CitrixWaitForScreen Function


This function uses screen appearance to synchronize subsequent user actions. Based on provided parameters, this function waits until the image in the specified screen region changes, matches the captured hash value(s), or does not match the hash value(s). To compare the actual screen region with the provided hash value(s), it is necessary that the color depth used during recording be identical to that used during replay.

The screen region can be specified absolutely or relatively to a window (by specifying a window handle). When only a window handle, and no position or size, is provided, the region specified by the window outline is used.

Note: Screen synchronization is only possible in Normal Mode (see CitrixInit). When used in Fast Mode this function waits a specified period of time (configurable through a call to CitrixSetOption). In the case of a timeout, error reporting can be prohibited with the bNoError parameter.

Include file



CitrixWaitForScreen( in nWindow  : number,
                     in nX       : number,
                     in nY       : number,
                     in nWidth   : number,
                     in nHeight  : number,
                     in sHash    : string optional,
                     in bUnequal : boolean optional,
                     in nTimeout : number optional,
                     in bNoError : boolean optional,
                     in nPolling : number optional ) : boolean;

Return value

  • true if successful

  • false otherwise

Parameter Description
nWindow Window handle returned by a call to CitrixWaitForWindowCreation. Use DESKTOP to specify a region relative to the desktop.
nX X coordinate of the left margin of the screen region.
nY Y coordinate of the top margin of the screen region.
nWidth Width of the region.
nHeight Height of the region.
sHash Captured hash value, to which the specified region should be compared (optional). This can also be a list of hash values separated by one of the following characters: , ; | /

Omit this parameter to synchronize on any change in the region.

bUnequal Set this parameter to true to wait for the specified region to mismatch the provided hash value.
nTimeout Specify the time in milliseconds to wait for the screen region to reach the correct appearance (optional). When this parameter is omitted or set to 0, the default timeout is used. The default value can be adjusted by profile settings ( Settings > Active Profile > Citrix > General > Synchronization timeout ) or an appropriate call to the CitrixSetOption function.
bNoError Set this parameter to true to prevent a timeout from raising an error. This is especially useful for controlling variable user reactions.
nPolling Specify the polling period in milliseconds that the Citrix Replay engine will wait to poll a screen for an update (0 means no polling). If omitted, the parameter is set to 1000. This parameter needs to be set to wait for any change in the specified region, rather than waiting for a specific change as defined by the sHash parameter. This setting overrides the CitrixSetOption(CITRIX_OPT_ScreenTextPolling) polling interval.


  transaction TMain
    CitrixInit(640, 480);
    CitrixConnect("citserver", "user", "password", "companydomain", COLOR_16bit);
    hWnd6 := CitrixWaitForWindowCreation("ICA Seamless Host Agent", MATCH_Exact, 0x94C800C4, 0, 0, 390, 223);
    CitrixWaitForWindow(hWnd6, EVENT_Activate);
    CitrixWaitForWindowCreation("Program Manager");
    CitrixMouseClick(214, 197, hWnd6, MOUSE_ButtonLeft);
    CitrixWaitForWindow(hWnd6, EVENT_Destroy);
    CitrixMouseDblClick(112, 16, DESKTOP, MOUSE_ButtonLeft);
    hWnd9 := CitrixWaitForWindowCreation("Microsoft Excel – Book*", MATCH_Wildcard, 0x15CF0000, -4, -4, 648, 460);
    CitrixWaitForScreen(hWnd9, 172, 137, 250, 148, "f100c8b71521fd895c23825b7f73a3a5|56a4337ff1aaf9ea477f0c5a2073dd2d", false);
    CitrixMouseClick(634, 9, hWnd9, MOUSE_ButtonLeft);
    CitrixWaitForWindow(hWnd9, EVENT_Destroy);
  end TMain;