Develop Reference

C# Interop Save to excel from datagridview without creating new file

I want to make changes to an existing file named "Original" in the directory "C:\Users\Twiga\Documents\VisualStudio2010\Projects\MarkSheetSystem\Original.xls".
Currently, I am only able to save the data that I have exported from my datagridview1 to a new file but that is not my intention.
Below is the code:
private void btnexcel_Click(object sender, EventArgs e)
{
Microsoft.Office.Interop.Excel._Application excel = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel._Workbook workbook = excel.Workbooks.Add(Type.Missing);
Microsoft.Office.Interop.Excel._Worksheet worksheet = null;
try
{
worksheet = workbook.ActiveSheet;
worksheet.Name = "Marksheet 1";
worksheet.Cells[12, 1] = dataGridView1.Rows[0].Cells[0].Value.ToString();
int cellRowIndex = 10;
int cellColumnIndex = 1;
//Loop through each row and read value from each column.
for (int i = 0; i < dataGridView1.Rows.Count; i++)
{
for (int j = 1; j < dataGridView1.Columns.Count - 1; j++)
{
// Excel index starts from 1,1. As first Row would have the Column headers, adding a condition check.
if (cellRowIndex == 0)
{
worksheet.Cells[cellRowIndex, cellColumnIndex] = dataGridView1.Columns[j].HeaderText;
}
else
{
worksheet.Cells[cellRowIndex, cellColumnIndex] = dataGridView1.Rows[i].Cells[j].Value.ToString();
}
cellColumnIndex++;
}
cellColumnIndex = 1;
cellRowIndex++;
}
//Getting the location and file name of the excel to save from user.
SaveFileDialog saveDialog = new SaveFileDialog();
saveDialog.Filter = "Excel files (*.xlsx)|*.xlsx|All files (*.*)|*.*";
saveDialog.FilterIndex = 2;
if (saveDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
workbook.SaveAs(saveDialog.FileName);
MessageBox.Show("The marksheet has been saved successfully!");
}
}
catch (System.Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
excel.Quit();
workbook = null;
excel = null;
}
}

Pertinent to your task, it would be better to export data to Excel Workbook from the DataGridView underlying DataTable (e.g. DataTable _dt = (DataTable)(datagridview1.DataSource)) as shown in the following C# sample code snippet:
/// <summary>
/// export DataTable to Excel (C#)
/// </summary>
internal static void Export2Excel(DataTable dataTable)
{
object misValue = System.Reflection.Missing.Value;
Microsoft.Office.Interop.Excel.Application _appExcel = null;
Microsoft.Office.Interop.Excel.Workbook _excelWorkbook = null;
Microsoft.Office.Interop.Excel.Worksheet _excelWorksheet = null;
try
{
// excel app object
_appExcel = new Microsoft.Office.Interop.Excel.Application();
// excel workbook object added
// can be replaced with _appExcel.Workbooks.Open(...)
_excelWorkbook = _appExcel.Workbooks.Add(misValue);
_excelWorksheet = _appExcel.ActiveWorkbook.ActiveSheet as Microsoft.Office.Interop.Excel.Worksheet;
// column names row (range obj)
Microsoft.Office.Interop.Excel.Range _columnsNameRange;
_columnsNameRange = _excelWorksheet.get_Range("A1", misValue).get_Resize(1, dataTable.Columns.Count);
// column names array to be assigned to _columnNameRange
string[] _arrColumnNames = new string[dataTable.Columns.Count];
for (int i = 0; i < dataTable.Columns.Count; i++)
{
// array of column names
_arrColumnNames[i] = dataTable.Columns[i].ColumnName;
}
// assign array to column headers range, make 'em bold
_columnsNameRange.set_Value(misValue, _arrColumnNames);
_columnsNameRange.Font.Bold = true;
// populate data content row by row
for (int Idx = 0; Idx < dataTable.Rows.Count; Idx++)
{
_excelWorksheet.Range["A2"].Offset[Idx].Resize[1, dataTable.Columns.Count].Value =
dataTable.Rows[Idx].ItemArray;
}
// Autofit all Columns in the range
_columnsNameRange.Columns.EntireColumn.AutoFit();
}
catch { throw; }
}
This will significantly improve the performance by exporting the entire data row at once instead of doing it cell-by-cell.
The only changes you have to make is to replace the line that adds new Workbook:
_excelWorkbook = _appExcel.Workbooks.Add(misValue);
with another one, opening the existing Excel File (e.g. "ExcelFilePath"), like:
_excelWorkbook = _appExcel.Workbooks.Open("ExcelFilePath",
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
Hope this may help.

Modify Interop Excel for Opening Existing File

I'm using Excel Interop for C# to export a datagridview to Excel and print it. I'm using this code:
try
{
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
excel.Application.Workbooks.Add(true);
int ColumnIndex = 0;
int rowIndex = -1;
foreach (DataGridViewRow row in dataGridView1.Rows)
{
rowIndex++;
ColumnIndex = 0;
foreach (DataGridViewColumn col in dataGridView1.Columns)
{
ColumnIndex++;
excel.Cells[rowIndex + 1, ColumnIndex] = row.Cells[col.Name].Value;
}
}
excel.Visible = true;
excel.DisplayAlerts = false;
Worksheet worksheet = (Worksheet)excel.ActiveSheet;
worksheet.Activate();
worksheet.Cells.Style.HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignCenter;
worksheet.Range[worksheet.Cells[1, 1], worksheet.Cells[1, 7]].Merge();
worksheet.Range[worksheet.Cells[2, 1], worksheet.Cells[2, 7]].Merge();
worksheet.Range[worksheet.Cells[3, 1], worksheet.Cells[3, 7]].Merge();
worksheet.Range[worksheet.Cells[4, 1], worksheet.Cells[4, 4]].Merge();
worksheet.Cells[1, 1].Font.Bold = true;
worksheet.Range["A1"].Cells.Font.Size = 15;
worksheet.Range["A4"].Cells.Font.Size = 15;
worksheet.Range["B7"].Cells.Font.Size = 15;
worksheet.Range["B8"].Cells.Font.Size = 15;
worksheet.Range["B9"].Cells.Font.Size = 15;
worksheet.Range["A11"].Cells.Font.Size = 15;
worksheet.Range["B13"].Cells.Font.Size = 15;
worksheet.PrintOut(Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
GC.Collect();
GC.WaitForPendingFinalizers();
excel.Quit();
}
catch (Exception ex)
{
MessageBox.Show("Error de exportación.");
}
It works fine, but I need to open an existing file to do this same thing to avoid reconfiguration of the printing margins. I checked other similar questions and tried to apply the "workBook = oXL.Workbooks.Open("path", ...);" but it can make it work. Any thoughts?

To open a file use the open method.
Microsoft.Office.Interop.Excel.Workbooks wkbks = null;
Microsoft.Office.Interop.Excel.Workbook wkbk = null;
wkbks = excel.Workbooks;
wkbk = wkbks.Open(xlsFileName);
At the end of your method you should do a cleanup on all your interop variables:
if (wkbk != null)
{
try
{
wkbk.Close(false);
}
catch
{
}
Marshal.FinalReleaseComObject(wkbk);
wkbk = null;
}

Export to Excel holding file open, and not exporting first datagrid

I am trying to export 2 datagridviews to excel but it is missing the last line of data for both of the sets of data grid views, I have checked the code and I cant see what I have done wrong? Also it is creating a temporary file when exporting and then locking the file and not exiting gracefully and only a reboot allows you to delete the file? Any help would be great code is below. For example if i save as test.xlsx I get 2 files ~$test.xlsx and test.xlsx and both both files are locked.
private void exprtbtn_Click(object sender, EventArgs e)
{
Microsoft.Office.Interop.Excel._Application app = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel._Workbook workbook = app.Workbooks.Add(Type.Missing);
try
{
// creating new Excelsheet in workbook
Microsoft.Office.Interop.Excel._Worksheet worksheet1 = null;
Microsoft.Office.Interop.Excel._Worksheet worksheet2 = null;
// get the reference of first sheet. By default its name is Sheet1.
// store its reference to worksheet
worksheet1 = workbook.Sheets["Sheet1"];
worksheet1 = workbook.ActiveSheet;
// changing the name of active sheet
worksheet1.Name = "Switch Totals";
// storing header part in Excel
for (int i = 1; i < switchtotalgrd.Columns.Count + 1; i++)
{
worksheet1.Cells[1, i] = switchtotalgrd.Columns[i - 1].HeaderText;
}
// storing Each row and column value to excel sheet
for (int i = 0; i < switchtotalgrd.Rows.Count - 1; i++)
{
for (int j = 0; j < switchtotalgrd.Columns.Count; j++)
{
worksheet1.Cells[i + 2, j + 1] = switchtotalgrd.Rows[i].Cells[j].Value.ToString();
}
}
// Adding second worksheet
int count = workbook.Worksheets.Count;
Excel.Worksheet addedSheet = workbook.Worksheets.Add(Type.Missing,
workbook.Worksheets[count], Type.Missing, Type.Missing);
// get the reference of first sheet. By default its name is Sheet1.
// store its reference to worksheet
worksheet2 = workbook.Sheets["Sheet2"];
worksheet2 = workbook.ActiveSheet;
// changing the name of active sheet
worksheet2.Name = "Itemised Extn";
// storing header part in Excel
for (int i = 1; i < fullresult.Columns.Count + 1; i++)
{
worksheet2.Cells[1, i] = fullresult.Columns[i - 1].HeaderText;
}
// storing Each row and column value to excel sheet
for (int i = 0; i < fullresult.Rows.Count - 1; i++)
{
for (int j = 0; j < fullresult.Columns.Count; j++)
{
if (fullresult.Rows[i].Cells[j].Value == null)
{
fullresult.Rows[i].Cells[j].Value = "NA";
}
worksheet2.Cells[i + 2, j + 1] = fullresult.Rows[i].Cells[j].Value.ToString();
}
}
// save the application
string fileName = String.Empty;
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.Filter = "Excel files |*.xls|All files (*.*)|*.*";
saveFileDialog1.FilterIndex = 2;
saveFileDialog1.RestoreDirectory = true;
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
fileName = saveFileDialog1.FileName;
workbook.SaveAs(fileName, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
}
else
return;
}
//Catch all errors.
catch (System.Exception)
{
}
finally
{
workbook = null;
app = null;
}
}

You probably might want to double-check your outer for loop again, e.g. for (int i = 0; i < fullresult.Rows.Count - 1; i++), shouldn't it be using less than and equal perhaps?
Since you are using Excel com interop, you will need to call this method to be able to release the resource after you are done with it, Marshal.ReleaseComObject.
A good practice is to use try{...}catch{...}finally{...}, and release com object in the finally block.

Reading data from excel 2010 using Microsoft.Office.Interop.Excel

I am not able to read data in Excel. Here is the code I am using:
using Excel = Microsoft.Office.Interop.Excel;
Excel.Application xlApp = new Excel.Application();
Excel.Workbook xlWorkbook = xlApp.Workbooks.Open(#"Book1.xlsx", 0, true, 5, "", "", true, Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
Excel._Worksheet xlWorksheet = (Excel._Worksheet)xlWorkbook.Sheets[1];
Excel.Range xlRange = xlWorksheet.UsedRange;
int rowCount = xlRange.Rows.Count;
int colCount = xlRange.Columns.Count;
for (int i = 1; i <= rowCount; i++)
{
for (int j = 1; j <= colCount; j++)
{
MessageBox.Show(xlWorksheet.Cells[i,j].ToString());
}
}
I get a message box that says something about System.__ComObject instead of a value.
How can I fix this?

I found the solution for above, here is the code:
string temp = (string)(xlRange.Cells[i, j] as Excel.Range).Value2;
MessageBox.Show(temp);

Haven´t tested it, but I think it should read
MessageBox.Show(xlRange.Cells[i,j].ToString());
or alternatively
MessageBox.Show(xlRange.Cells[i,j].Value.ToString());

Try this:
MessageBox.Show(xlRange.Cells[i][j].Value);

use the following function to get data as DATATABLE object for N'th sheet :
public DataTable GetWorkSheet(int workSheetID)
{
string pathOfExcelFile = fileFullName;
DataTable dt = new DataTable();
try
{
excel.Application excelApp = new excel.Application();
excelApp.DisplayAlerts = false; //Don't want Excel to display error messageboxes
excel.Workbook workbook = excelApp.Workbooks.Open(pathOfExcelFile, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); //This opens the file
excel.Worksheet sheet = (excel.Worksheet)workbook.Sheets.get_Item(workSheetID); //Get the first sheet in the file
int lastRow = sheet.Cells.SpecialCells(excel.XlCellType.xlCellTypeLastCell, Type.Missing).Row;
int lastColumn = sheet.Cells.SpecialCells(excel.XlCellType.xlCellTypeLastCell, Type.Missing).Column;
excel.Range oRange = sheet.get_Range(sheet.Cells[1, 1], sheet.Cells[lastRow, lastColumn]);//("A1",lastColumnIndex + lastRow.ToString());
oRange.EntireColumn.AutoFit();
for (int i = 0; i < oRange.Columns.Count; i++)
{
dt.Columns.Add("a" + i.ToString());
}
object[,] cellValues = (object[,])oRange.Value2;
object[] values = new object[lastColumn];
for (int i = 1; i <= lastRow; i++)
{
for (int j = 0; j < dt.Columns.Count; j++)
{
values[j] = cellValues[i, j + 1];
}
dt.Rows.Add(values);
}
workbook.Close(false, Type.Missing, Type.Missing);
excelApp.Quit();
}
catch (Exception ex)
{
System.Windows.Forms.MessageBox.Show(ex.Message, "Error", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);
}
return dt;
}

Try this code:
MessageBox.Show(((Excel.Range)xlRange.Cells[i,j]).Value2.ToString());
This code works sucessfully for me.

CSV export with interop

I'm using this code to generate an Excel file. It should be simple to change the export to CSV file, just by modifying a parameter in the saveAs call, but it doesn't work. Any ideea why ?
Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
xlApp.Visible = false;
if (xlApp == null)
{
MessageBox.Show("EXCEL could not be started. Check that your office installation and project references are correct.");
return false;
}
Workbook wb = xlApp.Workbooks.Add(XlWBATemplate.xlWBATWorksheet);
try
{
if (details != false)
{
//Workbook wb = xlApp.Workbooks.Add(XlWBATemplate.xlWBATWorksheet);
wb.Worksheets.Add();
Worksheet detailsWs = (Worksheet)wb.Worksheets[2];
for (int i = 0; i < dt.Columns.Count; i++)
{
detailsWs.Cells[1, i + 1] = dt.Columns[i].Caption;
}
}
Worksheet ws = (Worksheet)wb.Worksheets[1];
if (ws == null)
{
MessageBox.Show("Worksheet could not be created. Check that your office installation and project references are correct.");
}
for (int i = 0; i < dt.Columns.Count; i++)
{
ws.Cells[1, i + 1] = dt.Columns[i].Caption;
}
for (int i = 0; i < dt.Rows.Count; i++)
{
for (int j = 0; j < dt.Columns.Count; j++)
{
ws.Cells[i + 2, j + 1] = dt.Rows[i].ItemArray[j];
}
worker.ReportProgress((i * 100) / dt.Rows.Count);
}
wb.SaveAs(filename, XlFileFormat.xlCSV, Type.Missing, Type.Missing, Type.Missing, Type.Missing, XlSaveAsAccessMode.xlShared, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
wb.Close(true, filename);
return true;
}
catch (Exception ex)
{
throw ex;
}
finally
{
// Cleanup
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
GC.WaitForPendingFinalizers();
if (wb != null)
{
wb.Close(Type.Missing, Type.Missing, Type.Missing);
Marshal.FinalReleaseComObject(wb);
}
if (xlApp != null)
{
xlApp.Quit();
Marshal.FinalReleaseComObject(xlApp);
}
}

i used the old way. lines of strings, with commas

XlSaveAsAccessMode.xlShared is the reason. i don't know why but i get that error too.
I try changing XlSaveAsAccessMode.xlNoChange and XlSaveAsAccessMode.xlExclusive,
it worked!