mo数据操作数度提高的方法

<P>我发现当把图层文件加入到图层中以后，对其数据进行操作速度很慢。</P>
<P>特别是进行空间统计的时候，从一个原图层数据过滤出符合条件的数据添加到统计结果中，我采用下面方法，速度会提高好多。</P>
<P>//CreateShpFile中只创建图层，而不把它加入到MAP中。</P>
<P>CMoMapLayer CreateShpFile(CString ShpFilePath, int ShpFileStyle,vector<lpMoFieldInfo> fieldDesc)<BR>{<BR> Logf("创建SHAPE文件:%s.....",ShpFilePath);<BR> CMoDataConnection conn;<BR> if (!conn.CreateDispatch(TEXT("MapObjects2.DataConnection")))<BR> {<BR>  Logf("失败!Error:%s\n",TEXT("创建连接失败"));<BR>  return NULL;<BR> }<BR> CString strFileTitle( ShpFilePath );<BR> int idx = 0;<BR> while ( idx != -1 )<BR> {<BR>  idx = strFileTitle.Find( "\\" );<BR>  strFileTitle = strFileTitle.Right( strFileTitle.GetLength() - idx - 1 );<BR> }<BR> idx = ShpFilePath.Find( strFileTitle );<BR> CString strFilePath( ShpFilePath.Left( idx ) );<BR> conn.SetDatabase( strFilePath );<BR> if (!conn.Connect())<BR> {<BR>  Logf("失败!Error:%s\n",TEXT("连接失败"));<BR>  return NULL;<BR> }<BR> CMoTableDesc tDesc;<BR> if (!tDesc.CreateDispatch(TEXT("MapObjects2.TableDesc")))<BR> {<BR>  Logf("失败!Error:%s\n",TEXT("创建表失败"));<BR>  return NULL;<BR> }<BR> tDesc.SetFieldCount(fieldDesc.size());<BR> vector<lpMoFieldInfo>::const_iterator itor;<BR> int index = 0;<BR> for(itor = fieldDesc.begin();itor != fieldDesc.end();++itor)<BR> {<BR>  if((*itor)->fieldType == moString)<BR>  {<BR>   tDesc.SetFieldType(index,moString);<BR>   tDesc.SetFieldName(index, (*itor)->fieldName);<BR>   tDesc.SetFieldLength(index, (*itor)->fieldLength);<BR>  }<BR>  else if((*itor)->fieldType == moLong)<BR>  {<BR>   tDesc.SetFieldType(index,moLong);<BR>   tDesc.SetFieldName(index, (*itor)->fieldName);<BR>   tDesc.SetFieldPrecision(index, (*itor)->fieldPrecision);<BR>  }<BR>  else if((*itor)->fieldType == moDouble)<BR>  {<BR>   tDesc.SetFieldType(index,moDouble);<BR>   tDesc.SetFieldName(index,(*itor)->fieldName);<BR>   tDesc.SetFieldPrecision(index,(*itor)->fieldPrecision);<BR>   tDesc.SetFieldScale(index, (*itor)->fieldScale);<BR>  }<BR>  index++;<BR> }</P>
<P> VARIANT vt;<BR> vt.vt = VT_BOOL;<BR> vt.boolVal = VARIANT_FALSE;<BR> CMoGeoDataset Geoset(conn.AddGeoDataset(strFileTitle, ShpFileStyle,(LPDISPATCH)tDesc, vt, vt));</P>
<P> CMoMapLayer TempMapLayer;<BR> if (!TempMapLayer.CreateDispatch(TEXT("MapObjects2.MapLayer")))<BR> {<BR>  Logf("失败!Error:%s\n",TEXT("创建图层失败"));<BR>  return NULL;<BR> }</P>
<P> TempMapLayer.SetGeoDataset(Geoset);<BR> Logf("成功!\n");</P>
<P> return TempMapLayer;<BR>}</P>

<P> CMoMapLayer tempPolyLayer(CreateShpFile(tempPolyShpFile,moShapeTypePolygon,tempPolyFieldInfo));<BR> tempPolyLayer.SetCoordinateSystem(m_map->GetCoordinateSystem());<BR> CMoRecordset tempPolyResc = tempPolyLayer.GetRecords();</P>
<P>。。。。</P>
<P>tempPolyResc.AddNew();</P>
<P>tempPolyResc.Update();</P>
<P>....</P>

<P>看一下</P>

<P>我用C#，看不大懂你的。</P><img src="images/post/smile/dvbbs/em02.gif" />