c# - 我在将 datagridview 传输到 Excel 时遇到问题

Question

我在下面的 datagridview 中出现错误的原因是什么？

System.InvalidCastException: The COM object of type '' Microsoft.Office.Interop.Excel.ApplicationClass' could not be assigned to interface type 'Microsoft.Office.Interop.Excel._Application'. This operation failed because the QueryInterface call in the COM component for the interface with the IID '{000208D5-0000-0000-C000-000000000046}' failed with the following error: Error loading type library / DLL. (HRESULT exception returned: 0x80029C4A (TYPE_E_CANTLOADLIBRARY)). '

我写的代码是:

saveFileDialog.InitialDirectory = "C:";
saveFileDialog.Title = "Save as Excel File";
saveFileDialog.FileName = "Data";
saveFileDialog.Filter = "Excel Files(2003)|*.xls|Excel Files(2007)|*.xlsx";

if (saveFileDialog.ShowDialog() != DialogResult.Cancel)
{
    Microsoft.Office.Interop.Excel.Application excelApp = new Microsoft.Office.Interop.Excel.Application();
    excelApp.Application.Workbooks.Add(Type.Missing);

    excelApp.Columns.ColumnWidth = 20;

    for (int i = 1; i < dgwReport.Columns.Count + 1; i++)
    {
        excelApp.Cells[1, i] = dgwReport.Columns[i - 1].HeaderText;
    }

    for (int i = 0; i < dgwReport.Rows.Count; i++)
    {
        for (int j = 0; j < dgwReport.Columns.Count; j++)
        {
            excelApp.Cells[i + 2, j + 1] = dgwReport.Rows[i].Cells[j].Value;
        }
    }

    excelApp.ActiveWorkbook.SaveCopyAs(saveFileDialog.FileName.ToString());
    excelApp.ActiveWorkbook.Saved = true;
    excelApp.Quit();
}

Answer 1

使用发布的代码，我没有得到你描述的错误......

excelApp.Application.Workbooks.Add(Type.Missing);

这在创建新工作簿时看起来是正确的。但是，当涉及到将数据写入工作簿时，它似乎有问题。问题是代码正在将数据写入 excelApp，这是不正确的。 excelApp 可以打开多个工作簿，每个工作簿可以有多个“工作表”。您需要指定要写入的“位置”(哪个工作表中的哪个工作簿)。

由于您正在创建一个新工作簿，因此您需要“添加”一个新工作表并写入该工作表而不是 excelApp。

我测试了下面的代码，它将数据正确写入新工作簿中的新工作表。

saveFileDialog.InitialDirectory = "C:";
saveFileDialog.Title = "Save as Excel File";
saveFileDialog.FileName = "Data";
saveFileDialog.Filter = "Excel Files(2003)|*.xls|Excel Files(2007)|*.xlsx";

Microsoft.Office.Interop.Excel.Application excelApp = null;
Microsoft.Office.Interop.Excel.Workbook workbook = null;
Microsoft.Office.Interop.Excel.Worksheet worksheet = null;

try {
   if (saveFileDialog.ShowDialog() != DialogResult.Cancel) {
    excelApp = new Microsoft.Office.Interop.Excel.Application();
    workbook = excelApp.Application.Workbooks.Add(Type.Missing);
    worksheet = workbook.ActiveSheet;
    excelApp.Columns.ColumnWidth = 20;
    for (int i = 1; i < dgwReport.Columns.Count + 1; i++) {
      worksheet.Cells[1, i] = dgwReport.Columns[i - 1].HeaderText;
    }
    for (int i = 0; i < dgwReport.Rows.Count; i++) {
      for (int j = 0; j < dgwReport.Columns.Count; j++) {
        worksheet.Cells[i + 2, j + 1] = dgwReport.Rows[i].Cells[j].Value;
      }
    }
    excelApp.ActiveWorkbook.SaveCopyAs(saveFileDialog.FileName.ToString());
    excelApp.ActiveWorkbook.Saved = true;
    workbook.Close();
    excelApp.Quit();
  }
}
catch (Exception ex) {
  MessageBox.Show("Excel write error: " + ex.Message);
}
finally {
  // release the excel objects to prevent leaking the unused resource
  if (worksheet != null)
    Marshal.ReleaseComObject(worksheet);
  if (workbook != null)
    Marshal.ReleaseComObject(workbook);
  if (excelApp != null)
    Marshal.ReleaseComObject(excelApp);
}