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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-4FFA793B-9E57-5D59-B9A7-528F11C4852E" xml:lang="en"><title>Locating |
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13 a DLL</title><shortdesc>A polymorphic DLL is loaded by calling one of the <codeph>Load()</codeph> member |
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14 functions of an <codeph>RLibrary</codeph> object.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
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15 <p> <codeph>Load()</codeph> has three overloaded variants but they all behave |
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16 in a similar way. They are prototyped: </p> |
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17 <codeblock id="GUID-4A689563-CCC7-5C98-B75A-7A0E8DF31BBA" xml:space="preserve">TInt Load(const TDesC& aFileName,const TDesC& aPath,const TUidType& aType); |
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18 TInt Load(const TDesC& aFileName,const TUidType& aType); |
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19 TInt Load(const TDesC& aFileName,const TDesC& aPath=KNullDesC);</codeblock> |
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20 <p>The arguments determine how the DLL is to be found. The rules are summarised |
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21 as follows: </p> |
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22 <ul> |
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23 <li id="GUID-36D6A634-8CB3-57E9-BAB9-5C70C7EF106A"><p>If <codeph>aFileName</codeph> is |
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24 a fully defined filename, i.e. it includes a path specification, then the |
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25 contents of <codeph>aPath</codeph> are ignored and an attempt is made to load <codeph>aFileName</codeph>, |
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26 if specified; if this DLL cannot be found, then the load operation fails and |
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27 no further searching is done. </p> </li> |
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28 <li id="GUID-50FBE6FD-5AD3-5732-8A24-91A0B0B5ABB1"><p>if <codeph>aFileName</codeph> does |
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29 not have an extension, an extension of <filepath>.DLL</filepath> is assumed. </p> </li> |
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30 <li id="GUID-61547446-A954-5EF2-A77C-D0C4B2D0B4EB"><p>If <codeph>aFileName</codeph> contains |
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31 a file name but does <i>not</i> include a path specification (e.g. <filepath>EULIBDR1.DLL</filepath>), |
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32 then a search is done in the following locations in the order given: </p> <ul> |
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33 <li id="GUID-C0A63546-FE94-5B06-824D-83A4B77583BE"><p>the path defined in <codeph>aPath</codeph>, |
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34 if specified </p> </li> |
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35 <li id="GUID-72315ED1-4593-5D69-90DD-CE813A091F4B"><p>the system path <filepath>\sys\bin\</filepath> on |
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36 each attached drive. Drives are searched in the order: <filepath>C:</filepath> (the |
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37 device's main internal drive), then <filepath>Y:</filepath>, <filepath>X:</filepath>, <filepath>W:</filepath>, <filepath>V:</filepath>, <filepath>U:</filepath>, ..., <filepath>D:</filepath>, <filepath>B:</filepath>, <filepath>A:</filepath> and |
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38 finally, drive <filepath>Z:</filepath> (the ROM). </p> </li> |
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39 </ul> </li> |
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40 <li id="GUID-2EBA5162-3E09-510A-B65F-024CC5FF011E"><p>If <codeph>aType</codeph> is |
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41 specified, then the UIDType of the loaded DLL must match <codeph>aType</codeph>. |
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42 If <codeph>aType</codeph> is <codeph>KNullUid</codeph>, or the variant of <codeph>Load()</codeph> that |
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43 does not take <codeph>aType</codeph> is called, then the loaded DLL will have |
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44 the name <codeph>aFileName</codeph> and may have any UIDType. </p> </li> |
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45 </ul> |
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46 <p>Note that in WINS debug mode, the system path is <filepath>\epoc32\release\wins\udeb\</filepath> on |
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47 the current PC drive; in WINS release mode, the system path is <filepath>\epoc32\release\wins\urel\</filepath> on |
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48 the current PC drive. For WINSCW, the paths are the same as for WINS, except |
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49 that <filepath>wins\</filepath> becomes <filepath>winscw\</filepath>. </p> |
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50 <p>Note also that, in contrast with the usual convention, <codeph>aPath</codeph> specifies |
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51 a list of directories, each one separated by a semicolon. </p> |
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52 <p>See also: </p> |
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53 <ul> |
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54 <li id="GUID-2B04DF55-F0A3-5755-905D-8BB243A6BC36"><p> <xref href="GUID-98CC1E75-D2DE-3700-928C-7D530237ECBA.dita"><apiname>TFindFile</apiname></xref> </p> </li> |
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55 </ul> |
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56 </conbody></concept> |