递归错误访问冲突

本文关键字:访问冲突 错误 递归 | 更新日期: 2023-09-27 18:22:33

我在C#上做了一个类,用DataTable:打开Excel

var excelApp = new ExcelInterop.Application();
excelApp.Workbooks.Add();
ExcelInterop._Worksheet workSheet = excelApp.ActiveSheet;
for (int i = 0; i < dt.Columns.Count; i++)
{
    workSheet.Cells[1, (i + 1)] = dt.Columns[i].ColumnName;
}
ExcelRecursive(dt, workSheet, 0, 0);
excelApp.Visible = true;

递归方法:

public void ExcelRecursive(DataTable dt, ExcelInterop._Worksheet ws, int i, int j)
{
    ws.Cells[(i + 2), (j + 1)] = dt.Rows[i][j];
    if (j + 1 < dt.Columns.Count)
        ExcelRecursive(dt, ws, i, j + 1);
    else if (i + 1 < dt.Rows.Count)
        ExcelRecursive(dt, ws, i + 1, 0);
}       

有70行的DataTables运行得很好,但更多的是应用程序停止,控制台上显示错误"访问违规":

程序"[3396]iisexpress.exe:program Trace"已退出,代码为0(0x0)。

程序"[3396]iisexpress.exe"已退出,代码为-103741819(0xc0000005)"访问冲突"。

我试试这个:

for (int i = 0; i < dt.Rows.Count; i++)
{
    // to do: format datetime values before printing
    for (int j = 0; j < dt.Columns.Count; j++)
    {
        workSheet.Cells[(i + 2), (j + 1)] = dt.Rows[i][j];
    }
}

这个:

public ExcelInterop._Worksheet ExcelRecursive(DataTable dt, ExcelInterop._Worksheet ws, int i, int j)
{
    ws.Cells[(i + 2), (j + 1)] = dt.Rows[i][j];
    if (j + 1 < dt.Columns.Count)
        return ExcelRecursive(dt, ws, i, j + 1);
    else if (i + 1 < dt.Rows.Count)
        return ExcelRecursive(dt, ws, i + 1, 0);
    else
        return ws;
}
    

但我的代码只适用于小型DataTables

递归错误访问冲突

我不能使用这种递归模式。

我的解决方案是EPPlus.dll

using OfficeOpenXml;

这种方法:

DataTable dt = Conversao.ConvertTo(list);
if (dt == null || dt.Columns.Count == 0)
    throw new Exception("ExportToExcel: Null or empty input table!'n");
OfficeOpenXml.ExcelPackage excel = new ExcelPackage();
ExcelWorksheet worksheet = excel.Workbook.Worksheets.Add("Plan 1");
worksheet.Cells["A1"].LoadFromDataTable(dt, true);
for (var i = 0; i < dt.Columns.Count; i++)
{
    if (dt.Columns[i].DataType == System.Type.GetType("System.DateTime"))
    {
        worksheet.Column(i + 1).Style.Numberformat.Format = "dd/mm/yyyy hh:mm:ss";
    }
}
Response.Clear();
Response.AddHeader("content-disposition", "attachment;filename=rel.xlsx");
Response.ContentType = "application/vnd.ms-excel";
Response.ContentEncoding = System.Text.Encoding.Default;
Response.Cache.SetCacheability(HttpCacheability.NoCache);
System.IO.MemoryStream stream = new System.IO.MemoryStream();
excel.SaveAs(stream);
stream.WriteTo(Response.OutputStream);
Response.End();

感谢grek40