QTP - 17 Working with APIs 與windows API互動

17 Working with APIs

Concept: The MS API (Application Programming Interface)provides various functions to do operations like getting cursor coordinates,window handles, colors etc. But due to VBS limitations, only limited APIs canbe used in QTP.

Extern Object:

Syntax

Extern.Declare(RetType, MethodName, LibName, Alias [, ArgType(s)]) RetType: Data type of the value returned by the method. MethodName : Any valid procedure name. LibName : Name of the DLL or code resource (c:\mydll.dll)that contains the declared procedure. Alias : Name of the procedure in the DLL or code resource. Can be blank. ArgType: arguments that are passed to the procedure E.g. extern.Declare micLong,"GetForegroundWindow","user32.dll","GetForegroundWindow"

17.1 How can we get the topmost window?

Note：the topmost window 是QTP.

extern.Declare micLong,"GetForegroundWindow","user32.dll","GetForegroundWindow" 'Get the handle of the top most window hwnd = extern.GetForegroundWindow() hwndPro = "hwnd:= " & hwnd 'Check if a browser with that window handle exists isBrowser = Window(hwndPro).Exist(2) ‘Or isBrowser =  Browser(hwndPro).Exist(2)

17.2 How can we get the value of Windows Environment variables (not QTP Environmentvariables)?

'Declare the API GetEnvironmentVariable Extern.Declare micLong,"GetEnvironmentVariable","kernel32.dll","GetEnvironmentVariableA", _                                                             micString,micString+micByRef,micLong 'Get the environment variable "TEMP" value Extern.GetEnvironmentVariable "TEMP",s_EnvValue,255 'This will get the path for the temporary folder. print s_EnvValue         ‘C:\Users \AppData\Local\Temp

17.3 How can we check (select) an item from a List Box using a Windows API?

Extern.Declare micLong,"SendMessage","user32.dll","SendMessageA",micLong,micLong,micLong,micLong 'List Box message to set a selection Const LB_SETSEL = &H185 'Function to check the box at given index Function CheckListBox(hwnd, index)        extern.SendMessage hwnd, LB_SETSEL, True, index end function 'Function to uncheck the box at given index Function UnCheckListBox(hwnd, index)        extern.SendMessage hwnd, LB_SETSEL, False, index end function

17.4 How can we get the background color of a text box?

'Declare all the needed APIs Extern.Declare micLong,"GetPixel","gdi32","GetPixel",micLong,micLong,micLong Extern.Declare micLong,"GetWindowDC","user32","GetWindowDC",micLong Extern.Declare micLong,"ReleaseDC","user32","ReleaseDC",micLong,micLong Extern.Declare micLong,"GetDC","user32","GetDC",micLong Extern.Declare micLong,"SetForegroundWindow","user32","SetForegroundWindow",micLong Dim hDCSource Dim hWndSource Dim backColor 'Get the handle of the control hWndSource =Browser("b").Page("p"). WinEdit("Edit_4").GetROProperty("hwnd") 'Bring the window to foreground. This is important as GetPixel works only on visible pixels extern.SetForegroundWindow hWndSource 'Get the devic context handle hDCSource = Clng(Extern.GetDC(hWndSource)) 'Get the background color of pixel 1,1 relative to the control. backColor = Clng(Extern.GetPixel(hDCSource, Clng(1),Clng(1))) print backColor 'Release the device context handle Extern.ReleaseDC hWndSource, hDCSource

17.5 How can we simulate a keyboard event using a Windows API?

'Declare all the needed APIs Extern.Declare micVoid,"keybd_event","user32","keybd_event",micbyte,micbyte,micLong,micLong Extern.Declare micLong,"MapVirtualKey","user32","MapVirtualKeyA",micLong, micLong Const KEYEVENTF_EXTENDEDKEY = &H1 Const KEYEVENTF_KEYUP = &H2 Const KEYEVENTF_KEYDOWN = &H0 Sub KeyDown (keyAscii)    keyCode = extern.MapVirtualKey(keyAscii, 0)    extern.keybd_event keyAscii, keyCode, KEYEVENTF_KEYDOWN, 0 End Sub Sub KeyUp (keyAscii)    keyCode = extern.MapVirtualKey(keyAscii, 0)    extern.keybd_event keyAscii, keyCode, KEYEVENTF_KEYUP, 0 End Sub Sub KeyPress (keyAscii)                KeyDown keyAscii                KeyUp keyAscii End Sub Call KeyPress (49)             '1 key pressed Call KeyPress (13) 'enter key

Using the above code to simulate CTRL+ALT+S

‘Control =17; alt = 18; S=83 Call KeyDown(17) Call KeyDown(18) Call KeyDown(83 ) Call KeyUp(83 ) Call KeyUp(18) Call KeyUp(17)

17.6 How can we prevent a PC from being locked by its screen saver?

Extern.Declare imcVoid,"keybd_event","user32","keybd_event", micByte,micByte,micLong,micLong Extern.Declare imcVoid,"Sleep","kernel32","Sleep", micLong Const KEYEVENTF_KEYUP = &H2 While Ture                extern.keybd_event 0, 0, KEYEVENTF_KEYUP, 0                extern.Sleep 20000 Wend

Note: The above code may produce error because bin folder ofQTP should be added to windows PATH environment variable. Here is the code:

'Function to add a folder to PATH Public Function AddToSystemPath(ByVal Path)   Set objWMIService = GetObject("winmgmts:\\.\root\cimv2")   'Get the windows environment   Set colItems = objWMIService.ExecQuery _       ("Select * From Win32_Environment Where Name = 'Path'")   For Each objItem in colItems       'Add to PATH only if the path does not already exists       If InStr(objItem.VariableValue, Path)= 0 Then         'If path does not exist already then add it         strPath = objItem.VariableValue & ";" & Path         objItem.VariableValue = strPath         objItem.Put_       End If   Next End Function AddToSystemPath "C:\Program Files\Mercury Interactive\QuickTest Professional\bin"

17.7 How can we maximize a window or a browser?

Private Const SW_MAXIMIZE = 3 Extern.Declare micLong, "ShowWindow", "user32.dll", "ShowWindow", _               micHwnd, micLong 'In case we want to maximize a window then handle 'of that window needs to be used. hWndWindow = Browser("title:=about:blank").GetROProperty("hwnd") print  hWndWindow 'Maximize the window Extern.ShowWindow hWndWindow, SW_MAXIMIZE

17.8 How can we download a file form a URL to disk?

Extern.Declare micLong, "URLDownloadToFile", "urlmon", "URLDownloadToFileA", micLong, micString, micString, micLong, micLong sSourceURL = "http://www.baidu.com/img/baidu_sylogo1.gif" sTargetFile = "C:\logon.gif" extern.URLDownloadToFile 0, sSourceURL, sTargetFile, 0, 0

Using VB DLL in QTP:

Since VBS only support variant data type, not use structure.So API use COM object in VB.

'Steps to use API COM object in vb '1. registed DLL on PC: regsvr32 "C:\my.dll" '2. Access DLL in QTP Set winAPI = CreateObject("WindowsAPI.API")        ‘<ProjectName>.<ClassName> winAPI.Method1(args)

Running API Using Excel

Using Excel COM APIS to create a custom COM library: usingMacro.

‘Steps to create Macros in excel 1.      Press ALT+F11 to VB Editor 2.      Record/Script VB Macro 3.      Call the Macro in QTP using VBS

總而言之： 就是調人家excel寫好了的宏，就不用自己寫宏已經實作的功能。

Dynamicallygenerating an Excel Macro

This generates the needed macro at the run-time using VBEacutomation Classes.

‘Method 1:  importMacro at run-time

‘Smaple Code: Set xlsVBComponents = xlsWorkbook.VBProject.VBComponents 'Import the code xlsVBComponents.Import "C:\MyCode.Bas" xlsApp.Run "MacroFunction", argments

Note: it wills error (“Trust access to Visual Basicproject”), set Excel “ToolsàMacroàSecurity…àTrusted Publishers (Tab)à Check the check box (Trustaccess to VB project)”; or using following code set security status:

Set oShell = CreateObject("WScript.Shell") 'Enable Trust Access oShell.RegWrite "HKLM\SOFTWARE\Microsoft\Office\11.0\Excel\Security\AccessVBOM", 1, "REG_DWORD" 'Disable Trust Access oShell.RegDelete  "HKLM\SOFTWARE\Microsoft\Office\11.0\Excel\Security\AccessVBOM"

‘Method 2:

'Create the module file Const vbext_ct_StdModule = 1 Set oModule = xlWorkbook.VBProject.VBComponents.Add (vbext_ct_StdModule) oModule.Name = "MyCode" 'Add code using file oModule.CodeModule.AddFromFile "C:\MyCode.Bas"

‘Method 3: Coding Macro as Sting.

'Get a refernce to ThisWorbook Set oModule = xlsWorkbook.VBProject.VBComponents.Item ("ThisWorkbook") 'Create the code in a string Dim newCode newCode = "Public Sub TestThis(ByVal pParam as string)" + vbNewLine newCode = newCode + "Msgbox pParam" + vbNewLine newCode = newCode + "End Sub" + vbNewLine 'Add the code from a string oModule.CodeModule.AddFromString newCode 'Access the function we just added xlsWorkbook.TestThis "Tarun Lalwani"

Workingwith Modal dialog boxes:

QTP Recovery scenario does not help if no error occurs.

Here are possible API solutions:

FindWindow:  get window handle for a specific window.

FindWindowEx: get a child object of specified window, e.g. OK button in the dialog box

PostMessage: Send a message to a specific window’s message queue.

SetActiveWindow: Set the window active.

Method1: cannot used if not sure when window will appear.

To close non QTP message box, find the handle of dialog withtitle, get its child button to close the dialog and send the message to clickthat button:

'API declarations Extern.Declare micLong,"FindWindow","user32.dll","FindWindowA", _                 micString,micString Extern.Declare micLong,"FindWindowEx","user32.dll","FindWindowExA", _                 micLong,micLong,micString,micString Extern.Declare micLong,"PostMessage","user32.dll","PostMessageA", _                 micLong,micLong,micLong,micRef+micLong Extern.Declare micLong,"SetActiveWindow","user32.dll","SetActiveWindow", _                 micLong 'Constant for the Click event message for a button Private Const BN_CLICK = 245 'Note the window and button name are case sensitive sWindowName = "Test Window" sWindowButton = "OK" 'Get the window handle from window caption/title hwndWindow = Extern.FindWindow (vbNullString,sWindowName) 'If we find a non-zero handle If hwndWindow Then                'find the handle to the button inside the window                hwndButton = Extern.FindWindowEx(hwndWindow,0,vbNullString,sWindowButton)                If hwndButton Then                               Msgbox "Got the button, Activating the window and clicking the button"                               'Activate the window                               Extern.SetActiveWindow hwndWindow                               'Post the BN_CLICK message twice. We are doing it twice as                               'sometimes the first message is missed                               Extern.PostMessage hwndButton,BN_CLICK, 0, 0                               Extern.PostMessage hwndButton,BN_CLICK, 0, 0                Else     Msgbox "Cannot find the button"                End If Else                Msgbox "Cannot find the window" End If

Method2:  Write the code in VBS file and invoke itfrom QTP asynchronously using WSH Shell object.

‘Code in VBSà C:\AutoClick.vbs Const micLong = 3 Const micString = 8 Const micByRef = 32768 Set Extern = createObject("Mercury.ExternObj") Extern.Declare micLong,"FindWindow","user32.dll","FindWindowA", _                   micString,micString Extern.Declare micLong,"FindWindowEx","user32.dll","FindWindowExA", _                   micLong,micLong,micString,micString Extern.Declare micLong,"PostMessage","user32.dll","PostMessageA", _                   micLong,micLong,micLong,micRef+micLong Extern.Declare micLong,"SetActiveWindow","user32.dll","SetActiveWindow", _                   micLong 'Constant for the Click event message for a button Private Const BN_CLICK = 245 'Note the window and button name are case sensitive 'Get the WindowName and Button Name from the arguments 'specifi sWindowName = WScript.Arguments(0) sWindowButton = WScript.Arguments(1) 'Run the Script until the window is clicked atleast once While Not AutoClickButton(sWindowName,sWindowButton) Wend Set Extern = Nothing Private Function AutoClickButton(ByVal sWindowName, ByVal sWindowButton)                AutoClickButton = False                hwndWindow = Extern.FindWindow(vbNullString, sWindowName)                If hwndWindow Then                               hwndButton = Extern.FindWindowEx(hwndWindow, 0, vbNullString, sWindowButton)                               If hwndButton Then                                              Extern.SetActiveWindow hwndWindow                                              Extern.PostMessage hwndButton, BN_CLICK, 0, 0                                              Extern.PostMessage hwndButton, BN_CLICK, 0, 0                                              AutoClickButton = True                               End If                End If End Function

‘Code in QTP Set WshShell = CreateObject("WScript.Shell") sWindowName = """" & "Test Window" & """" sWindowButton = """" & "OK" & """" Return = WshShell.Run("C:\AutoClick.vbs "& sWindowName & " " & sWindowButton, 1, False ) ‘Code that may be pop up or message dialog…….. Set WshShell = Nothing