X Property Library Chapter 9
LabWindows/CVI Standard Libraries 9-24 © National Instruments Corporation
Return Values
The return value indicates the success or failure status of the function call. A negative value
indicates an error. The following table shows status values.
NoXErr 0 The function was successful.
InvalidParamXErr -1 NULL was passed to one or more parameters.
InvalidDisplayXErr -2 The display argument is not a valid display. This
argument must either be the predefined value
CVIXDisplay or be the value returned by
ConnectToXDisplay.
InvalidWindowXErr -3 The window argument is not a valid window.
InvalidPropertyError -4 The property argument is not a valid property handle.
This argument must be the value returned by
CreateXProperty.
TypeMismatchXErr -12 The actual X type of the property value on the window
does not match the type specified for property.
UnitMismatchXErr -13 The actual X format of the property value on the window
does not match the unit specified for property.
InvalidIndexXErr -14 The index specified is larger than the actual number of
property items on the window.
SizeMismatchXErr -15 The number of bytes in the property value is not a multiple
of the size specified for property.
InsuffMemXErr -19 There is insufficient memory to perform the operation.
GeneralXErr -20 An Xlib function failed for some unknown reason.
BrokenConnectionXErr -21 The connection to the X server was broken. This occurs if
the remote server terminated.
Parameter Discussion
display must either be the predefined value CVIXDisplay or be the value returned by
ConnectToXDisplay. Use CVIXDisplay if the window is on the same display used by
LabWindows/CVI.
For the window parameter, use CVIXRootWindow to access the default root window of the
display used by LabWindows/CVI. Use CVIXHiddenWindow to access the hidden window
associated with your application.
numberofItemsReturned will be less than or equal to the number of property items requested.
If the property does not exist on the window or there is no property value, this value will be 0.
You must check this value to determine if any property items were read.