无法编辑生成的Excel文件

Question

问题： 在已安装的Office 2010计算机中，我的应用程序必须将空的excel文件（文件A）复制到新的excel文件（文件B）并使用OpenXML库（V2.5）执行某些操作，最后保存到硬盘。之后，我打开文件B，只需添加一个小数据（例如：1）并保存并关闭它。 当我重新打开文件B时，excel抛出一个错误：Excel在'文件B'中找到了不可读的内容你想要恢复这个工作簿的内容......我无法打开它。 以下是我的代码：

static void Main(string[] args)
{
    ExportDataSet(@"C:\A.xlsx",@"C:\");
}
public static void Copy(String oldPath, String newPath)
{
    FileStream input = null;
    FileStream output = null;
    try
    {
        input = new FileStream(oldPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
        output = new FileStream(newPath, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite);

        var buffer = new byte[32768];
        int read;
        while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
        {
            output.Write(buffer, 0, read);
        }
    }
    catch (Exception e)
    {
    }
    finally
    {
        if (input != null)
        {
            input.Close();
            input.Dispose();
        }
        if (output != null)
        {
            output.Close();
            output.Dispose();
        }
    }

}

public static string ExportDataSet(string filePath, string path, int startRow = 10)
{
    var pathToSave = path;

    if (!Directory.Exists(pathToSave))
        Directory.CreateDirectory(pathToSave);
    var filename = pathToSave + Guid.NewGuid() + Path.GetExtension(filePath);
    Copy(filePath, filename);
    var fs = File.Open(filename, FileMode.Open);
    {
        using (var myWorkbook = SpreadsheetDocument.Open(fs, true))
        {
            var workbookPart = myWorkbook.WorkbookPart;
            var Sheets = myWorkbook.WorkbookPart.Workbook.GetFirstChild<Sheets>().Elements<Sheet>();
            var relationshipId = Sheets.First().Id.Value;
            var worksheetPart = (WorksheetPart)myWorkbook.WorkbookPart.GetPartById(relationshipId);
            var sheetData = worksheetPart.Worksheet.GetFirstChild<SheetData>();

            workbookPart.Workbook.Save();
            //workbookPart.Workbook.CalculationProperties = new CalculationProperties() { FullCalculationOnLoad = true };
        }
        fs.Close();
        fs.Dispose();
        return filename;
    }
}

I think the OpenXML library has something wrong. Do you have any ideas? please share to me, thank you so much.
Remarks:
1. the computer use Office 2010 to open Excel file
2. the file format is Excel workbook (.xlsx)
3. if the computer installed office with later version (2013, 2016), the problem was not appeared.

Answer 1

你的缓冲区读写逻辑是错误的。 The second parameter is where it starts to read or write并且您将它传递给零值，因此while的第二次迭代将覆盖第一次迭代中写入的内容，因此如果文件大于缓冲区大小，则会损坏数据。

您的代码应与此类似：

var buffer = new byte[32768];
int totalRead = 0; // Variable to track where to write in the next while iteration
int read;
while ((read = input.Read(buffer, totalRead, buffer.Length)) > 0)
{
    output.Write(buffer, totalRead, read);
    totalRead += read; // Add to totalRead the amount written so next iteration does append the content at the end.
}