Reading a text file into a DataGridView using C# (Visual Studio 2005)

Being a website owner, I am always interested in how my site is performing in the search engines and, for the time being, Google is still my main focus. As I am busy learning C# using Visual Studio 2005 beta, I thought it may be useful to write an application that shows me what people searched for when they found my website on google. Please be aware that this is a quick 'n dirty and is NOT an example of good programming standards at all. It does demonstrate the following though:

• How to read a text file in C#
• How to create and display a DataGridView programatically (instead of using Visual Studio's Form Designer)
• A very unprofessional method of breaking a string into columns

The reason I use this "unprofessional method" of formatting a string into columns in the DataGridView is because I am reading my website's log file from Internet Information Services (IIS 5). This log file is seperated by spaces and not TAB characters or fixed length. If the string was TAB seperated of fixed length columns, it would be much easier. Also, you may have problems with this if you have spaces in your filenames on your site.

Up and running
To test the application, download the sample of my logfile and copy it to the Bin\Debug directory of your Visual Studio project.

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Downloads
Example log file

• Create a new C# Windows.Forms project in Visual Studio
• Double-click on the form (Form1) to create a form1_load method (linked to the Load event of the form)
• Replace ALL the code in the code editor with the code below

Take note that you should replace all the code in the code editor and not just the form1_load method..

#region Using directives using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Windows.Forms; #endregion namespace SiteLogReader { partial class Form1 : Form { protected DataGridView dataGridView1 = null; DataTable tdt = new DataTable(); public Form1() { InitializeComponent(); } DataColumn getNewColumn(string ColName, string ColType) { //This function simply creates a new column to be used in the DataTable DataColumn dc = new DataColumn(); dc.ColumnName = ColName; dc.DataType = System.Type.GetType(ColType); return dc; } void CreateNewRow(string line) { //Create a DataRow based on the DataTable DataRow ARow = tdt.NewRow(); int ColStart; int ColEnd; string ColValue; //We know the first 19 characters of the line will be the date, //so use it as a starting point //Get the date from the line parameter ColValue = line.Substring(0, 19); //Assign the value to the Date column in the DataGridView ARow["Date"] = ColValue; //we start with the first " " (space character) after the date ColStart = 20; //Search for the next space ColEnd = line.IndexOf(" ", ColStart + 1); //Get the string between the 2 spaces and assign it to the DataGridView column ColValue = line.Substring(ColStart, ColEnd - ColStart); ARow["IP"] = ColValue; //Move one character on and repeat the process for the remaining columns ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColValue = line.Substring(ColStart, ColEnd - ColStart); ARow["Username"] = ColValue; //Skip one column as we do not want it in the DataGridView ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColValue = line.Substring(ColStart, ColEnd - ColStart); ARow["Port"] = ColValue; ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColValue = line.Substring(ColStart, ColEnd - ColStart); ARow["Method"] = ColValue; ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColValue = line.Substring(ColStart, ColEnd - ColStart); ARow["URL"] = ColValue; //Skip a couple of columns ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColStart = ColEnd + 1; ColEnd = line.IndexOf(" ", ColStart + 1); ColValue = line.Substring(ColStart, ColEnd - ColStart); ARow["Agent"] = ColValue; //Referer is the last column within the line, therefore we do not //search for the second space, but use the length of the string instead ColStart = ColEnd + 1; ColEnd = line.Length; //Make sure something was found, otherwise use an empty string if (ColEnd > ColStart && ColEnd > 0) { ColValue = line.Substring(ColStart, ColEnd - ColStart); } else { ColValue = ""; } ARow["Referer"] = ColValue; //I'm actually interested in what keywords and phrases people search //for when they are refered to my site by google, so here I cater //only for google, which starts its querystring with a "q=" //I already have the Referer in the ColValue String, so I work with that //instead of the line parameter string //Find "q=" in the string int qstart = ColValue.IndexOf("q=", 0); if (qstart > 0) { //skip over the "q=" portion qstart = qstart + 2; //Each parameter in a URL string is seperated by a "&", //so we look for the next & character //If we don't find an & character, we read to the end of the file int qEnd = ColValue.IndexOf("&", qstart); if (qEnd > 0) { //Instead of creating a new string variable, //we simply reuse the same one. ColValue = ColValue.Substring(qstart, qEnd - qstart); } else { ColValue = ColValue.Substring(qstart, ColValue.Length - qstart); } //If I knew how to use URLDecode in a Windows Forms application, //I would have done so, but I don't so here is a quick 'n dirty just to //get rid of %22 and the + sign ARow["SearchString"] = ColValue.Replace("%22", " ").Replace("+", " "); } //Now that we have all the values in the DataRow, we add the row to //the DataTable tdt.Rows.Add(ARow); } private void Form1_Load(object sender, EventArgs e) { this.WindowState = FormWindowState.Maximized; /* Add Columns to the datatable We're not using all these columns, but at first I thought they may be useful, so I left them in and simply hide them lower down */ tdt.Columns.Add(getNewColumn("Date", "System.DateTime")); tdt.Columns.Add(getNewColumn("IP", "System.String")); tdt.Columns.Add(getNewColumn("Username", "System.String")); tdt.Columns.Add(getNewColumn("Port", "System.String")); tdt.Columns.Add(getNewColumn("Method", "System.String")); tdt.Columns.Add(getNewColumn("URL", "System.String")); tdt.Columns.Add(getNewColumn("Agent", "System.String")); tdt.Columns.Add(getNewColumn("SearchString", "System.String")); tdt.Columns.Add(getNewColumn("Referer", "System.String")); int counter = 0; string line; //Open a text file for reading System.IO.StreamReader file = new System.IO.StreamReader(@"ex0410.txt"); // Read the file and add it to the datagridview, if google related while ((line = file.ReadLine()) != null) { if (line.StartsWith("#") != true && line.IndexOf("google") > 0 && line.IndexOf("bot.html") < 1 && line.IndexOf("mediapartners") < 1) { CreateNewRow(line); counter++; } } file.Close(); /* Create the DataGridView programatically */ dataGridView1 = new DataGridView(); this.Controls.Add(dataGridView1); dataGridView1.ColumnCount = 1; DataGridViewCellStyle style = dataGridView1.ColumnHeadersDefaultCellStyle; style.BackColor = Color.BlueViolet; style.ForeColor = Color.Black; style.Font = new Font(dataGridView1.Font, FontStyle.Bold); dataGridView1.EditMode = DataGridViewEditMode.EditOnEnter; dataGridView1.Name = "dataGridView1"; dataGridView1.Location = new Point(10, 10); dataGridView1.Size = new Size(this.Width - 20, this.Height - 200); dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.ColumnsDisplayedRows; dataGridView1.ColumnHeadersBorderStyle = DataGridViewHeaderBorderStyle.Raised; dataGridView1.CellBorderStyle = DataGridViewCellBorderStyle.Single; dataGridView1.GridColor = SystemColors.ActiveBorder; dataGridView1.RowHeadersVisible = false; dataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect; dataGridView1.MultiSelect = false; dataGridView1.BackgroundColor = Color.Honeydew; dataGridView1.Dock = DockStyle.Fill; //Assign the DataTable which we created earlier to the DataGridView dataGridView1.DataSource = tdt; //Hide some columns we're not interested in for (int i = 0; i < 8; i++) { dataGridView1.Columns[i].Visible = false; } //Resize columns for best fit dataGridView1.AutoSizeColumns (DataGridViewAutoSizeColumnCriteria.HeaderAndDisplayedRows); } } }

About the author
Dirk Wessels is a software developer and owner of www.getquotes-it.com. You may redistribute this article, but please keep this “About the author” section within the article together with an active link to www.getquotes-it.com