Datagrid textbox change event how to get

ItemDataBound event of datagrid.
protected void DataGrid1_ItemDataBound(object sender, DataGridItemEventArgs e)
    {
        if (!Page.IsPostBack)
        {
            if (e.Item.ItemType == ListItemType.Item)
            {
                TextBox ddl = e.Item.FindControl("TextBox1") as TextBox;
                
                    ddl.TextChanged += new EventHandler(TextBox1_TextChanged);
              
            }
        }

    }

TextBox changed event
 protected void TextBox1_TextChanged(object sender, EventArgs e)
    {
        // Your code
    }
Make sure your TextBox AutopostBack property to true