nRet))
• //
• // Use appropriate method to
  determine if
• // current window//s caption either
  starts
• // with or contains passed string.
• //
• CHOOSE Case Method
• Case FWP_STARTSWITH
• If pos(TitleTmp,
  upper(TitleStart)) 1 Then
• FindWindowPartial hWndTmp
• mle_windows.text TitleTmp ' HWND '
  string(FindWindowPartial) 'rn'
• //Exit
• End If
• Case FWP_CONTAINS

• // Original autor Karl E. Peterson
• // Aus VB "geklaut"
• ulong hWndTmp,
• FindWindowPartial
• string lpClassName,
• lpWindowName,
• TitleTmp,
• TitleStart
• integer nRet
• integer method
• constant integer FWP_STARTSWITH 1
• constant integer FWP_CONTAINS 0
• constant integer GW_HWNDNEXT 2
• TitleStart parent.title// "Application Ping
  Pong"
• mle_windows.text ""

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Send ping

• unsignedlong hndl_me,
• hndl_you
• hndl_me handle(parent)
• hndl_you long(em_win_handle.text)
• IF hndl_you gt 0 THEN
• // Send a ping to pbm_custom01 and transmit my
  handle and instance number in the params
• send (hndl_du, 1024, hndl_ich, il_nummer )
• ELSE
• MessageBox("Oups", em_window.text " is not
  running!")
• END IF

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ue_ping

• event ue_ping pbm_custom01
• Messagebox("Here is window "string(handle(this))
  ," Got a Ping from " string (wparam) " with
  Instance No. "string(lparam) )
• // Pong to sender of the Ping (Event Id1025)
• send (wparam, 1025, handle(this), il_number )
• end event

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ue_pong

• event ue_ping pbm_custom02
• Messagebox("Here is window "string(handle(this))
  ," Got the Pong from " string (wparam) "
  with Instance No. "string(lparam) )
• end event

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Starting Syscommands

• Start Screensaver
• To start the screen saver write
• /
• WM_SYSCOMMAND 0x0112 274
• SC_SCREENSAVE 0xF140 61760
• /
• send(handle(This),274,61760,0)

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Starting Syscommands

• Maximize a frame
• To maximize a window when it opens put the
  following code into the Open event.
• CONSTANT Integer WM_SYSCOMMAND 274
• CONSTANT UInt SC_MAXIMIZE 61488
• //
• Send(Handle(This), WM_SYSCOMMAND, SC_MAXIMIZE, 0)

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Starting Syscommands

• CONSTANT Integer WM_SYSCOMMAND 274
• CONSTANT UInt SC_MAXIMIZE 61488
• CONSTANT UInt SC_CLOSE 61536 //
  0xF060
• CONSTANT UInt SC_SCREENSAVE 61760 // 0xF140
• CONSTANT UInt SC_RESTORE 61728 //
  0xF120
• CONSTANT UInt SC_MINIMIZE 61472 // 0xF020
• Send(Handle(w_test), WM_SYSCOMMAND, SC_MINIMIZE,
  long(0,0) )
• send(Handle(Parent),16,0,0) //Close

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Ein Window ohne Titlebar verschieben

• Um ein Window ohne Titlebar zu verschieben muss
  der folgende Code in das mousedown event.
• CONSTANT uint WM_NCLBUTTONDOWN 161
• CONSTANT uint HTCAPTION 2
• Post( Handle( this ), WM_NCLBUTTONDOWN,
  HTCAPTION, Long( xpos, ypos ) )

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Einige Events
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Kontakt

• Sind noch Fragen offen?
• Bei Rückfragen oder Anregungen bitte an
• Ludwin Feiten
• Power People
• Inh. Ludwin Feiten
• Am Borsigturm 50
• D-13507 Berlin
• fon 49 (0)30 43032350
• fax [phone]
• http//www.powerpeople.de
• mailtoludwin.feiten_at_powerpeople.de