Sets the unit of measurement for the rulers used by those objects that use rulers.


#include "ltwrappr.h"

virtual L_INT LAnnRuler::SetUnit(uUnit, pUnitAbbrev, uPrecision, uFlags=0)


L_UINT uUnit

The unit of measure of the ruler. Possible values are:

Value Meaning
ANNUNIT_INCH [0x0000] inches
ANNUNIT_FEET [0x0001] feet
ANNUNIT_YARDS [0x0002] yards
ANNUNIT_MICROMETERS [0x0003] micrometers
ANNUNIT_MILLIMETERS [0x0004] millimeters
ANNUNIT_CENTIMETERS [0x0005] centimeters
ANNUNIT_METERS [0x0006] meters
ANNUNIT_TWIPS [0x0007] twips
ANNUNIT_POINTS [0x0008] points
ANNUNIT_PIXELS [0x0009] pixels
ANNUNIT_SMART_METRIC [0x000A] Smart Metric
ANNUNIT_SMART_ENGLISH [0x000B] Smart English

L_TCHAR * pUnitAbbrev

Character string containing the unit abbreviation string to be displayed after the distance. You can pass NULL to get the default abbreviations for the current unit of measurement.

L_UINT uPrecision

Number of digits to be displayed after the decimal place.

L_UINT uFlags

Flags that determine the object to process. You can combine values when appropriate by using a bitwise OR ( | ). The following are valid values:

Value Meaning
0 Process only the specified object.
ANNFLAG_SELECTED [0x0001] Process only objects that have the selected property set to TRUE. For getting and setting the selected property, use the LAnnotation::IsSelected and LAnnotation::SetSelected functions.
ANNFLAG_NOINVALIDATE [0x0010] Do not invalidate the affected rectangle in the window. Use this to avoid generating unwanted paint messages.


Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.


The following annotation objects utilize one or more rulers as part of the annotation:

In addition, the Automation object (ANNOBJECT_AUTOMATION) stores default ruler settings along with the other object default settings.

To determine the unit of measure for each ruler as well as its precision, call the LAnnAutomation::GetUnit function or the LAnnRuler::GetUnit function. The default unit of measure for Ruler, Polyruler, and Crossproduct objects is Smart English. With the smart units, the unit changes with the length. For example, if the length is 11 inches (assuming the default precision of 2 is being used), "11.00 in" displays whereas if the length is 15 inches, "1 ft 3.00 in" displays. Call the LAnnAutomation::SetUnit or the LAnnRuler::SetUnit function to set the unit of measurement and its precision for the ruler. The precision indicates how many digits to display to the right of the decimal point in the length.

Required DLLs and Libraries


Win32, x64.

See Also




L_INT LAnnRuler_SetUnitExample(LAnnRuler  * pAnnObject) 
	L_INT nRet; 
	L_SIZE_T uLen; 
   L_UINT uUnit; 
   L_TCHAR * pUnitAbbrev=NULL; 
   L_SIZE_T uPrecision; 
   L_TCHAR buf[180]; 
   L_DOUBLE dDistance; 
   LBuffer LeadBuffer ; 
   /* first, get unit abbreviation string len */ 
   uLen = pAnnObject->GetUnitLen(); 
   LeadBuffer.Reallocate((DWORD)uLen * sizeof(L_TCHAR)) ; 
   pUnitAbbrev = (L_TCHAR *)LeadBuffer.Lock(); 
   /* get the settings */ 
   uUnit = pAnnObject->GetUnit(pUnitAbbrev, &uPrecision,NULL); 
   /* and, get the distance */ 
   nRet = pAnnObject->GetDistance(&dDistance); 
	if(nRet != SUCCESS) 
		return nRet; 
   /* display current settings & distance in current unit of measurement */ 
   wsprintf(buf, TEXT("Unit: %d\nAbbrev: %s\nPrecision: %d\nDistance: %d\n"), 
				uUnit, pUnitAbbrev, uPrecision, dDistance); 
   MessageBox(NULL, buf, TEXT("Units"), MB_OK); 
   /* if unit is not inches, make it so */ 
   if(uUnit != ANNUNIT_INCHES) 
		nRet = pAnnObject->SetUnit(ANNUNIT_INCHES, TEXT("Inch"), 2, 0); 
		if(nRet != SUCCESS) 
			return nRet; 
	return SUCCESS; 
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