Increment column header text Datagridview

Question

I have this code below that supposed to create a new column on datagridview everytimes a button is clicked, now that when a button is clicked a column named "New Column 1" will be generated but the thing is I was expecting for the "New Column 1" to be increment to "New Column 1" "New Column 2" "New Column 3" ... when a button is clicked for greater than once but "New Column 1" still appears even on multiple clicks.

What I've tried so far,

private void guna2Button4_Click_1(object sender, EventArgs e) {
        guna2DataGridView2.Columns.Clear();

        // Add new column
        string file_path = @"C:\MAIN_TEXT_LOCATION\" + label3.Text + "\" + label4.Text;
        using (StreamWriter swq = File.AppendText(file_path)) {
            var curr = 0;
            curr++;
            swq.Write("[" + "New Column " + (curr) + "]");
        }
        // Redefine data source
        retrieve_data();
}

I believe I have missing some crucial piece of code that I have to add in order to make it works but since I'm a novice I couldn't think further in order to make it works.

user_15760717 · Answer

Try This

  int curr = 0; 
    private void guna2Button4_Click_1(object sender, EventArgs e) {
            guna2DataGridView2.Columns.Clear(); 
            // Add new column
            string file_path = @"C:\MAIN_TEXT_LOCATION\" + label3.Text + "\" + label4.Text;
            using (StreamWriter swq = File.AppendText(file_path)) {
                
                curr++;
                swq.Write("[" + "New Column " + (curr) + "]");
            }
            // Redefine data source
            retrieve_data();
    }

user_5509738 · Answer

Here is a solution which gets the last number (int) in a string and increments the number by 1.

Add the following class to your project

public static class Helpers
{
    public static string NextValue(this string sender)
    {
        string value = Regex.Match(sender, "[0-9]+$").Value;
        return sender[..^value.Length] + (long.Parse(value) + 1)
            .ToString().PadLeft(value.Length, '0');
    }
}

Add a private int variable in the form private int _columnIndex = 0; to keep track of the last number for creating a new column.

In the form add using System.Text.RegularExpressions; then here in a button click event add a new column

public partial class Form1 : Form
{
    private int _columnIndex = 0;
    public Form1()
    {
        InitializeComponent();
    }

    private void NewColumnButton_Click(object sender, EventArgs e)
    {
        dataGridView1.Columns.Add(
            $"newColumnName{_columnIndex +1}", 
            $"New Column {_columnIndex}".NextValue());
        _columnIndex++;
    }
}

I expanded the columns in the screenshot after creating the columns manually.

Increment column header text Datagridview

2 Answers