使用AcGiTextStyle得到字体的准确宽度

LoveArx

　　由于使用AcDbMtext的extents()方法，只能得到MTEXT的外框，得不到字体的准确宽度，下面是用AcGiTextStyle的解决方法，得到准确的字体宽度。


HOW TO GET A TEXT STRING'S ACTUAL WIDTH
Product AUTOCAD Author LEE,HENRY
Date 26-MAR-99 Document ID 29095
Expiration date Attachments
Keywords API_R14_OK; API_TAHOE_OK; ARX

Developer Consulting Group technical solution. Autodesk confidential, for ADN members only. Please read the disclaimer

Question


We are trying to determine the actual width of the text in an AcDbMText
entity. There is an extents() function which gives the width of the bounding
box. However What I need is the length of the text itself and not its
bounding box. Many times it so happens that the bounding box is much
larger than the actual text itself. Is there a way of doing that?


Answer


Yes, there is a way but not directly from AcDbMText methods. What you said is
true so we must look else where to find an solution. It is from AcGiTextStyle
which has a method called extents(). It gives you the actual width in an
AcGePoint2d.

Here is a code snippet which demonstrates how to obtain the string width from
a user input string.


void getTextStrWidth()
{
char str[132];
int rt = acedGetString(true, "/nEnter a string: ", str);
if(rt != RTNORM)
{
acutPrintf("/nInvalid input, try again.");
return;
}

AcGiTextStyle iStyle;
AcDbTextStyleTable* pTable = NULL;
AcDbTextStyleTableRecord* pRecord = NULL;
try{
ARXOK(curDoc()->database()->getTextStyleTable(pTable,
AcDb::kForRead));
const char styleName[] = "STANDARD";
ARXOK(pTable->getAt(styleName, pRecord, AcDb::kForRead));
ARXOK(fromAcDbTextStyle(iStyle, pRecord->objectId()));
pRecord->close();
pTable->close();
}
catch(const Acad::ErrorStatus es)
{
acutPrintf("/nError: %s", acadErrorStatusText(es));
pRecord->close();
pTable->close();
}
AcGePoint2d pt = iStyle.extents(str, Adesk::kFalse, _tcslen(str),
Adesk::kTrue);
// get the width
acutPrintf("/nText string width is: /t.", pt.x);
     // get the height too
     acutPrintf("/nText string height is: /t.", pt.y);
}

//declare the following inline function in a header file
inline void ARXOK(Acad::ErrorStatus what) throw(Acad::ErrorStatus)
{
    if (what!=Acad::eOk)
     throw what;
}


Note: You have to strip some format characters off an AcDbMText text string
which is some extra work. Otherwise, the width calculation above will not be
accurate.

To make the dimension meaningful for OUTLINETEXTMETRIC, you'll need to
translate the point from WCS to the screen pixel size using
acedCoordFromWorldToPixel().


Disclaimer

This information is derived from a response to a specific question sent to the Developer Consulting Group at Autodesk, and thus given its nature, is subject to change without notice. The information is provided to you on an "as is" basis, and you may use it only at your own risk. Autodesk is not responsible for its quality, nor shall it be liable for any damage or loss caused by your use of this information.

Top