問題背景：

話說，在ExcelReport的開發過程中，有一個比較棘手的問題：怎麼複製圖片呢？

當然，解決這個問題的第一步是：能使用NPOI提取到圖片及圖片的位置資訊。到這裡，一切想法都很順利。但NPOI到底怎麼提取圖片及圖片的位置資訊呢？NPOI能不能提取到圖片的位置資訊呢？

這是兩個問題。是兩個讓BaiGoogleDu幾近沉默的問題。但官方教程的評論中還是流露出了答案的蛛絲馬跡。

哇咔咔，這是我去看原始碼尋答案的的動力。

此處省去（N多字）… …，這裡宕掉了我三個晚上的時間。

不再累述，程式碼你懂的… ….

PicturesInfo.cs

public class PicturesInfo

{

    public int MinRow { get;set; }

    public int MaxRow { get;set; }

    public int MinCol { get;set; }

    public int MaxCol { get;set; }

    public Byte[] PictureData { get; private set; }

    public PicturesInfo(int minRow, int maxRow, int minCol, int maxCol,Byte[] pictureData)

    {

        this.MinRow = minRow;

        this.MaxRow = maxRow;

        this.MinCol = minCol;

        this.MaxCol = maxCol;

        this.PictureData = pictureData;

    }

}

NpoiExtend.cs

public static class NpoiExtend

{

    public static List<PicturesInfo> GetAllPictureInfos(this ISheet sheet)

    {

        return sheet.GetAllPictureInfos(null
 
,null,null,null);

    }

    public static List<PicturesInfo> GetAllPictureInfos(this ISheet sheet,int? minRow,int? maxRow,int? minCol,int? maxCol,bool onlyInternal = true)

    {

        if (sheet is HSSFSheet)

        {

            return GetAllPictureInfos((HSSFSheet)sheet,minRow,maxRow,minCol,maxCol,onlyInternal);

        }

        else if (sheet is XSSFSheet)

        {

            return GetAllPictureInfos((XSSFSheet)sheet, minRow, maxRow, minCol, maxCol, onlyInternal);

        }

        else

        {

            throw new Exception("未處理型別，沒有為該型別新增：GetAllPicturesInfos()擴充套件方法！");

        }

    }

    private static List<PicturesInfo> GetAllPictureInfos(HSSFSheet sheet,int? minRow, int? maxRow, int? minCol, int? maxCol, bool onlyInternal)

    {

        List<PicturesInfo> picturesInfoList = new List<PicturesInfo>();

        var shapeContainer = sheet.DrawingPatriarch as HSSFShapeContainer;

        if (null != shapeContainer)

        {

            var shapeList = shapeContainer.Children;

            foreach (var shape in shapeList)

            {

                if (shape is HSSFPicture && shape.Anchor is HSSFClientAnchor)

                {

                    var picture = (HSSFPicture)shape;

                    var anchor = (HSSFClientAnchor)shape.Anchor;

                    if (IsInternalOrIntersect(minRow, maxRow, minCol, maxCol, anchor.Row1, anchor.Row2, anchor.Col1, anchor.Col2, onlyInternal))

                    {

                        picturesInfoList.Add(new PicturesInfo(anchor.Row1, anchor.Row2, anchor.Col1, anchor.Col2, picture.PictureData.Data));

                    }

                }

            }

        }

        return picturesInfoList;

    }

    private static List<PicturesInfo> GetAllPictureInfos(XSSFSheet sheet, int? minRow, int? maxRow, int? minCol, int? maxCol, bool onlyInternal)

    {

        List<PicturesInfo> picturesInfoList = new List<PicturesInfo>();

        var documentPartList = sheet.GetRelations();

        foreach (var documentPart in documentPartList)

        {

            if (documentPart is XSSFDrawing)

            {

                var drawing = (XSSFDrawing)documentPart;

                var shapeList = drawing.GetShapes();

                foreach (var shape in shapeList)

                {

                    if (shape is XSSFPicture)

                    {

                        var picture = (XSSFPicture)shape;

                        var anchor = picture.GetPreferredSize();

                        if (IsInternalOrIntersect(minRow, maxRow, minCol, maxCol, anchor.Row1, anchor.Row2, anchor.Col1, anchor.Col2, onlyInternal))

                        {

                            picturesInfoList.Add(new PicturesInfo(anchor.Row1, anchor.Row2, anchor.Col1, anchor.Col2, picture.PictureData.Data));

                        }

                    }

                }

            }

        }

        return picturesInfoList;

    }

    private static bool IsInternalOrIntersect(int? rangeMinRow, int? rangeMaxRow, int? rangeMinCol, int? rangeMaxCol,

        int pictureMinRow, int pictureMaxRow, int pictureMinCol, int pictureMaxCol, bool onlyInternal)

    {

        int _rangeMinRow = rangeMinRow ?? pictureMinRow;

        int _rangeMaxRow = rangeMaxRow ?? pictureMaxRow;

        int _rangeMinCol = rangeMinCol ?? pictureMinCol;

        int _rangeMaxCol = rangeMaxCol ?? pictureMaxCol;

        if (onlyInternal)

        {

            return (_rangeMinRow <= pictureMinRow && _rangeMaxRow >= pictureMaxRow &&

                    _rangeMinCol <= pictureMinCol && _rangeMaxCol >= pictureMaxCol);

        }

        else

        {

            return ((Math.Abs(_rangeMaxRow - _rangeMinRow) + Math.Abs(pictureMaxRow - pictureMinRow) >= Math.Abs(_rangeMaxRow + _rangeMinRow - pictureMaxRow - pictureMinRow)) &&

            (Math.Abs(_rangeMaxCol - _rangeMinCol) + Math.Abs(pictureMaxCol - pictureMinCol) >= Math.Abs(_rangeMaxCol + _rangeMinCol - pictureMaxCol - pictureMinCol)));

        }

    }

}