How to save datagridview as csv file?

RD Design

Hi,

I have a datagridview windows form with some data.I want to export that as a csv file.Here is my code and it gives an error while export.My guess is becuase of some empty values in cells.How can I fix this issue?

public void writeCSV(DataGridView gridIn, string outputFile)
{
string filename = "";
SaveFileDialog sfd = new SaveFileDialog();
sfd.Filter = "CSV (*.csv)|*.csv";
sfd.FileName = "Output.csv";
if (sfd.ShowDialog() == DialogResult.OK)
{
MessageBox.Show("Data will be exported and you will be notified when it is ready.");
if (File.Exists(filename))
{
try
{
File.Delete(filename);
}
catch (IOException ex)
{
MessageBox.Show("It wasn't possible to write the data to the disk." + ex.Message);
}
}
int columnCount = dataGridView1.ColumnCount;
string columnNames = "";
string[] output = new string[dataGridView1.RowCount + 1];
for (int i = 0; i < columnCount; i++)
{
columnNames += dataGridView1.Columns[i].Name.ToString() + ",";
}
output[0] += columnNames;
for (int i = 1; (i - 1) < dataGridView1.RowCount; i++)
{
for (int j = 0; j < columnCount; j++)
{
output[i] += dataGridView1.Rows[i - 1].Cells[j].Value.ToString() + ",";
}
}
System.IO.File.WriteAllLines(sfd.FileName, output, System.Text.Encoding.UTF8);
MessageBox.Show("Your file was generated and its ready for use.");
}
}

6 Replies

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Satya Karki5y ago
Check below link:
https://www.aspsnippets.com/Articles/Export-GridView-To-Word-Excel-PDF-CSV-Formats-in-ASP.Net.aspx
Rijwan Ansari5y ago
Modify this part as shown:
for (int i = 1; (i - 1) < dataGridView1.RowCount; i++)
               {
                   for (int j = 0; j < columnCount; j++)
                   {
                       output[i] +=Convert.ToString(dataGridView1.Rows[i - 1].Cells[j].Value) + ",";
                   }
               }
This will handle null value conversion.
Jignesh Kumar5y ago
Hi,

Please check null for column null values,
public void writeCSV(DataGridView gridIn, string outputFile)
        {
            string filename = "";
            SaveFileDialog sfd = new SaveFileDialog();
            sfd.Filter = "CSV (*.csv)|*.csv";
            sfd.FileName = "Output.csv";
            if (sfd.ShowDialog() == DialogResult.OK)
            {
                MessageBox.Show("Data will be exported and you will be notified when it is ready.");
                if (File.Exists(filename))
                {
                    try
                    {
                        File.Delete(filename);
                    }
                    catch (IOException ex)
                    {
                        MessageBox.Show("It wasn't possible to write the data to the disk." + ex.Message);
                    }
                }
                int columnCount = dataGridView1.ColumnCount;
                string columnNames = "";
                string[] output = new string[dataGridView1.RowCount + 1];
                for (int i = 0; i < columnCount; i++)
                {
                    columnNames += dataGridView1.Columns[i].Name?.ToString() + ",";
                }
                output[0] += columnNames;
                for (int i = 1; (i - 1) < dataGridView1.RowCount; i++)
                {
                    for (int j = 0; j < columnCount; j++)
                    {
                        output[i] += dataGridView1.Rows[i - 1].Cells[j].Value?.ToString() + ",";
                    }
                }
                System.IO.File.WriteAllLines(sfd.FileName, output, System.Text.Encoding.UTF8);
                MessageBox.Show("Your file was generated and its ready for use.");
            }
        }
Camilo Vega5y ago
Add a "?" after Value. That worked for me.

output[i] += dataGridView1.Rows[i - 1].Cells[j].Value?.ToString() + ",";

Here is the full explanation:

https://stackoverflow.com/questions/58671879/how-can-fixed-this-erorr-system-windows-forms-datagridviewcell-value-get-return
Tapan Patel9y ago
I think the cell object for that specific row is not intialized. I would suggest to put null check before accessing the cell value for below line:
output[i] += dataGridView1.Rows[i - 1].Cells[j].Value.ToString() + ",";
Vivek Kumar9y ago
Please check with null before converting into the string as below.

str != null ? str.ToString() : String.Empty;

Here you can replace str with your code.