[求助]如何在VC(AO) 中实现遍历像元与赋值

<P>vb中的部分程序:</P>
<P>Create PixelBlock with defined size<BR>Dim pBlock As IPixelBlock<BR>Set pBlock = pRawPixel.CreatePixelBlock(pSize)<BR> ' Get the SafeArray associated with the first band<BR> Dim pSafeArray As Variant<BR> pSafeArray = pBlock.SafeArray(0)<BR> ' Loop through the SafeArray and set value to each pixel<BR>  Dim I, J As Integer<BR>    For I = 0 To pSize.X - 1<BR>        For J = 0 To pSize.Y - 1<BR>            pSafeArray(I, J) = I + J<BR>        Next J<BR>    Next I</P>
<P>这段代码在VC中应该是怎样的呢? </P>

<P>高手帮下忙吧?</P>

<P>我这样尝试,可是结果是象元值都是0.</P>
<P> hr=pRawpixel->Read(pPnt,pPixelBlock);<BR>//  hr=pPixelBlock->PixelDataRef(0);</P>
<P><BR> SAFEARRAY *pa;<BR> hr=SafeArrayAllocDescriptor(2,;pa);//Allocates memory for a safe array descriptor<BR> pa->rgsabound[0].lLbound=0;<BR> pa->rgsabound[1].lLbound=0;<BR> pa->rgsabound[0].cElements=width;<BR> pa->rgsabound[1].cElements=height;<BR> pa->cbElements=sizeof(long);  <BR> hr=SafeArrayAllocData(pa);//Allocates memory for a safe array, based on a descriptor created with SafeArrayAllocDescriptor.<BR> <BR> long lDimension[2];<BR> <BR> <BR> VARIANT pPixelData;</P>
<P> VariantInit(;pPixelData);<BR> pPixelData.vt=VT_VARIANT|VT_ARRAY;</P>
<P> hr=pPixelBlock->get_SafeArray(0,;pPixelData);<BR> <BR> long i,j,x;</P>
<P><BR> for(i=0;i<=5;i++)<BR> { for(j=0;j<=5;j++)<BR>  {<BR>   lDimension[1]=i;//行<BR>   lDimension[0]=j;//列<BR>   x=(i+j) % 255;<BR>   hr=SafeArrayPutElement(pa,lDimension,;x);<BR>  }<BR> }<BR> pPixelData.parray=pa;<BR> hr=pPixelBlock->put_SafeArray(0,pPixelData);</P>
<P> hr=pRawpixel->Write(pPnt,pPixelBlock); </P>

<P>现在我有生成栅格文件</P>
<P>可是在ERDAS 里面打开的时候栅格值为0</P>
<P>而LUT却是有值的</P>
<P>这是事什么原因啊？</P>

<P>哎，一直以来就是自己一个人在这个主题下“自言自语”</P>
<P>不过还好</P>
<P>总算弄通了。</P>
<P>这个帖子算是结束了吧。说一下，所以没有值，是因为我在createdataset时数据类型不对</P>

hehe, i will try it following u have said