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Search for word in ListBox written on InputBox (C# VS)

I have a ListBox with words and I need to click a button that opens an InputBox where I can search for a word and the program will run the ListBox and highlight the word I wrote in the InputBox if it's there. If the program reaches the end of the list and doesn't find the word then I'll get a MessageBox saying the word I'm looking for isn't there. I need to use some sort of cycle for this program.
I know how to make the button, InputBox and the error MessageBox, but I don't know how to do the searching and cycle.
I've read a lot of similar questions here but I don't think any of them return the result I'm looking for.
Can anyone help me? Or redirect me to a post with the answer?
This is for Winforms.

That should get you on track, it's pretty much self-explanative:
whenever text changes
find matching items in list
select them
Code:
private void textBox1_TextChanged(object sender, EventArgs e)
{
var textBox = sender as TextBox ?? throw new InvalidOperationException();
var text = textBox.Text;
if (string.IsNullOrWhiteSpace(text))
return; // nothing to search for
const StringComparison comparison = StringComparison.InvariantCultureIgnoreCase; // maybe change this
// find items matching text
var indices = new List<int>();
for (var i = 0; i < listBox1.Items.Count; i++)
{
var item = listBox1.Items[i];
if (string.Equals(item?.ToString(), text, comparison))
indices.Add(i);
}
// select them in list
if (!indices.Any())
return;
listBox1.SelectedIndices.Clear();
foreach (var index in indices)
listBox1.SelectedIndices.Add(index);
}
Of course, list selection mode has to be multiple for it to work properly.
Also, you will need to clear selection if there are no matches so as to not leave the UI in an ambiguous state (not done).

Multiple lines not reading into one list item

For some reason when I read in clipboard data and write it to a file, read that file in and set it to a list after delineating it with ¢ it loads up my listbox just fine on the first load as in when my form first loads up. However I have the following trigger on a button click, it is for some reason splitting up multiple line sections into separate list items, which is not what I want and not what the same code does when the form first loads. It's a little frustrating as it's writing to the text file and everything the same way.
private void button2_Click_1(object sender, EventArgs e)
{
// until next comment this is the same as what I have run at the start of the
// program, it loads up multiple lines into one list item as it should
string checkForDupe = File.ReadAllText(#"C:\temp\testfile.txt");
string checkResponses = File.ReadAllText(#"C:\temp\testfile2.txt");
if (Clipboard.ContainsText() && !checkForDupe.Contains(Clipboard.GetText()))
{
if (!checkResponses.Contains(Clipboard.GetText()))
{
var text = "\n" + Clipboard.GetText() + "¢";
File.AppendAllText(#"C:\temp\testfile.txt", text);
}
}
//The following has no affect on the issue stated in my question I have tried with out it.
string[] responseTags2 = File.ReadAllLines(#"C:\temp\testfile.txt");
List<string> _responseTags2 = new List<string>(responseTags2);
var count = _responseTags2.Count;
// Perform a reverse tracking.
for (var i = count - 1; i > -1; i--)
{
if (_responseTags2[i] == string.Empty) _responseTags2.RemoveAt(i);
}
// Keep only the unique list items.
_responseTags2 = _responseTags2.Distinct().ToList();
listBox1.BeginUpdate();
listBox1.DataSource = _responseTags2;
listBox1.EndUpdate();
}
input example:
"This is multiple lines in
a text file that is for testing
this application"
right output example (what I get when the same code is running at the start of the program before the form is loaded):
"This is multiple lines in
a text file that is for testing
this application" ,
"This is ANOTHER multiple lines in
a text file that is for testing
this application" ,
"This is a single line"
WRONG output (what I get when I run off the button click that eventual updates the UI):
"This is multiple lines in",
"a text file that is for testing",
"this application"

You are getting multiple lines in your listbox because you are not breaking the text by ¢ but just reading them into lines. This is your code:
string[] responseTags2 = File.ReadAllLines(#"C:\temp\testfile.txt");
Do this instead. Read all the text:
var contents = File.ReadAllText(#"C:\temp\testfile.txt");
Now split them using the character ¢:
var lines = s.Split('¢');
Here is the final linq to remove any empties and return distinct items:
var lines = s.Split('¢')
.Where(item => item != string.Empty)
.Distinct()
.ToList();
Then set lines to be the datasource:
listBox1.BeginUpdate();
listBox1.DataSource = lines;
listBox1.EndUpdate();

This code works fine for me, but I think it's basically what you're doing, only slightly cleaned up (and I didn't use the second file since you're not using it in the example).
My suggestion would be to create a single method that does this operation, and then call that method from wherever you need it. This way you will ensure that you're doing the exact same thing in both (all) places.
UPDATE
I updated the method to save the clipboard text as-is, plus adding a ¢ character to the end, when saving to the file. Then, when reading the file the second time, first join all the lines with a space character, then split on the ¢ character, and use that list for your data source.
private const string DefaultSaveFile = #"C:\temp\testfile.txt";
private void CopyUniqueClipboardTextToFile(string filePath = null,
bool updateListbox = true)
{
// Use global default file if nothing was passed
if (filePath == null) filePath = DefaultSaveFile;
// Ensure our files exist
if (!File.Exists(filePath)) File.CreateText(filePath).Close();
string fileContents = File.ReadAllText(filePath);
string clipboardText = Clipboard.GetText();
// Update the file with any new clipboard text
if (Clipboard.ContainsText() && !fileContents.Contains(clipboardText))
{
// Save the lines to our file, with a '¢' character at the end
File.AppendAllText(filePath, $"{Environment.NewLine}{clipboardText}¢");
}
// Re-read the new file into a single string
string entireFileAsOneLine = string.Join(" ",
File.ReadAllLines(filePath).Distinct().ToList());
// Now split that string on the '¢' character
string[] listItems = entireFileAsOneLine.Split('¢');
// Update listbox if necessary
if (updateListbox)
{
listBox1.BeginUpdate();
listBox1.DataSource = listItems;
listBox1.EndUpdate();
}
}
private void button2_Click(object sender, EventArgs e)
{
CopyUniqueClipboardTextToFile();
}

What I ended up doing is the following;
string responseTags2 = checkForDupe.Replace('\n', '╜');
I replaced new lines with a rarely used character, then split by ¢ to fill the list.
To replace the special character so that it would be formatted correctly again I just replaced it when setting the clipboard text with the \n again.

< character in RichTextBox causing issues

EDIT - Sorry folks, i guess i wanted to "obscure" my work code too much... i don't know why it got so many downvotes but anyway. see below for update/edit with actual code.
I am trying to insert a piece of text into an existing section of a line (<data) which resides at the beginning of a line in my RichTextBox control. However, whenever i do that in the following manner:
private void AddSelectedIntellisense(object sender, EventArgs e)
{
ToolStripItem x = sender as ToolStripItem;
int cursorpos = this.txt_Body.SelectionStart;
string final = this.txt_Body.Text.Insert(cursorpos, x.Text);
//final var at breakpoint is equal to "<data log=\"Original\""
//then i assign it/that to the RTB.Text
this.txt_Body.Text = final;
//when checked with breakpoint, this.txt_Body.Text is equal to
//"log=\"\"<data log=\"Original\""
this.txt_Body.SelectionStart = cursorpos + x.Text.Length;
}
I am thinking that it is the < character that is causing issues when i assign the string to the .Text property (because if i replace the < with a [ in my logic, no problems), but i don't know how to fix it... if you could help me i would really appreciate it.
I also checked all of the indexes manually and they all lign up perfectly... so i don't know why the RTB.Text value is different than the string but if someone knows please tell me.
Cheers!

You are first setting:
txt = this.RTB1.Text.Substring(starts, length);
Then on the next line you are replacing the value of txt:
txt = this.RTB1.Text.Insert(index,"log='test'></data>");
You are probably looking to concatenate the strings:
string txt = this.RTB1.Text.Substring(starts, length);
txt += this.RTB1.Text.Insert(index,"log='test'></data>");
this.RTB1.Text = txt;

Ok folks... i suppose i'll give it to Aaron, since it's like somewhat related and nobody else answered.
The answer was:
I am using the RTB.On_TextChanged event to fire off the intellisense based on a condition. However, because i am also setting text the RTB.Text value within the Intellisense, the condition became true twice and added the specific text twice. So i setup a flag when i add intellisense text and check it in the on_textchanged event.
Cheers and sorry for the confusion.

c# - Is there A Faster Way to Highlighting Regex Matches (RichTextBox)

I use RichTextBox for testing REGEX expression, with the code like:
rtbMain.SelectAll();
rtbMain.SelectionColor = Color.Black;
rtbMain.SelectionBackColor = Color.White;
Regex regex = new Regex(txtRegexPattern.Text, regexOptions);
Match matches = regex.Match(txtTest.Text);
while (matches.Success)
{
rtbMain.Select(matches.Index, match.Length);
rtbMain.SelectionColor = Color.Red;
rtbMain.SelectionBackColor = Color.Black;
}
But this method becomes too slow as soon as there are more than a few thousand (1000+) characters to be highlighted. I know I could delay processing, so that code gives user a chance to enter the whole Regular Expression, but still I think RichTextBox highlighting is working too slow.
I've searched the Google for different approaches and ways to speed up current solution, but I didn't have luck. I noticed that there are a few text editors which allow "syntax highlighting" (like ScintillNET, Avalon,...) but they use XML as input, so I think using them for my project (generating XML on every KeyUp event) wouldn't be the "best practice".
I have found and tested a "Fast colored Textbox" here: https://github.com/PavelTorgashov/FastColoredTextBox ...but the problem with this one is that it replaces the paste content while it uses its own new-line and tab character, and I cant use it in REGEX tester.
Is there any faster way to highlight all matches, maybe using a different user control?
EDIT:
APPROACH 1: Would generating the underlying RTF document be faster? I tried but had some problems with special characters, so I could test highlighting of the whole document, but it seemed to work quite fast with normal characters in a single line. I paused working on this since I read constructing RTF's can be quite hard, and I think I couldn't use none of the existing RTF libraries.
APPROACH 2: I am able to get only the displayed portion of RichTextBox, so I was thinking to only highlight that part. I guess this would significantly reduce processing (depends on RTB size), but I would need to trigger highlighting every time user scrolls; I'm not sure this would work well and create a decent user experience, so haven't tried it out yet.
Would anyone recommend any of the approaches above or maybe any others?

First:
The RichTextBox has an inherent problem: It is very slow in .NET. I found a solution how to make it 120 times faster. May be you try it out: C# RichEditBox has extremely slow performance (4 minutes loading) SOLVED
Second:
Building the RTF code from the scratch is far the fastest solution. Have a look a my article on codeproject. There is a RTF builder class that is reusable: http://www.codeproject.com/Articles/23513/SQL-Editor-for-Database-Developers

Please check Expresso at http://www.codeproject.com/Articles/3669/Expresso-A-Tool-for-Building-and-Testing-Regular-E
I have been using this program for editing and evaluating regex for years.

I have a doubt that you have setup your While loop in an incorrect manner.
Try something like this: (Untested, but will give you an idea how to troubleshoot this problem)
rtbMain.SelectAll();
rtbMain.SelectionColor = Color.Black;
rtbMain.SelectionBackColor = Color.White;
Regex regex = new Regex(txtRegexPattern.Text, regexOptions);
MatchCollection matches = regex.Matches(txtTest.Text);
if(matches.Count > 0)
{
foreach(Match m in matches)
{
rtbMain.Select(m.Index, m.Length);
rtbMain.SelectionColor = Color.Red;
rtbMain.SelectionBackColor = Color.Black;
}
}
else
{
Debug.Print("No matches found"); // See "Output" Window
}
EDIT
I did some workaround related to highlight RTF text and first thing I found is the mostly time taken by the process was these lines:
rtbMain.SelectionColor = Color.Red;
rtbMain.SelectionBackColor = Color.Black;
I tried selecting the text using SelectionStart and SelectionEnd properties instead .Select(), but NO change has been observed.
Regarding your first point which is related to constructing equivalent RTF, I tried that too but it is difficult to construct an equivalent RTF since there are lot of stuff there which needs to be handle. If it can be done the process time will be around < 1.5 seconds for more than 31k matches (a result of basic test on a specific sample).
So, I would suggest you to do it via THREADING and split task in two threads:
Here is an example source code:
(For worst case i found around 31341 matches and process took 4 seconds to highlight)
// declare variables either globally or in the same method
MatchCollection mcoll;
Stopwatch s;
int callbackCount = 0;
List<Match> m1 = null;
List<Match> m2 = null;
private void btnHighlight_Click(object sender, EventArgs e)
{
//reset any exisiting formatting
rtbMain.SelectAll();
rtbMain.SelectionBackColor = Color.White;
rtbMain.SelectionColor = Color.Black;
rtbMain.DeselectAll();
s = new Stopwatch();
s.Start();
Regex re = new Regex(#"(.)", RegexOptions.Compiled); // Notice COMPILED option
mcoll = re.Matches(rtbMain.Text);
// Break MatchCollection object into List<Matches> which is exactly half in size
m1 = new List<Match>(mcoll.Count / 2);
m2 = new List<Match>(mcoll.Count / 2);
for (int k = 0; k < mcoll.Count; k++)
{
if (k < mcoll.Count / 2)
m1.Add(mcoll[k]);
else
m2.Add(mcoll[k]);
}
Thread backgroundThread1 = new Thread(new ThreadStart(() => {
match1(null, null);
}));
backgroundThread1.Start();
Thread backgroundThread2 = new Thread(new ThreadStart(() =>
{
match2(null, null);
}));
backgroundThread2.Start();
}
public void match1(object obj, EventArgs e)
{
for (int i=0; i < m1.Count; i += 1)
{
if (rtbMain.InvokeRequired)
{
EventHandler d = new EventHandler(match1);
rtbMain.Invoke(d);
}
else
{
rtbMain.Select(m1[i].Index, m1[i].Length);
rtbMain.SelectionBackColor = Color.Black;
rtbMain.SelectionColor = Color.Red;
}
}
stopTimer();
}
public void match2(object obj, EventArgs e)
{
for (int j=0; j < m2.Count; j += 1)
{
if (rtbMain.InvokeRequired)
{
EventHandler d = new EventHandler(match2);
rtbMain.Invoke(d);
}
else
{
rtbMain.Select(m2[j].Index, m2[j].Length);
rtbMain.SelectionBackColor = Color.Black;
rtbMain.SelectionColor = Color.Red;
}
}
stopTimer();
}
void stopTimer()
{
callbackCount++;
if (callbackCount == 2) // 2 because I am using two threads.
{
s.Stop();
// Check Output Window
Debug.Print("Evaluated in : " + s.Elapsed.Seconds.ToString());
}
}
Since as you posted it takes around 30 sec to manipulate, hope 4 sec is bearable and user can be engaged by some loading screen as the other online converters do like Rubular and DerekSlager's .Net regex tester does.
Don't forget to have a look at Why Regex.Compiled preferred.

Multi-line textbox shows mult-line string as One-Line

I am making a program where you enter an item's name and it's description. Then you add it to a listbox and after you are done you can save all the items to a 'txt' file. (Using StreamWriter). This program also has an edit button that allows you to edit the description in the listbox by removing it first from the listbox and then showing it back in the textbox (, so you can edit it)
If the description is multi-line, it will successfuly show it multi-line when I select it in the listbox and click the edit button that will show it back in the textbox. BUT if I save all the items in the listbox to a file first. And then open up the file again so it load the items back into the listbox. And then clicking the edit button...
The multi-line description will show as a one-line description in the textbox.
I am not sure why - but I've also made a label that will show the exact string that the textbox is suppose to show and the label is showing it multi-lined while textbox isn't!
The string is definitely multi-line but the multi-line textbox is showing it one-line after loading the items back into the listbox using StreamReader.
Example of the multi-line string: (named "theString1")
This is line 1
This is line 2
Using the following code: TextBox1.Text = theString1; this appears in the text box:
This is line1This is line2
But if I use the same code with a label. It will show it correctly.
If someone can explain to me why this is happening I will be more than happy. I just need an explanation.
Thanks in advance.
---[More info]---
Just so you know. I came up with this code myself so it is probably set-up all wrong.
I will be happy if you tell me a better way to do this.
I am using a list to store the description text + the item name. I seperated these two using '`' .And splited the string (see code).
This is the code that happens when you click the edit button. It removes the item from
the listbox and shows it in the textbox so you can edit it and add to listbox again:
int index = listBox.SelectedIndex;
itemName.Text = listBox.SelectedItem.ToString();
var descVar = descList.ElementAt(index).Split('`');
string theString1 = descVar[1];
TextBox1.Text = theString1;
This is how it saves it to a file:
FileDialog save = new SaveFileDialog();
save.Title = "Save information...";
save.DefaultExt = "Text File|*.txt";
save.Filter = "Text File|*.txt";
if (save.ShowDialog() == DialogResult.OK)
{
StreamWriter sw = new StreamWriter(save.FileName);
foreach (string s in listBox.Items) //This writes the names of item names.
{
sw.WriteLine(s);
}
sw.WriteLine("`1`"); //I use this to seperate the item names from description.
foreach (string s in descList) //This writes the descriptions that are stored in a list named "descList".
{
sw.WriteLine(s);
sw.WriteLine("``"); //I use this to seperate descriptions from each other because they are multi-line.
}
sw.WriteLine("`2`"); //Just something so I know where it ends. :D
sw.Close();
}
else
{
}
And this is how it loads: (This can definitely be better!)
FileDialog load = new OpenFileDialog();
load.Title = "Load information...";
load.DefaultExt = "Text File|*.txt";
load.Filter = "Text File|*.txt";
if (load.ShowDialog() == DialogResult.OK)
{
List<string> loadDesc = new List<string>(); //Don't ask you will see why
descList.Clear();
while (listBox.Items.Count > 0) //This removes all items in the listbox to load new ones.
{
int index = 0;
listBox.Items.RemoveAt(index);
descList.Clear();
itemName.Text = "";
}
StreamReader rw = new StreamReader(load.FileName);
for (; true; )
{
string read = rw.ReadLine();
if (read == "`1`") //When it reaches the separator I made it stops reading.
{
break;
}
else
{
listBox.Items.Add(read);
}
}
for (; true; )
{
string read = rw.ReadLine();
if (read == "`2`")
{
break;
}
else
{
loadDesc.Clear();
loadDesc.Add(read);
for (; true; ) //Please tell me if this can be done differently.
{
string read2 = rw.ReadLine();
if (read2 != "``") //This will keep reading the whole description until it reaches the separator.
{
loadDesc.Add(read2); //Adds each line into the list I created.
}
else
{
break;
}
}
string oneBigString = string.Join("\n", loadDesc); //This basically converts all strings in a list into one string.
descList.Add(oneBigString); //And this finally add the string to the main list from where it then loads.
}
}
}
else
{
}
I believe that is it.
If there is anything else you need - tell me.

string oneBigString = string.Join("\n", loadDesc); is where the issue is.
Use Environment.NewLine instead of \n
I'm also just going to go over a couple of things that could be improved with your code (there are a lot, but I just want to cover a couple).
while (listBox.Items.Count > 0) //This removes all items in the listbox to load new ones.
You don't need to iterate over every element in the listbox to remove it. You can just do listBox.clear()
Also, using break to get out of loops is generally bad practice. This should be written as...
for (; true; )
{
string read = rw.ReadLine();
if (read == "`1`") //When it reaches the separator I made it stops reading.
{
break;
}
else
{
listBox.Items.Add(read);
}
}
this
string read = rw.ReadLine()
while(read != "`1`")
{
listBox.Items.Add(read);
read = rw.ReadLine()
}
but theres more, what if 1 is never found in the file? It would crash your program, so you also need to check if there is more data to be read...
string read = rw.ReadLine()
while(read != "`1`" && !sw.EndOfStream) // Make sure you're not at the end of the file
{
listBox.Items.Add(read);
read = rw.ReadLine()
}