PreviewItem方法发生灾“难性故障”

<P>我在一个多线程里执行ISymbologyStyleClass 对象的PreviewItem方法时发生“灾难性故障”，详细信息里说出在ESRI.ARCGIS.Control里，请高手给予帮助，谢谢！</P>
<P>我的代码如下，在最后一行发生错误</P><PRE>ISymbologyControl  symbologyControl = new SymbologyControlClass();
symbologyControl.StyleClass = esriSymbologyStyleClass.esriStyleClassFillSymbols;
symbologyControl.LoadStyleFile("e:\\ESRI.ServerStyle");
ISymbologyStyleClass symbologyStyleClass = symbologyControl.GetStyleClass(symbologyControl.StyleClass);
IStyleGalleryItem item =new ServerStyleGalleryItem();
item = this.symbologyStyleClass.GetItem(10);
try
{
    stdole.IPictureDisp picture =symbologyStyleClass.PreviewItem(item, imageSize.Width, imageSize.Height);

}</PRE>

哎，没人回答，好郁闷......<img src="images/post/smile/dvbbs/em08.gif" />

<P> try语句后面应该跟个捕捉错误的语句啊！比如：</P>
<P>catch(Exception ex) <BR> { <BR> Console.WriteLine(ex.Message); <BR> } <BR></P>