将datagridview数据导出到excel [excel文件应该是只读的]

Question

I want to export data from datagrid to excel file with below code I am exporting the data to excel but Iwant excel file of readonly which I am not getting with below code:

Microsoft.Office.Interop.Excel._Application app = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel._Workbook workbook = app.Workbooks.Add(Type.Missing);
Microsoft.Office.Interop.Excel._Worksheet worksheet = null;

app.Visible = true;

worksheet = workbook.ActiveSheet;
for (int i = 1; i < dg1.Columns.Count + 1; i++)
{
    worksheet.Cells[1, i] = dg1.Columns[i - 1].HeaderText;
}
for (int i = 0; i < dg1.Rows.Count - 1; i++)
{
    for (int j = 0; j < dg1.Columns.Count; j++)
    {
        if (dg1.Rows[i].Cells[j].Value != null)
        {
            worksheet.Cells[i + 2, j + 1] = dg1.Rows[i].Cells[j].Value.ToString();
        }
        else
        {
            worksheet.Cells[i + 2, j + 1] = "";
        }

    }
    worksheet.Columns.AutoFit(); 

Answer 1

Microsoft.Office.Interop.Excel._Application app = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel._Workbook workbook = app.Workbooks.Add(Missing.Value);
Microsoft.Office.Interop.Excel._Worksheet worksheet = workbook.ActiveSheet;
worksheet = workbook.ActiveSheet;

//app.Visible = true;

//getting all the columns from datagrid
for (int i = 1; i < dg1.Columns.Count + 1; i++)
{
    worksheet.Cells[1, i] = dg1.Columns[i - 1].HeaderText;
}
//getting row collection
for (int i = 0; i < dg1.Rows.Count - 1; i++)
{
    for (int j = 0; j < dg1.Columns.Count; j++)
        {
            if (dg1.Rows[i].Cells[j].Value != null)
            {
                worksheet.Cells[i + 2, j + 1] = dg1.Rows[i].Cells[j].Value.ToString();
            }
            else
            {
                worksheet.Cells[i + 2, j + 1] = "";
            }
            worksheet.Columns.AutoFit();                                        
        }
}

//to make the excel sheet readonly
((Excel.Worksheet)app.ActiveWorkbook.Sheets[1]).EnableSelection = Excel.XlEnableSelection.xlUnlockedCells;
((Excel.Worksheet)app.ActiveWorkbook.Sheets[1]).Protect(Password: protectionpasswprd, AllowFormattingCells: false);
app.ActiveWorkbook.SaveCopyAs("D:\\a.xls");
app.ActiveWorkbook.Saved = true;
app.Quit();