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SGML formating Issue

I have an requirement to read the SGML file and replace if the symbol like comma(,) or full stop (.) then I need to change the symbols and save with the same SGML file itself but I am facing the format issue after replacing the content.
Below is my code and my final output would be store with the same .sgm format.
The below code is working but after replacing the values the output format is differs. Can you suggest for this scenario
Main method:
string resultValue = HTMLToEntity(ReplaceSGML(sbContent.ToString()));
StringReader sr = new StringReader(resultValue.ToString());
SgmlReader reader = new SgmlReader();
reader.WhitespaceHandling = WhitespaceHandling.All;
reader.CaseFolding = Sgml.CaseFolding.ToLower;
reader.InputStream = sr;
StringWriter sw = new StringWriter();
XmlTextWriter w = new XmlTextWriter(sw);
w.Formatting = System.Xml.Formatting.Indented;
w.WriteStartDocument();
reader.Read();
while (!reader.EOF)
{
w.WriteNode(reader, true);
}
//File.WriteAllText(#"C:\Output\test.sgm", );
w.Flush();
w.Close();
Method : ReplaceSGML
private static string ReplaceSGML(string html)
{
XmlDocument xml = new XmlDocument();
xml.Load(_xmlEnglishPath);
XmlNodeList resources = xml.SelectNodes("root/data");
_htmlEnglishDictonaries = new Dictionary<string, string>();
_htmlEnglishDictonaries.Add(";", "{After1Space}"); // replacing semicolon into {After1space}
_htmlEnglishDictonaries.Add(":", "{Before1Space}"); // replacing colon into {Before1Space}
_htmlEnglishDictonaries.Add(".", "{Before1Space}"); // replacing . into {Before1Space}
string line = string.Empty;
StringReader reader = new StringReader(html);
while (reader.Peek() > -1)
{
line = reader.ReadLine();
foreach (var events in _htmlEnglishDictonaries)
{
if (line.Contains(events.Key))
{
// Rule should be implement
// <!-- Replacetext 1.{After1Space}, 2.{Before1Space}, 3.{NoSpace}, 4. {After1LetterCaps} -->
int idx;
if (events.Value.ToLower().Trim() == "{after1space}")
{
idx = line.IndexOf(events.Key) + events.Key.Length;
if (line[idx].ToString() != " ")
{
line = line.Replace(events.Key, events.Key + " ");
}
}
if (events.Value.ToLower().Trim() == "{before1space}")
{
idx = line.IndexOf(events.Key);
if (line[idx].ToString() != " ")
{
line = line.Replace(events.Key, " " + events.Key);
}
}
if (events.Value.ToLower().Trim() == "{before1space},{after1space}")
{
idx = line.IndexOf(events.Key);
if (line[idx].ToString() != " ")
{
line = line.Replace(events.Key, " " + events.Key + " ");
}
}
if (events.Value.ToLower().Trim() == "{nospace}")
{
idx = line.IndexOf(events.Key);
if (line[idx].ToString() != " ")
{
line = line.Replace(events.Key, " " + events.Key);
}
}
if (events.Value.ToLower().Trim() == "{after1lettercaps}")
{
idx = line.IndexOf(events.Key) + events.Key.Length;
if (line[idx].ToString() != " ")
{
if (line[idx + 1].ToString() != " ")
{
line = line.Replace(events.Key, " " + events.Key + line[idx + 1].ToString().ToUpper());
}
else
{
line = line.Replace(events.Key, " " + events.Key);
}
}
}
}
}
}
return line.ToString();
}
Thanks in advance

The best and right way to close StreamWriter and StreamReader

I have been trying to organize a code that it is a mess! The first and my biggest problem at this point is that one of my StreamWriters or StreamReader is being left open. Using this link, I am trying to organize my code. But my problem is that I am not sure where should I close it:
My code is:
public static void ProcessFile(string[] ProcessFile, int id_customer, string directoryinprocess)
{
StreamWriter Writer = null, Writer2 = null, Writer3 = null;
foreach (string filename in ProcessFile)
{
// Used for the output name of the file
var dir = Path.GetDirectoryName(filename);
var fileName = Path.GetFileNameWithoutExtension(filename);
var ext = Path.GetExtension(filename);
var folderbefore = Path.GetFullPath(Path.Combine(dir, #"..\"));
int rowCount = 0;
string path_body_out = "";
string outputname = folderbefore + "output_temp\\" + fileName;
if (filename.Contains("RO_"))
{
Writer = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_hd_intermediate" + ext) { AutoFlush = true };
Writer2 = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_body_out" + ext) { AutoFlush = true };
path_body_out = dir + "\\" + "output_temp\\" + fileName + "_hd_intermediate" + ext;
} // end of if
else
{
Writer3 = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_out" + ext) { AutoFlush = true };
} // end of else
using (StreamReader Reader = new StreamReader(#filename))
{
while (!Reader.EndOfStream)
{
string inputLine = string.Empty;
inputLine = Reader.ReadLine();
rowCount++;
if (filename.Contains("RO_"))
{
if (rowCount <= 4)
{
Writer.WriteLine(inputLine);
}
if (rowCount >= 5)
{
Writer2.WriteLine(inputLine);
}
}
else
{
{ Writer3.WriteLine(inputLine); }
}
} // end of the while
} // end of using Stremreader
if (path_body_out.Contains("_hd_intermediate"))
{
ManipulateHeaderFilesTypeRo(dir, path_body_out);
}
else
{ }
} // end of the foreach
string[] extensions = { "_fv", "_body", "_out" };
string[] fileEntriesout = System.IO.Directory.EnumerateFiles(directoryinprocess, "*.csv", System.IO.SearchOption.AllDirectories)
.Where(file => extensions.Any(ex => Path.GetFileNameWithoutExtension(file).EndsWith(ex)))
.ToArray();
foreach (string filenameout in fileEntriesout)
{
string destinytablename = null;
if (filenameout.Contains("_hd_intermediate_fv"))
{ destinytablename = "TBL_DATA_TYPE_RO_HEADER"; }
else if (filenameout.Contains("_body_out"))
{ destinytablename = "TBL_DATA_TYPE_RO_BODY"; }
else
{ destinytablename = "TBL_DATA_TYPE_LOAD"; }
string id_file = Get_id_file(filenameout, id_customer);
DataTable csvFileData = GetDataTabletFromCSVFile(filenameout, id_file);
InsertDataIntoSQLServerUsingSQLBulkCopy(csvFileData, destinytablename);
} // end of the foreach
//} // end of the foreach
} // end of ProcessFile
Question:
How should I close the part:
if (filename.Contains("RO_"))
{
Writer = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_hd_intermediate" + ext) { AutoFlush = true };
Writer2 = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_body_out" + ext) { AutoFlush = true };
path_body_out = dir + "\\" + "output_temp\\" + fileName + "_hd_intermediate" + ext;
} // end of if
else
{
Writer3 = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_out" + ext) { AutoFlush = true };
} // end of else
using (StreamReader Reader = new StreamReader(#filename))
{
while (!Reader.EndOfStream)
{
string inputLine = string.Empty;
inputLine = Reader.ReadLine();
rowCount++;
if (filename.Contains("RO_"))
{
if (rowCount <= 4)
{
Writer.WriteLine(inputLine);
}
if (rowCount >= 5)
{
Writer2.WriteLine(inputLine);
}
}
else
{
{ Writer3.WriteLine(inputLine); }
Should I close here?
if (filename.Contains("RO_"))
{
Writer = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_hd_intermediate" + ext) { AutoFlush = true };
Writer2 = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_body_out" + ext) { AutoFlush = true };
path_body_out = dir + "\\" + "output_temp\\" + fileName + "_hd_intermediate" + ext;
} // end of if
else
{
Writer3 = new StreamWriter(dir + "\\" + "output_temp\\" + fileName + "_out" + ext) { AutoFlush = true };
} // end of else
Or here?
if (filename.Contains("RO_"))
{
if (rowCount <= 4)
{
Writer.WriteLine(inputLine);
}
if (rowCount >= 5)
{
Writer2.WriteLine(inputLine);
}
}
else
{
{ Writer3.WriteLine(inputLine); }
}

If you can't reorganize this code so that every StreamWriter instance can be wrapped in a using(), then perhaps you can do something like this:
StreamWriter Writer = null, Writer2 = null, Writer3 = null;
try
{
// your existing code
}
catch
{
// Handle
}
finally
{
if (Writer != null)
Writer.Close();
if (Writer2 != null)
Writer2.Close();
if (Writer3 != null)
Writer3.Close();
}
This ensures that no matter what error(s) happen within the try that your writers will be closed.
In my opinion, conditionally instantiating objects is a smell and you should work on having different implementations based on filename.Contains("RO_"). You could use the strategy pattern and have different file processor interface implementations, choosing the correct one based on the filename. Each implementation would only know how to write to the locations it needs. This would allow you to correctly use a using() around each writer.

Nomrally if you are using disposable objects, I would say use a using block. However, since you are conditionally instatiating disposable objects, I think the use of a try-finally block would be your best bet.
Declare disposable objects and intialize them to null outside of a try block.
Initialize the disposable objects to the instances you want inside of a try block. Take care not to change this reference anywhere inside of your try-block once you have created a disposable object.
Also inside of your try block, do everything you need to do with the disposable objects.
After your try block create a finally block (a catch block is optional, but you will need a finally block for this method to do its job.) and inside the finally block, check if the variables you declared to hold the disposable objects aren't null. and if they are not null, close them and make them null.
StreamWriter writer = null;
try {
if (condA) {
writer = new StreamWriter("filePath1");
} else if (condB) {
writer = new StreamWriter("filePath2");
} else {
writer = new StreamWriter("filePath3");
}
// do things with writer
} catch (Exception ex) {
} finally {
if (writer != null) {
writer.close();
writer = null;
}
}

Automatically create folders if does not exists in C#

So, I am trying to create a file at a specific path but the code I have doesn't allows me to create folders.
This is the code I have:
public void LogFiles()
{
string data = string.Format("LogCarga-{0:yyyy-MM-dd_hh-mm-ss}.txt", DateTime.Now);
for (int linhas = 0; linhas < dataGridView1.Rows.Count; linhas++)
{
if (dataGridView1.Rows[linhas].Cells[8].Value.ToString().Trim() != "M")
{
var pathWithEnv = #"%USERPROFILE%\AppData\Local\Cargas - Amostras\_logs\";
var filePath = Environment.ExpandEnvironmentVariables(pathWithEnv);
using (FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate))
{
using (StreamWriter writer = File.AppendText(filePath + data))
{
string carga = dataGridView1.Rows[linhas].Cells[0].Value.ToString();
string referencia = dataGridView1.Rows[linhas].Cells[1].Value.ToString();
string quantidade = dataGridView1.Rows[linhas].Cells[2].Value.ToString();
string dataemissao = dataGridView1.Rows[linhas].Cells[3].Value.ToString();
string linha = dataGridView1.Rows[linhas].Cells[4].Value.ToString();
string marca = dataGridView1.Rows[linhas].Cells[5].Value.ToString().Trim();
string descricaoweb = dataGridView1.Rows[linhas].Cells[6].Value.ToString().Trim();
string codprod = dataGridView1.Rows[linhas].Cells[7].Value.ToString().Trim();
string tipoemb = dataGridView1.Rows[linhas].Cells[8].Value.ToString().Trim();
string nomepc = System.Environment.MachineName;
writer.WriteLine(carga + ", " + referencia + ", " + quantidade + ", " + dataemissao + ", " + linha + ", " + marca + ", " + descricaoweb + ", " + codprod + ", "
+ tipoemb + ", " + nomepc);
}
}
}
}
}
This %USERPROFILE%\AppData\Local\ in the universal path and I want to automatically create the \Cargas - Amostras\_logs\.
Do you have any idea how to do it?

The simpelest solution is replace
using (FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate))
with
System.IO.Directory.CreateDirectory(filePath)
That will create the directory if it does not exist or do nothing if it does.

You need to create two checks, for your first folder and then second directory.
var pathWithEnv = #"%USERPROFILE%\AppData\Local\Cargas - Amostras\";
if (System.IO.Directory.Exists(pathWithEnv))
{
pathWithEnv = System.IO.Path.Combine(pathWithEnv, #"_logs\");
if (System.IO.Directory.Exists(pathWithEnv))
{
//Do what you want to do, both directories are found.
}
else
{
System.IO.Directory.CreateDirectory(pathWithEnv);
//Do what you want to do, both directories are available.
}
}
else
{
System.IO.Directory.CreateDirectory(pathWithEnv);
pathWithEnv = System.IO.Path.Combine(pathWithEnv, #"_logs\");
if (System.IO.Directory.Exists(pathWithEnv))
{
//Do what you want to do, both directories are available now.
}
else
{
System.IO.Directory.CreateDirectory(pathWithEnv);
//Do what you want to do, both directories are created.
}
}

Memory usage is growing while processing files

I'm developing an application that reads a xml file folder , and each file it to do some checks and copied to a new folder based on some criteria.
But memory usage continues to grow when it arrives in the foreach loop , and I believe that should not happen , because the variables do not increase at each iteration , are only overwritten.
Here is my code:
using System;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using System.Windows.Forms;
using System.Xml;
namespace XMLOrganizer
{
public partial class Form1 : Form
{
string selectedFolder;
public Form1()
{
InitializeComponent();
comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
comboBox1.SelectedIndex = 0;
}
private void button1_Click(object sender, EventArgs e)
{
folderBrowserDialog1.ShowDialog();
selectedFolder = folderBrowserDialog1.SelectedPath;
organizeBtn.Enabled = true;
}
private void organizeBtn_Click(object sender, EventArgs e)
{
if (comboBox1.SelectedIndex == -1)
{
MessageBox.Show("Selecione o tipo de nota", "Erro!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation,
MessageBoxDefaultButton.Button1);
return;
}
if (comboBox1.SelectedIndex != 2)
{
OrganizeXml(label2, selectedFolder, comboBox1);
}
//ORGANIZAR LOTES
else
{
string folder = selectedFolder;
label2.Text = "Arquivos sendo processados, aguarde...";
label2.Refresh();
string[] files = Directory.GetFiles(folder, "*.xml", SearchOption.AllDirectories);
int atualFile = 1, totalXML = files.Length;
foreach (string file in files)
{
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load(file);
XmlNodeList enviNFe = xmlDocument.GetElementsByTagName("enviNFe");
string versao = ((XmlElement)enviNFe[0]).Attributes["versao"].Value;
XmlNodeList NFe = ((XmlElement)enviNFe[0]).GetElementsByTagName("NFe");
Directory.CreateDirectory(selectedFolder + #"\NOTAS");
label2.Text = "Processando arquivo " + atualFile + " de " + totalXML;
string notaXML;
foreach (XmlElement nota in NFe)
{
notaXML = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><nfeProc versao=\"" + versao + "\" xmlns=\"http://www.portalfiscal.inf.br/nfe\">" + nota.OuterXml + "</nfeProc>";
XmlNodeList infNFe = nota.GetElementsByTagName("infNFe");
string chave = infNFe[0].Attributes["Id"].Value.Replace("NFe", "");
File.WriteAllText(selectedFolder + "\\NOTAS\\" + chave + ".xml", notaXML);
}
}
OrganizeXml(label2, selectedFolder + "\\NOTAS", comboBox1);
}
}
private static void OrganizeXml(Label label2, string selectedFolder, ComboBox comboBox1)
{
string folderMove = String.Empty;
string folder = selectedFolder;
label2.Text = "Arquivos sendo processados, aguarde...";
label2.Refresh();
string[] files = Directory.GetFiles(folder, "*.xml", SearchOption.AllDirectories);
int i = 1, arquivos = files.Length;
Directory.CreateDirectory(folder + #"\ORGANIZADO");
if (comboBox1.SelectedIndex != 2)
{
Directory.CreateDirectory(folder + #"\ORGANIZADO\OUTROS");
Directory.CreateDirectory(folder + #"\ORGANIZADO\LOTES");
}
foreach (string file in files)
{
XmlDocument xmlDocument = new XmlDocument();
try
{
xmlDocument.Load(file);
if (xmlDocument.DocumentElement.Name != "nfeProc")
{
XmlNodeList NFe = xmlDocument.GetElementsByTagName("NFe");
var nota = ((XmlElement) NFe[0]);
if (nota != null)
{
XmlNodeList infNFe = ((XmlElement) NFe[0]).GetElementsByTagName("infNFe");
string chave = infNFe[0].Attributes["Id"].Value.Replace("NFe", "");
string versao = infNFe[0].Attributes["versao"].Value;
string notaXML = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><nfeProc versao=\"" + versao +
"\" xmlns=\"http://www.portalfiscal.inf.br/nfe\">" + nota.OuterXml +
"</nfeProc>";
string dirNote = Path.GetDirectoryName(file);
File.WriteAllText(dirNote + "\\fix_" + chave + ".xml", notaXML);
}
}
//
//
//
}
catch (XmlException)
{
XmlDocument doc = new XmlDocument();
string arquivo = ReadFileToString(file);
arquivo = RemoveSpecialCharacters(arquivo);
if (arquivo == "")
{
File.Move(file, folder + #"\ORGANIZADO\OUTROS\corrupt_" + Path.GetFileName(file));
continue;
}
try
{
doc.LoadXml(arquivo);
doc.PreserveWhitespace = true;
doc.Save(file);
}
catch (XmlException)
{
File.Move(file, folder + #"\ORGANIZADO\OUTROS\corrupt_" + Path.GetFileName(file));
files = files.Where(f => f != file).ToArray();
}
}
}
foreach (string file in files)
{
string arquivoLoad = file;
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load(arquivoLoad);
XmlNodeList NFe = xmlDocument.GetElementsByTagName("NFe");
XmlNodeList enviNFe = xmlDocument.GetElementsByTagName("enviNFe");
if (NFe.Count == 0)
{
if (File.Exists(folder + #"\ORGANIZADO\OUTROS\no_NFe_" + Path.GetFileName(arquivoLoad)))
{
Random rnd = new Random();
File.Copy(arquivoLoad,
folder + #"\ORGANIZADO\OUTROS\no_NFe_" + rnd.Next(1, 5000) + Path.GetFileName(arquivoLoad));
}
else
{
File.Copy(arquivoLoad, folder + #"\ORGANIZADO\OUTROS\no_NFe_" + Path.GetFileName(arquivoLoad));
}
continue;
}
XmlNodeList infNFe = ((XmlElement)NFe[0]).GetElementsByTagName("infNFe");
string chave = infNFe[0].Attributes["Id"].Value.Replace("NFe", "");
if (xmlDocument.DocumentElement.Name != "nfeProc")
{
File.Move(arquivoLoad, folder + #"\ORGANIZADO\OUTROS\no_nfeProc_" + Path.GetFileName(arquivoLoad));
arquivoLoad = Path.GetDirectoryName(file) + "\\fix_" + chave + ".xml";
}
if (enviNFe.Count > 0)
{
if (File.Exists(folder + #"\ORGANIZADO\LOTES\" + Path.GetFileName(arquivoLoad)))
{
Random rnd = new Random();
File.Copy(arquivoLoad, folder + #"\ORGANIZADO\LOTES\" + rnd.Next(1, 5000) + Path.GetFileName(arquivoLoad));
}
else
{
File.Copy(arquivoLoad, folder + #"\ORGANIZADO\LOTES\" + Path.GetFileName(arquivoLoad));
}
continue;
}
//XmlNodeList infNFe = ((XmlElement)NFe[0]).GetElementsByTagName("infNFe");
XmlNodeList ide = ((XmlElement)infNFe[0]).GetElementsByTagName("ide");
string tpNF = ((XmlElement)ide[0]).GetElementsByTagName("tpNF")[0].InnerText;
//if (tpNF == "0") continue;
XmlNodeList emit = ((XmlElement)infNFe[0]).GetElementsByTagName("emit");
string emitInfoCod;
if (((XmlElement)emit[0]).GetElementsByTagName("CNPJ").Count > 0)
{
emitInfoCod = ((XmlElement)emit[0]).GetElementsByTagName("CNPJ")[0].InnerText;
}
else if (((XmlElement)emit[0]).GetElementsByTagName("CPF").Count > 0)
{
emitInfoCod = ((XmlElement)emit[0]).GetElementsByTagName("CPF")[0].InnerText;
}
else
{
emitInfoCod = "0";
}
string ide_dEmi = (((XmlElement)ide[0]).GetElementsByTagName("dEmi").Count > 0)
? ((XmlElement)ide[0]).GetElementsByTagName("dEmi")[0].InnerText
: ((XmlElement)ide[0]).GetElementsByTagName("dhEmi")[0].InnerText;
string[] data = ide_dEmi.Split('-');
string folderName = data[0] + "\\" + data[1];
string organizeStyle = String.Empty;
if (comboBox1.SelectedIndex == 0 || comboBox1.SelectedIndex == 2)
{
organizeStyle = folder + #"\ORGANIZADO\" + emitInfoCod + #"\" + folderName;
}
else
{
organizeStyle = folder + #"\ORGANIZADO\" + folderName + #"\" + emitInfoCod;
}
if (!Directory.Exists(organizeStyle))
{
Directory.CreateDirectory(organizeStyle);
}
folderMove = organizeStyle + "\\";
if (!File.Exists(folderMove + chave + ".xml"))
{
File.Copy(arquivoLoad, folderMove + chave + ".xml");
}
label2.Text = "Arquivos sendo processados, aguarde... (" + i + " / " + arquivos + ")";
label2.Refresh();
i++;
}
label2.Text = "Notas organizadas com sucesso!";
label2.Refresh();
}
public static string ReadFileToString(string filePath)
{
using (StreamReader streamReader = new StreamReader(filePath))
{
string text = streamReader.ReadToEnd();
streamReader.Close();
return text;
}
}
public static string RemoveSpecialCharacters(string str)
{
return Regex.Replace(str, #"[^\u0000-\u007F]", string.Empty);
}
private void exitBtn_Click(object sender, EventArgs e)
{
Application.Exit();
}
}
}
How can I determine what 's going on?

The value of a variable pointing to a reference type is not the object at all, its just the memory address where the object lives.
So when you do the following:
while (true)
{
var myVariable = new MyReferenceType();
}
The only memory you are really reusing is the variable itself (think of a 32 or 64 bit pointer). But on every iteration your are allocating somewhere in memory space enough to fit the new object you've just created and that memory is most definitely not the memory reserved to the previous object.
This is essentially why your memory usage is growing. The "old" objects of previous iterations with no live reference will eventually get collected by the GC, but that could be never if the GC decides that it has enough memory available to avoid it.

Confusion in Combining 4 Functions

please bear with me if my codes are messy or bulky, I am a real beginner which started programming a month ago with no background at all. I now have 4 functions created searchComByAuthor();, searchComByStartDate();, searchComByEndDate(); and searchComByKeywords();. But the problem is, I don't know how to combine them and make them like filters. User can choose to fill up any textboxes and when the user clicks on "Analyse" button, the combined function will do the work. Now they are all working separately, I only call the functions one by one to test out if they work or not.
Screenshot:
searchComByAuthor:
private void searchComByAuthor()
{
// Process the list of files found in the directory.
string[] fileEntries = Directory.GetFiles(sourceDir);
foreach (string fileName in fileEntries)
{
try
{
XmlDocument xmlDoc = new XmlDocument(); //* create an xml document object.
string docPath = fileName;
xmlDoc.Load(docPath); //* load the XML document from the specified file.
XmlNodeList nodeList = xmlDoc.GetElementsByTagName("item");
foreach (XmlNode node in nodeList)
{
XmlElement itemElement = (XmlElement)node;
string itemAuthor = itemElement.GetElementsByTagName("author")[0].InnerText;
if (itemAuthor.ToLower() == txtComAuthor.Text.ToString().ToLower())
{
string itemTitle = itemElement.GetElementsByTagName("title")[0].InnerText;
string itemDate = itemElement.GetElementsByTagName("pubDate")[0].InnerText;
string itemDescription = itemElement.GetElementsByTagName("description")[0].InnerText;
string itemXMLFile = Path.GetFileNameWithoutExtension(fileName);
richComByTemplate.AppendText("SYMBOL: " + itemXMLFile + "\nAUTHOR: " + itemAuthor + "\nDATE: " + itemDate +
"\nTITLE: " + itemTitle + "\nDESCRIPTION: " + itemDescription + "\n\n--------\n\n");
}
//else
//{
// richComResults.AppendText("There is no author " + txtComAuthor.Text.ToString().ToLower() + ". Please ensure you are using a correct author name.");
//}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
int pointer = 0;
int index = 0;
string keyword = txtComAuthor.Text;
string shadow = richComByTemplate.Text.ToLower();
while (true)
{
//Searching in the copy/shadow
index = shadow.IndexOf(keyword, pointer);
//if keyword not found then the loop will break
if ((index == -1) || (String.IsNullOrEmpty(keyword)))
{
break;
}
richComByTemplate.Select(index, keyword.Length);
richComByTemplate.SelectionColor = Color.Red;
richComByTemplate.SelectionFont = new System.Drawing.Font(richComByTemplate.Font, FontStyle.Bold);
pointer = index + keyword.Length;
}
}
searchComByStartDate:
private void searchComByStartDate()
{
// Process the list of files found in the directory.
string[] fileEntries = Directory.GetFiles(sourceDir);
foreach (string fileName in fileEntries)
{
XmlDocument xmlDoc = new XmlDocument(); //* create an xml document object.
string docPath = fileName;
xmlDoc.Load(docPath); //* load the XML document from the specified file.
XmlNodeList nodeList = xmlDoc.GetElementsByTagName("item");
foreach (XmlNode node in nodeList)
{
XmlElement itemElement = (XmlElement)node;
string itemDate = itemElement.GetElementsByTagName("pubDate")[0].InnerText;
CultureInfo provider = CultureInfo.InvariantCulture;
if (DateTime.Parse(itemDate) >= DateTime.ParseExact(txtComStartDate.Text, "dd/MM/yy", provider))
{
string itemAuthor = itemElement.GetElementsByTagName("author")[0].InnerText;
string itemTitle = itemElement.GetElementsByTagName("title")[0].InnerText;
string itemDescription = itemElement.GetElementsByTagName("description")[0].InnerText;
string itemXMLFile = Path.GetFileNameWithoutExtension(fileName);
richComByTemplate.AppendText("SYMBOL: " + itemXMLFile + "\nAUTHOR: " + itemAuthor + "\nDATE: " + itemDate +
"\nTITLE: " + itemTitle + "\nDESCRIPTION: " + itemDescription + "\n\n--------\n\n");
}
}
}
}
searchComByEndDate:
private void searchComByEndDate()
{
// Process the list of files found in the directory.
string[] fileEntries = Directory.GetFiles(sourceDir);
foreach (string fileName in fileEntries)
{
XmlDocument xmlDoc = new XmlDocument(); //* create an xml document object.
string docPath = fileName;
xmlDoc.Load(docPath); //* load the XML document from the specified file.
XmlNodeList nodeList = xmlDoc.GetElementsByTagName("item");
foreach (XmlNode node in nodeList)
{
XmlElement itemElement = (XmlElement)node;
string itemDate = itemElement.GetElementsByTagName("pubDate")[0].InnerText;
CultureInfo provider = CultureInfo.InvariantCulture;
if (DateTime.Parse(itemDate) <= DateTime.ParseExact(txtComEndDate.Text, "dd/MM/yy", provider))
{
string itemAuthor = itemElement.GetElementsByTagName("author")[0].InnerText;
string itemTitle = itemElement.GetElementsByTagName("title")[0].InnerText;
string itemDescription = itemElement.GetElementsByTagName("description")[0].InnerText;
string itemXMLFile = Path.GetFileNameWithoutExtension(fileName);
richComByTemplate.AppendText("SYMBOL: " + itemXMLFile + "\nAUTHOR: " + itemAuthor + "\nDATE: " + itemDate +
"\nTITLE: " + itemTitle + "\nDESCRIPTION: " + itemDescription + "\n\n--------\n\n");
}
}
}
}
searchComByKeywords:
private void searchComByKeywords()
{
List<TextBox> boxes = new List<TextBox>();
boxes.Add(txtComKeyword1);
boxes.Add(txtComKeyword2);
boxes.Add(txtComKeyword3);
boxes.Add(txtComKeyword4);
// Process the list of files found in the directory.
string[] fileEntries = Directory.GetFiles(sourceDir);
foreach (string fileName in fileEntries)
{
try
{
XmlDocument xmlDoc = new XmlDocument(); //* create an xml document object.
string docPath = fileName;
xmlDoc.Load(docPath); //* load the XML document from the specified file.
XmlNodeList nodeList = xmlDoc.GetElementsByTagName("item");
foreach (XmlNode node in nodeList)
{
XmlElement itemElement = (XmlElement)node;
string itemDescription = itemElement.GetElementsByTagName("description")[0].InnerText;
if (txtComKeyword1.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword1.Text.ToLower()) ||
txtComKeyword2.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword2.Text.ToLower()) ||
txtComKeyword3.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword3.Text.ToLower()) ||
txtComKeyword4.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword4.Text.ToLower()))
{
string itemTitle = itemElement.GetElementsByTagName("title")[0].InnerText;
string itemDate = itemElement.GetElementsByTagName("pubDate")[0].InnerText;
string itemAuthor = itemElement.GetElementsByTagName("author")[0].InnerText;
string itemXMLFile = Path.GetFileNameWithoutExtension(fileName);
richComByTemplate.AppendText("SYMBOL: " + itemXMLFile + "\nAUTHOR: " + itemAuthor + "\nDATE: " + itemDate +
"\nTITLE: " + itemTitle + "\nDESCRIPTION: " + itemDescription + "\n\n--------\n\n");
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
foreach (TextBox box in boxes)
{
int pointer = 0;
int index = 0;
string keyword = box.Text;
string shadow = richComByTemplate.Text.ToLower();
while (true)
{
//Searching in the copy/shadow
index = shadow.IndexOf(keyword, pointer);
//if keyword not found then the loop will break
if ((index == -1) || (String.IsNullOrEmpty(keyword)))
{
break;
}
//Customising the original data
richComByTemplate.Select(index, keyword.Length);
richComByTemplate.SelectionColor = Color.Red;
richComByTemplate.SelectionFont = new System.Drawing.Font(richComByTemplate.Font, FontStyle.Bold);
pointer = index + keyword.Length;
}
}
}

You have a very significant amount of repeated code in your functions.
You can achieve your goal while simplifying your code by combining your four functions into a single function. Give that single function a parameter that is a list of conditions that must be met in order to include a given record (assuming all conditions must apply to select the record).
In your case it looks like you desire a straight match on whatever is entered in one or more text fields. Pass in the values of those text fields to your new, combined method (so that you can separate your logic from your UI) and, for each value that has a non-null, non-blank value, apply the appropriate logic test. If Author and StartDate are passed in, apply the logic that is relevant to both Author and StartDate. If both tests pass, include that record.
In order to "include that record", rather than doing what the code is currently doing:
richComByTemplate.AppendText(...)
you may wish to return a list of results and have the caller do the text appending (again, to separate your user interface from your search logic).