在webapplication中读取Excel中的图片

sunhahaha2 2010-02-02 04:06:25

下面的代码, 实现从excel中读取信息的功能.
其中, 读取Excel中的图片的功能(代码中注释掉的部分), 在Windows application下可以正常运行,
但在Web application中却有错误, 错误信息是IDataObject iData = Clipboard.GetDataObject();中的iData为null.
请问这是什么原因?
1) 是因为web application无法调用剪贴版? 如果是, 下面的代码该如何改写?
2) 还是权限没设置好? 如果是的话, 如何为web application添加相关操作的权限?

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Collections;

using Excel;

using System.Windows.Forms;

using System.Drawing;



namespace TestExcel

{

    public partial class _ReadExcel : System.Web.UI.Page

    {

        protected void Page_Load(object sender, EventArgs e)

        {

            lblResult.Text = string.Empty;

            LoadExcel();

        }



        private void LoadExcel()

        {

            string folderPath = Server.MapPath("~/App_data/");

            string fileName = folderPath + "MenuTemplate.xls";



            Excel.Application eApp = null;

            Excel.Workbook eBook = null;

            Excel.Worksheet eSheet = null;

            int startRow = 2;

            object Nothing = Type.Missing;



            eApp = new Excel.Application();

            eBook = eApp.Workbooks.Open(fileName, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing);



            for (int sheetIndex = 1; sheetIndex <= eBook.Worksheets.Count; sheetIndex++)

            {

                eSheet = (Excel.Worksheet)eBook.Worksheets[sheetIndex];

                if (eSheet.UsedRange.Rows.Count <= 1)

                    continue;



                string sheetName = eSheet.Name;

                lblResult.Text += System.Environment.NewLine + System.Environment.NewLine + "Sheet Name:" + sheetName;

                for (int rowIndex = startRow; rowIndex <= eSheet.UsedRange.Rows.Count; rowIndex++)

                {

                    string menuName = ((Excel.Range)eSheet.Cells[rowIndex, 'A' - 'A' + rowIndex]).Text.ToString();

                    if (menuName == "")

                        continue;

                    string description = ((Excel.Range)eSheet.Cells[rowIndex, 'B' - 'A' + rowIndex]).Text.ToString();



                    lblResult.Text += System.Environment.NewLine + "MenuName Description";

                    lblResult.Text += System.Environment.NewLine + menuName + " " + description;



                    ////Can only do it in windows application. Need more research

                    ////Read Image and save to disk

                    //if (eSheet.Shapes.Count > rowIndex - startRow)

                    //{

                    //    Excel.Shape s = eSheet.Shapes.Item(rowIndex - startRow + 1) as Excel.Shape;

                    //    s.CopyPicture(Appearance.Button, Excel.XlCopyPictureFormat.xlBitmap);　//Coty to memory

                    //    IDataObject iData = Clipboard.GetDataObject();

                    //    if (iData.GetDataPresent(DataFormats.Bitmap))

                    //    {

                    //        System.Drawing.Bitmap bit = (Bitmap)iData.GetData(DataFormats.Bitmap);

                    //        bit.Save(folderPath + rowIndex.ToString() + ".jpg");

                    //        bit.Dispose();

                    //    }

                    //}

                }

            }



            eApp.Quit();

            System.Runtime.InteropServices.Marshal.ReleaseComObject(eSheet);

            System.Runtime.InteropServices.Marshal.ReleaseComObject(eBook);

            System.Runtime.InteropServices.Marshal.ReleaseComObject(eApp);

            GC.Collect();

        }

    }

}