How to save datagridview as csv file?

Question

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.");
}
}

Rijwan Ansari · Answer

Modify this part as shown: for ( int i = 1; (i - 1) { for ( int j = 0; j { output[i] +=Convert.ToString(dataGridView1.Rows[i - 1].Cells[j].Value) + "," ; } } This will handle null value conversion.

Satya Karki · Answer

Check below link: https://www.aspsnippets.com/Articles/Export-GridView-To-Word-Excel-PDF-CSV-Formats-in-ASP.Net.aspx

Jignesh Kumar · Answer

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 { columnNames += dataGridView1.Columns[i].Name?.ToString() + "," ; } output[0] += columnNames; for ( int i = 1; (i - 1) { for ( int j = 0; 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 Vega · Answer

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 Patel · Answer

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 Kumar · Answer

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.