由于VJ(SE,95)到V8的变化较大，大部分V8以前的MDL程序需要作相应的改动,本文将对文件扫描这一问题进行讨论。下面是升级后的一段代码：&nbsp
…..&nbsp
pPoint->x=3020435529.5423102,&nbsp
pPoint->y=2645572566.3975053.&nbsp
lRangeUors=10000;&nbsp
#if&nbspdefined&nbsp(V8)&nbsp
>&nbsp
>&nbspRscanList.xlowlim&nbsp=&nbsp(long)(pPoint->x&nbsp-&nbsp);&nbsp
>&nbspRscanList.ylowlim&nbsp=&nbsp(long)(pPoint->y&nbsp-&nbsplRangeUors);&nbsp
>&nbspRscanList.zlowlim&nbsp=&nbsp(long)(pPoint->z&nbsp-&nbsplRangeUors);&nbsp
>&nbspRscanList.xhighlim&nbsp=&nbsp(long)(pPoint->x&nbsp+&nbsplRangeUors);&nbsp
>&nbspRscanList.yhighlim&nbsp=&nbsp(long)(pPoint->y&nbsp+&nbsplRangeUors);&nbsp
>&nbspRscanList.zhighlim&nbsp=&nbsp(long)(pPoint->z&nbsp+&nbsplRangeUors);&nbsp
>&nbsp
>&nbsp#else&nbsp
>&nbspRscanList.xlowlim&nbsp=&nbspmdlCnv_toScanFormat((long)&nbsppPoint->x&nbsp-&nbsp
lRangeUors);&nbsp
>&nbspRscanList.ylowlim&nbsp=&nbspmdlCnv_toScanFormat((long)&nbsppPoint->y&nbsp-&nbsp
lRangeUors);&nbsp
>&nbspRscanList.zlowlim&nbsp=&nbspmdlCnv_toScanFormat((long)&nbsppPoint->z&nbsp-&nbsp
lRangeUors);&nbsp
>&nbspRscanList.xhighlim&nbsp=&nbspmdlCnv_toScanFormat((long)&nbsppPoint->x&nbsp+&nbsp
lRangeUors);&nbsp
>&nbspRscanList.yhighlim&nbsp=&nbspmdlCnv_toScanFormat((long)&nbsppPoint->y&nbsp+&nbsp
lRangeUors);&nbsp
>&nbspRscanList.zhighlim&nbsp=&nbspmdlCnv_toScanFormat((long)&nbsppPoint->z&nbsp+&nbsp
lRangeUors);&nbsp
>&nbsp#endif&nbsp
…….&nbsp
可是程序在V8下运行时范围限制部起作用，这是为什么呢？察看一下RscanList结构的定义就知道了，原V7以前的版本xlowlim采用的时是32bit，而V8采用的时是64bit(int64),所以强制转换成long是不行的，应该转换为&nbsp
int64.&nbsp
另外，V8也提供了相应的函数使用起来特别方便，请参阅帮助文档。例如：&nbspmdlCnv_dRange3dToScanRange&nbsp，mdlCnv_dRangeToScanRange&nbsp等等。&nbsp