栅格重分类方法很多，在AE中有多种方式可以实现，使用地图代数（在RasterModel中实现），或者IReclassOp，或者Geoprocessor的方式都可以，甚至可以遍历栅格来实现，这是最原始的方式，不过也可能是最实用的。这里使用的是最原始的遍历栅格的方式。

        private void reclass(IRaster pRaster, float weight)
        {
            IRasterProps rasterProps = (IRasterProps)pRaster;

            //设置栅格数据起始点
            IPnt pBlockSize = new Pnt();
            pBlockSize.SetCoords(rasterProps.Width, rasterProps.Height);

            //选取整个范围
            IPixelBlock pPixelBlock = pRaster.CreatePixelBlock(pBlockSize);

            //左上点坐标
            IPnt tlp = new Pnt();
            tlp.SetCoords(0, 0);

            //读入栅格
              IRasterBandCollection pRasterBands = pRaster as  IRasterBandCollection;
            IRasterBand pRasterBand = pRasterBands.Item(0);

            IRawPixels pRawRixels = pRasterBands.Item(0) as IRawPixels;

            pRawRixels.Read(tlp, pPixelBlock);

            //将PixBlock的值组成数组
            System.Array pSafeArray = pPixelBlock.get_SafeArray(0) as System.Array;

            for (int y = 0; y < rasterProps.Height; y++)
            {
                for (int x = 0; x < rasterProps.Width; x++)
                {
                    //int value = Convert.ToInt32(pSafeArray.GetValue(x, y));
                    Byte value = Convert.ToByte(pSafeArray.GetValue(x, y));
                    if (value != 0)
                    {
                        pSafeArray.SetValue((Byte)(value * weight), x, y);
                    }
                }
            }

            pPixelBlock.set_SafeArray(0, pSafeArray);

            //编辑raster，将更新的值写入raster中
            IRasterEdit rasterEdit = pRaster as IRasterEdit;
            rasterEdit.Write(tlp, pPixelBlock);
            rasterEdit.Refresh();
        }