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<h1>Descend</h1><script>
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<p>ExtObjectContainer#descend method allows you to navigate from a persistent object to it's members without activating or instantiating intermediate objects.</p>
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<div class="FormattedSourceCode"><div class="fscHeader"><span class="fscFileName">UtilityExample.vb: <span class="fscMemberName">TestDescend</span></span></div><div class="fscCode"><pre ID="ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57"><div><!--
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--><span style="color: #008080;">01</span><img id="ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Open_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedBlockStart.gif" align="top" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Open_Text').style.display='none'; document.getElementById('ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Closed_Image').style.display='inline'; document.getElementById('ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Closed_Text').style.display='inline';"/><img id="ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Closed_Image" src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ContractedBlock.gif" align="top" style="display: none;" onClick="this.style.display='none'; document.getElementById('ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Closed_Text').style.display='none'; document.getElementById('ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Open_Image').style.display='inline'; document.getElementById('ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Open_Text').style.display='inline';"/><span style="color: #0000FF;">Public</span><span style="color: #000000;"> </span><span style="color: #0000FF;">Shared</span><span style="color: #000000;"> </span><span id="ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Closed_Text" style="border: solid 1px #808080; background-color: #FFFFFF; display: none;">Sub TestDescend()</span><span id="ResourcesReferenceTuningUtility_MethodsutilityVB.ZipsUtilityExample.Vb_UtilityExample.Vb_TestDescend_219_57_14_905_Open_Text"><span style="color: #0000FF;">Sub</span><span style="color: #000000;"> TestDescend()
</span><span style="color: #008080;">02</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> StoreSensorPanel()
</span><span style="color: #008080;">03</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> configuration </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IConfiguration </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.NewConfiguration()
</span><span style="color: #008080;">04</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> configuration.ActivationDepth(</span><span style="color: #800080;">1</span><span style="color: #000000;">)
</span><span style="color: #008080;">05</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> db </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IObjectContainer </span><span style="color: #000000;">=</span><span style="color: #000000;"> Db4oFactory.OpenFile(configuration, Db4oFileName)
</span><span style="color: #008080;">06</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Try</span><span style="color: #000000;">
</span><span style="color: #008080;">07</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> System.Console.WriteLine(</span><span style="color: #800000;">"</span><span style="color: #800000;">Object container activation depth = 1</span><span style="color: #800000;">"</span><span style="color: #000000;">)
</span><span style="color: #008080;">08</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> result </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> IObjectSet </span><span style="color: #000000;">=</span><span style="color: #000000;"> db.Get(</span><span style="color: #0000FF;">New</span><span style="color: #000000;"> SensorPanel(</span><span style="color: #800080;">1</span><span style="color: #000000;">))
</span><span style="color: #008080;">09</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> spParent </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> SensorPanel </span><span style="color: #000000;">=</span><span style="color: #000000;"> </span><span style="color: #0000FF;">CType</span><span style="color: #000000;">(result(</span><span style="color: #800080;">0</span><span style="color: #000000;">), SensorPanel)
</span><span style="color: #008080;">10</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> fields() </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> </span><span style="color: #0000FF;">String</span><span style="color: #000000;"> </span><span style="color: #000000;">=</span><span style="color: #000000;"> {</span><span style="color: #800000;">"</span><span style="color: #800000;">_next</span><span style="color: #800000;">"</span><span style="color: #000000;">, </span><span style="color: #800000;">"</span><span style="color: #800000;">_next</span><span style="color: #800000;">"</span><span style="color: #000000;">, </span><span style="color: #800000;">"</span><span style="color: #800000;">_next</span><span style="color: #800000;">"</span><span style="color: #000000;">, </span><span style="color: #800000;">"</span><span style="color: #800000;">_next</span><span style="color: #800000;">"</span><span style="color: #000000;">, </span><span style="color: #800000;">"</span><span style="color: #800000;">_next</span><span style="color: #800000;">"</span><span style="color: #000000;">}
</span><span style="color: #008080;">11</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Dim</span><span style="color: #000000;"> spDescend </span><span style="color: #0000FF;">As</span><span style="color: #000000;"> SensorPanel </span><span style="color: #000000;">=</span><span style="color: #000000;"> </span><span style="color: #0000FF;">CType</span><span style="color: #000000;">(db.Ext().Descend(</span><span style="color: #0000FF;">CType</span><span style="color: #000000;">(spParent, </span><span style="color: #0000FF;">Object</span><span style="color: #000000;">), fields), </span><span style="color: #0000FF;">Object</span><span style="color: #000000;">)
</span><span style="color: #008080;">12</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> db.Ext().Activate(spDescend, </span><span style="color: #800080;">5</span><span style="color: #000000;">)
</span><span style="color: #008080;">13</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> System.Console.WriteLine(spDescend)
</span><span style="color: #008080;">14</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">Finally</span><span style="color: #000000;">
</span><span style="color: #008080;">15</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> db.Close()
</span><span style="color: #008080;">16</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/InBlock.gif" align="top"/> </span><span style="color: #0000FF;">End</span><span style="color: #000000;"> </span><span style="color: #0000FF;">Try</span><span style="color: #000000;">
</span><span style="color: #008080;">17</span><span style="color: #000000;"><img src="../../../Utility/ActiPro.CodeHighligher/OutliningIndicators/ExpandedBlockEnd.gif" align="top"/> </span><span style="color: #0000FF;">End Sub</span></span></div></pre></div></div>
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<p>Navigating in this way can save you resources on activating only the objects you really need.</p></div>
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This revision (18) was last Modified 2006-11-13T16:09:14 by Tetyana.
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