Using Win32 (WinAPI) Functions in Microsoft Visual FoxPro

ACOS3 Smart Card Class Library for Visual FoxPro

Thu, 09 Apr 2009 11:02:55 EST

ACOS3 VFP Class Library adds secure data echange with ACOS3 smart cards to Visual FoxPro applications.

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Wed, 01 Apr 2009 00:00:00 EST

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Code sample updated: Switching between keyboard layouts

Fri, 13 Feb 2009 11:24:47 EST

The form displays keyboard layouts available for the current process and allows switching between layouts.

If run in VFP9, this form also tracks switches between layouts initiated by hot keys (the form must be in focus at the moment of switch).

Code sample: Disconnecting USB Mass Storage Device programmatically

Wed, 11 Feb 2009 16:17:19 EST

USB Storage Devices can be disconnected (removed safely) in VFP code. This is the same safe procedure as the system utility uses.

Code sample: Reading and setting system access privileges for the current process

Thu, 05 Feb 2009 13:40:34 EST

A privilege is the right of an account, such as a user or group account, to perform various system-related operations on the local computer, such as shutting down the system, loading device drivers, or changing the system time.

API function: CM_Request_Device_Eject_Ex

Tue, 03 Feb 2009 16:07:06 EST

Prepares a local or a remote device instance for safe removal, if the device is removable.

API function: LookupPrivilegeName

Tue, 03 Feb 2009 14:10:16 EST

Retrieves the name that corresponds to the privilege represented on a specific system by a specified locally unique identifier (LUID).

API function: GetTokenInformation

Tue, 03 Feb 2009 13:39:53 EST

Retrieves a specified type of information about an access token.

Code sample: How to enable the SE_SHUTDOWN_NAME privilege for the application

Tue, 03 Feb 2009 11:15:14 EST

To shut down or to reboot the system (API calls ExitWindowsEx, InitiateShutdown and others) the process must have the SE_SHUTDOWN_NAME privilege (default behaviour on Vista).

API function: LookupPrivilegeValue

Mon, 02 Feb 2009 15:17:47 EST

Retrieves the locally unique identifier (LUID) used on a specified system to locally represent the specified privilege name.

API function: AdjustTokenPrivileges

Mon, 02 Feb 2009 13:41:15 EST

Enables or disables privileges in the specified access token.

API function: OpenProcessToken

Mon, 02 Feb 2009 13:19:59 EST

Opens the access token associated with a process.

Code sample: Starting a dialog box for connecting to network resources and passing input parameters

Mon, 02 Feb 2009 09:33:25 EST

This code sample is an extension of "#309. Starting a dialog box for connecting to network resources".

The code is written around the WNetConnectionDialog1 function and provides a better control of the network connection dialog through input parameters.

API function: WNetConnectionDialog1

Fri, 30 Jan 2009 14:18:01 EST

Brings up a general browsing dialog for connecting to network resources.

Code sample: How to control Adobe Reader 9.0 (SDI mode) from VFP application

Mon, 26 Jan 2009 13:58:28 EST

Each Adobe Reader 9 window is created from window class AcrobatSDIWindow and parented by the Windows Desktop. Enumeration of child windows of this class within the Desktop window returns the exact number of open Adobe Acrobat 9 documents.

The AdobeReaderSDIWindow class is able to virtually "click on" an item in the main menu of Adobe Reader 9 window and in this way to control some of the functionality.

Code sample: GDI+: Color Transparency

Mon, 19 Jan 2009 12:32:05 EST

With the GDI+, an image can be drawn on a Graphics object having a selected single color or a range of colors made transparent.

API function: GdipDrawImageRectRectI

Fri, 16 Jan 2009 18:40:01 EST

Draws an image optionally using a ImageAttributes object. This function can be used for drawing images with colors or color ranges made transparent.

API function: GdipCreateImageAttributes

Fri, 16 Jan 2009 18:13:07 EST

Creates new GDI+ ImageAttributes object.

Code sample: GDI+ fun: roach-infested desktop

Thu, 15 Jan 2009 16:35:48 EST

Bugs are frantically running for shelter in all directions all over the main VFP window. This hardly can scare a seasoned VFP developer. But unsuspecting user ought to beware.

API function: GdipDrawLineI

Thu, 15 Jan 2009 15:58:44 EST

Uses a pen to draw a line.

Code sample: GDI+: Creating thumbnails to preview images in a directory

Mon, 12 Jan 2009 12:22:48 EST

This code sample displays thumbnails for JPEG images found in a specified directory. The thumbnails on the form are dynamically highlighted following the movements of the cursor.

Code sample: GDI+: Scrolling through large image with the mouse

Fri, 09 Jan 2009 09:33:01 EST

The pictures taken with modern digital cameras are usually wider and higher than above average display resolution.

1920 by 1200 pixels, which requires fairly decent video card and monitor these days, is only 2.3 megapixel size. Uncropped 10.1 megapixel shot taken with Canon EOS 400D is 3888 by 2592 pixels -- roughly two times higher and wider.

API function: GdipSetClipRectI

Wed, 07 Jan 2009 17:53:20 EST

Sets the clipping region of this Graphics object by a specified rectangle.

API function: timeGetDevCaps

Wed, 07 Jan 2009 14:38:03 EST

Queries the timer device to determine its resolution.

Madame Tussauds Wax Museum, New York

Fri, 02 Jan 2009 17:07:56 EST

Visited recently...

Code sample: Enumerating devices installed on the local machine

Mon, 22 Dec 2008 10:42:30 EST

The PnP manager maintains a device tree that keeps track of the devices in the system.

The device tree contains information about the devices present on the system. The PnP manager builds this tree when the machine boots, using information from drivers and other components, and updates the tree as devices are added or removed.

API function: CM_Get_Sibling_Ex

Mon, 22 Dec 2008 10:39:41 EST

Obtains a device instance handle to the next sibling node of a specified device node, in a local or a remote machine"s device tree.

API function: CM_Locate_DevNode_Ex

Fri, 19 Dec 2008 12:29:58 EST

Obtains a device instance handle to the device node that is associated with a specified device instance identifier, on a local machine or a remote machine.

API function: CM_Connect_Machine

Fri, 19 Dec 2008 12:12:45 EST

Creates a connection to a remote machine

Code sample: How to view system icons for the classes installed on the local machine

Fri, 19 Dec 2008 10:27:59 EST

The bitmap images for the classes installed on the machine are stored in some system area. These images are more of a general kind and illustrate functionality groups rather than individual classes.

With a few API calls VFP application can access these images and display them in TreeView and ListView controls as icons.

API function: SetupDiGetClassImageIndex

Thu, 18 Dec 2008 18:04:27 EST

Retrieves the index within the class image list of a specified class.

API function: SetupDiDestroyClassImageList

Thu, 18 Dec 2008 17:49:43 EST

Destroys a class image list that was built by a call to SetupDiGetClassImageList or SetupDiGetClassImageListEx.

API function: SetupDiGetClassImageListEx

Thu, 18 Dec 2008 17:45:46 EST

Builds an image list of bitmaps for every class installed on a local or remote system.

Code sample: How to adjust monitor brightness (Vista, monitor with DDC support)

Wed, 10 Dec 2008 17:12:43 EST

The Monitor Configuration API was first made available in Windows Vista. These functions are applicable only if the monitor supports the Display Data Channel (DDC/CI) connection with the graphics adapter.

API function: SetMonitorBrightness

Wed, 10 Dec 2008 16:17:38 EST

Sets a monitor"s brightness value.

API function: GetMonitorBrightness

Wed, 10 Dec 2008 16:14:05 EST

Retrieves the minimum, maximum, and current brightness settings for a monitor.

API function: GetMonitorCapabilities

Wed, 10 Dec 2008 16:09:07 EST

Retrieves the configuration capabilities of a monitor. Call this function to find out which high-level monitor configuration functions are supported by the monitor.

Code sample: How to detect if additional monitor is connected and active

Tue, 09 Dec 2008 16:11:38 EST

Nowadays having two monitors connected to PC becomes more a rule than exception. This code sample explains how, through enumerating display devices and their properties, to detect all available monitors.

Code sample: How to remove a directory that is not empty

Mon, 08 Dec 2008 18:13:11 EST

As you know, the RMDIR generates an error message when an attempt made to remove a directory that is not empty. This example shows how to remove a directory with files based on the SHFileOperation call.

API function: SetEndOfFile

Mon, 08 Dec 2008 14:20:54 EST

Sets the physical file size for the specified file to the current position of the file pointer.

API function: ReplaceFile

Mon, 08 Dec 2008 13:24:38 EST

Replaces one file with another file, with the option of creating a backup copy of the original file.

API function: CopyFileTransacted

Thu, 04 Dec 2008 16:46:32 EST

Copies an existing file to a new file as a transacted operation, notifying the application of its progress through a callback function.

Code sample: Copying files as a transacted operation (Vista)

Thu, 04 Dec 2008 16:14:45 EST

Windows Vista offers transaction protection for various file operations: create, delete, copy, move and more.

API function: SCardTransmit

Mon, 27 Oct 2008 22:33:16 EST

Sends a service request to the smart card and expects to receive data back from the card.

API function: SCardConnect

Thu, 23 Oct 2008 15:45:06 EST

Establishes a connection (using a specific resource manager context) between the calling application and a smart card contained by a specific reader.

Code sample: Smart Card Database Query Functions

Wed, 22 Oct 2008 21:18:52 EST

Smart cards often are used in conjunction with security and personal privacy. The smart card resource manager manages the access to readers and smart cards.

Code sample: Using Multimedia Command Strings to play MIDI files

Mon, 14 Apr 2008 18:35:06 EST

The mciSendString can be used to play various media files including MIDI files.

Code sample: How to play MIDI notes

Wed, 09 Apr 2008 19:46:30 EST

Set the note in 0 to 127 range and the velocity (how hard the key is pressed) in 20 to 200+ range and press Enter.

API function: midiOutShortMsg

Wed, 09 Apr 2008 19:37:23 EST

Sends a short MIDI message to the specified MIDI output device.

API function: midiOutReset

Wed, 09 Apr 2008 19:26:27 EST

Turns off all notes on all MIDI channels for the specified MIDI output device.

Code sample: Using WM_COPYDATA for interprocess communication (VFP9)

Thu, 03 Apr 2008 09:25:33 EST

An application sends the WM_COPYDATA message to pass data to another application running on the same PC. The C# and VFP versions of this code sample are functionally identical. That allows exchanging data between .NET and VFP forms (applications).

Code sample: How to find when the application started

Wed, 26 Mar 2008 18:15:50 EST

The GetProcessTimes function among other output parameters returns the creation time of the process.

Code sample: Obtaining I/O counts for the current process

Wed, 26 Mar 2008 18:10:36 EST

The IO_COUNTERS structure contains I/O accounting information for a process or a job object. For a job object, the counters include all operations performed by all processes that have ever been associated with the job, in addition to all processes currently associated with the job.

API function: GetProcessVersion

Wed, 26 Mar 2008 17:21:24 EST

Retrieves the major and minor version numbers of the system on which the specified process expects to run.

API function: GetProcessTimes

Wed, 26 Mar 2008 17:21:07 EST

Retrieves timing information for the specified process.

Code sample updated: Round FoxPro form

Sat, 22 Mar 2008 11:10:54 EST

C# version has been added to this and two other code samples.

API function: JetDeleteTable

Fri, 11 Jan 2008 17:06:47 EST

Deletes a table in an ESE database.

API function: JetOpenTable

Fri, 11 Jan 2008 17:04:02 EST

Opens a cursor on an existing table.

API function: JetCloseTable

Fri, 11 Jan 2008 17:01:19 EST

Closes an open table in a database. The table is a temporary table or a normal table.

API function: JetCreateTable

Fri, 11 Jan 2008 16:58:01 EST

Creates an empty table in an ESE database.

API function: JetDetachDatabase

Fri, 11 Jan 2008 16:53:42 EST

Releases a database file that was previously attached to a database session.

API function: JetCloseDatabase

Fri, 11 Jan 2008 16:50:28 EST

Closes a database file that was previously opened with JetOpenDatabase.

API function: JetCreateDatabase

Fri, 11 Jan 2008 16:47:17 EST

Creates and attaches a database file to be used with the ESE database engine.

API function: JetCreateInstance

Fri, 11 Jan 2008 13:48:18 EST

Allocates a new instance of the database engine for use in a single process.

API function: JetEndSession

Tue, 08 Jan 2008 18:01:21 EST

Ends the session, and cleans up and deallocates any resources associated with the specified session.

API function: JetBeginSession

Tue, 08 Jan 2008 17:56:09 EST

Starts new ESE session and initializes and returns an ESE session handle

API function: JetInit

Tue, 08 Jan 2008 17:49:56 EST

Puts the database engine into a state where it can support application use of database files.

API function: JetTerm

Tue, 08 Jan 2008 17:49:45 EST

Initiates the shutdown of an instance that has been initialized by JetInit.

API function: if_nametoindex

Tue, 08 Jan 2008 10:55:25 EST

Converts the ANSI interface name for a network interface to the local index for the interface.

API function: if_indextoname

Tue, 08 Jan 2008 10:52:08 EST

Converts the local index for a network interface to the ANSI interface name.

API function: GetTcp6Table

Tue, 08 Jan 2008 10:31:27 EST

Retrieves the TCP connection table for IPv6.

API function: GetWindowRgnBox

Fri, 04 Jan 2008 15:19:55 EST

Retrieves the dimensions of the tightest bounding rectangle for the window region of a window.

API function: PaintDesktop

Fri, 04 Jan 2008 15:09:21 EST

Fills the clipping region in the specified device context with the desktop pattern or wallpaper.

API function: GdiSetBatchLimit

Fri, 04 Jan 2008 13:56:15 EST

Sets the maximum number of function calls that can be accumulated in the calling thread`s current batch. The system flushes the current batch whenever this limit is exceeded.

API function: GdiGetBatchLimit

Fri, 04 Jan 2008 13:51:41 EST

Returns the maximum number of function calls that can be accumulated in the calling thread`s current batch.

API function: GdiFlush

Fri, 04 Jan 2008 13:50:25 EST

Flushes the calling thread`s current batch.

API function: GetProductInfo

Wed, 26 Dec 2007 14:44:45 EST

Retrieves the product type for the operating system on the local computer, and maps the type to the product types supported by the specified operating system.

API function: GetNativeSystemInfo

Wed, 26 Dec 2007 14:20:47 EST

Retrieves information about the current system to an application running under WOW64.

Visits from MS crawler using regular agent string

Tue, 09 Oct 2007 14:07:09 EST

Last several weeks an MS crawler is hitting my website coming from ip range of 65.55.165.10 to approx. 65.55.165.125.

An interesting thing that the agent parameter is a regular one:
Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322)
supposedly pointing at an average web user.

A typical query string look like this:
http://search.live.com/results.aspx?q=functions

The robot's searches are mostly too general and repetitive: functions, foxpro, using, process, windows, registry, connections, language, socket and so on.

http://www.who.is/whois-ip/ip-address/65.55.165.76/

Code sample: How to display a Print property sheet

Thu, 04 Oct 2007 15:43:39 EST

The Print property sheet is a standard user interface that enables the user to specify the properties of a particular print job.

API function: PrintDlgEx

Thu, 04 Oct 2007 15:31:51 EST

The PrintDlgEx function displays a Print property sheet that enables the user to specify the properties of a particular print job.

API function: PrintDlgEx

Thu, 04 Oct 2007 15:31:51 EST

The PrintDlgEx function displays a Print property sheet that enables the user to specify the properties of a particular print job.

Code sample updated: Reading records in Windows Event logs

Sun, 09 Sep 2007 20:45:33 EST

With Event Viewer, users can monitor events recorded in the Application, Security, and System logs.

API function: DeregisterEventSource

Sun, 09 Sep 2007 20:42:25 EST

Closes a write handle to the specified event log.

API function: RegisterEventSource

Sun, 09 Sep 2007 20:40:26 EST

Retrieves a registered handle to the specified event log.

API function: ReportEvent

Sun, 09 Sep 2007 20:35:27 EST

Writes an entry at the end of the specified event log.

API function: GetEventLogInformation

Sun, 09 Sep 2007 20:28:34 EST

Retrieves information about the specified event log.

API function: ClearEventLog

Sun, 09 Sep 2007 20:25:08 EST

Clears the specified event log, and optionally saves the current copy of the log to a backup file.

API function: SetFilePointerEx

Mon, 20 Aug 2007 17:51:44 EST

Moves the file pointer of the specified file.

Watch video: FTP Class Library for Visual FoxPro -- getting started

Fri, 22 Jun 2007 00:23:35 EST

When a control from the FTP class library is dropped on VFP form, the form immediately turns into convenient FTP browser.

Solution added: FTP Class Library for Visual FoxPro

Fri, 22 Jun 2007 00:21:11 EST

The solution presents Visual FoxPro class library that wraps the set of FTP functions in the Microsoft® Win32® Internet (WinInet) API library.

New format of code samples introduced on the site: solutions

Fri, 22 Jun 2007 00:11:39 EST

What we call a solution is more than an advanced code sample. It is an entity containing more than one file, for example, a class library. Solution is meant to be a building block turn-key ready for inclusion in VFP developer's project.

API function: WTSQuerySessionInformation

Fri, 08 Jun 2007 16:35:26 EST

Retrieves session information for the specified session on the specified terminal server. It can be used to query session information on local and remote terminal servers.

Code sample updated: How to display a user-defined icon in the MessageBox dialog

Wed, 30 May 2007 16:43:31 EST

Shell32.dll contains several dozens system icons. Each of them can be easily displayed on MessageBox dialog form via MessageBoxIndirect API call.

Code sample: How to view icons stored in executable files (Icon Viewer) - II

Fri, 25 May 2007 21:54:26 EST

An API ImageList object (different from ImageList ActiveX control) is created and populated with the icons extracted from specified executable or library file. Then the ImageList is linked to a ListView control on the form. Each item in the ListView represents an icon.

Code sample: System Image List Viewer

Fri, 25 May 2007 17:01:44 EST

The OS creates the System Image List for each running process, with the process mainly responsible for populating the list with ListImage items via SHGetFileInfo calls or IExtractIcon Interface and may be by some other means.

Code sample updated: Enumerating files opened on the network

Fri, 25 May 2007 10:54:52 EST

The NetFileEnum function returns information about some or all open files on a server in an array of FILE_INFO_3 or FILE_INFO_2 structures.

Rewritten from scratch to become functional.

User contributed notes, rules changed

Fri, 25 May 2007 08:43:16 EST

Due to constant attention from comment spammers the rules of posting user contributed comments to the articles have changed. Starting recently, only subscribers can do that.

API function: ImageList_GetImageCount

Thu, 24 May 2007 18:45:53 EST

Retrieves the number of images in an image list.

API function: ImageList_Remove

Thu, 24 May 2007 18:44:34 EST

Removes an image from an image list.

API function: ImageList_Add

Thu, 24 May 2007 18:44:25 EST

Adds an image or images to an image list.

API function: ImageList_GetIconSize

Thu, 24 May 2007 18:43:42 EST

Retrieves the dimensions of images in an image list. All images in an image list have the same dimensions.

API function: ImageList_Create

Thu, 24 May 2007 18:40:51 EST

Creates a new image list.

API function: ImageList_Destroy

Thu, 24 May 2007 18:35:06 EST

Destroys an image list.

Code sample: Displaying the associated icons and descriptions for files and folders

Thu, 17 May 2007 18:48:21 EST

When the list of files and folders is to be displayed inside a VFP form, the ListBox VFP control and the ListView ActiveX control are probably the first two candidates for the job.

The ListBox`s presentation style can only be described as the minimalistic :) , while the ListView shows items in much fancier manner, and can even accompany each file and folder with an icon.

And an imminent question arises: where are those icons stored and how to put them to work?

API function: Shell_GetImageLists

Mon, 14 May 2007 11:45:49 EST

Retrieves system image lists for large and small icons -- undocumented.

API function: SHGetFileInfo

Sat, 12 May 2007 20:15:49 EST

Retrieves information about an object in the file system, such as a file, a folder, a directory, or a drive root.

The most obvious application for this function is obtaining the default icon (HICON handle) for a given file type.

Syntax coloring on web pages with GeSHi - Generic Syntax Highlighter

Tue, 08 May 2007 08:59:33 EST

Since yesterday news2news web site displays all code samples in colored syntax, including VFP, VB.Net, C#, C++ and WMI versions.

The web pages definitely look less dull, which is achieved with a help of GeSHi - Generic Syntax Highlighter plus some minor tweaks on top.

Code sample: Displaying the color pallete stored in an image file

Tue, 01 May 2007 20:44:14 EST

Depending on its bit per pixel mode, an image file can store a color palette inside its data. GDI+ functions GdipGetImagePalette and GdipGetImagePaletteSize allow to retrieve the palette in a form of ColorPalette structure.