im trying to make a code that searches through a textfile for a certain phrase and then populates a textbox with the line if a phrase occurs in that. There are no errors with this code, but it doesn't work at all. Anyone know what is wrong? I'm not too sure if what i'm doing is remotely correct.
{
tuitDisplayTextBox.Text = "";
string[] tuitFilePath = File.ReadAllLines(Server.MapPath("~") +"/App_Data/tuitterMessages.txt");
for (int i = 0; i < tuitFilePath.Length; i++)
{
if (tuitFilePath[i].Contains(searchTextBox.Text))
{
tuitDisplayTextBox.Text += tuitFilePath[i];
}
}
Your solution should work... for the last line that matches, and only that one.
LINQ can help you here, though. Here's a solution that should work.
tuitDisplayTextBox.Text =
File.ReadLines(Server.MapPath("~") +"/App_Data/tuitterMessages.txt")
.Where(n => n.Contains(searchTextBox.Text)).Aggregate((a, b) =>
a + Enviroment.NewLine + b);
Here, what it does is it reads the lines of the file into an IEnumerable<string>, and then I filter that with the Where method, which basically means "if the condition is true for this element, add this element to the list of things to return, else don't add it". And then Aggregate is a bit more complicated. Basically what it does is it takes the first two items from the collection, and then pass a lambda through them that returns a value. Then call the lambda again with that result and the third element. And then it takes that result and calls it with the fourth element. And so on.
Here's some code more similar to yours that will also work:
tuitDisplayTextBox.Text = "";
IEnumerable<string> lines =
File.ReadAllLines(Server.MapPath("~") +"/App_Data/tuitterMessages.txt");
StringBuilder sb = new StringBuilder
foreach (string line in lines)
{
if (line.Contains(searchTextBox.Text))
{
sb.AppendLine(line);
}
}
tuitDisplayTextBox.Text = sb.ToString();
Here it's a bit different. First it reads all the lines into an IEnumerable<string> called lines. Then it makes a StringBuilder object (basically a mutable string). After that, it foreaches the lines in the IEnumerable<string> (I thought it was more appropriate here) and then if the line contains the text you want, it adds that line and a newline to the StringBuilder object. After that, it sets your textbox's text to the result of all of that, by getting the string representation of the StringBuilder instance.
And if you really want a for loop, here's the code modified to use a for loop:
tuitDisplayTextBox.Text = "";
string[] lines =
File.ReadAllLines(Server.MapPath("~") +"/App_Data/tuitterMessages.txt");
StringBuilder sb = new StringBuilder
for (int i = 0; i < lines.Length; i++)
{
if (lines[i].Contains(searchTextBox.Text))
{
sb.AppendLine(lines[i]);
}
}
tuitDisplayTextBox.Text = sb.ToString();
Please note that File.ReadAllLines break sentences at '\r' or '\n'.
So, if you search for "hello world" and this text is break in the file into 2 lines (e.g. "... hello /n world" your code will failed...
So, use the ReadAllText() instead, return one string contains all file's text.
Still, you might face sometimes problems with file encoding, but this is another issue.
After, and if, you find the text you are searching for you can use the ReadAllLines to decide about the location of the text.
Related
I am trying to make my program display the text above the input text which matches a pattern I set.
For example, if user input 'FastModeIdleImmediateCount"=dword:00000000', I should get the closest HKEY above, which is [HKEY_CURRENT_CONFIG\System\CurrentControlSet\Enum\SCSI\Disk&Ven_ATA&Prod_TOSHIBA_MQ01ABD0\4&6a0976b&0&000000] for this case.
[HKEY_CURRENT_CONFIG\System\CurrentControlSet\Enum\SCSI\Disk&Ven_ATA&Prod_TOSHIBA_MQ01ABD0\4&6a0976b&0&000000]
"StandardModeIdleImmediateCount"=dword:00000000
"FastModeIdleImmediateCount"=dword:00000000
[HKEY_CURRENT_CONFIG\System\CurrentControlSet\SERVICES]
[HKEY_CURRENT_CONFIG\System\CurrentControlSet\SERVICES\TSDDD]
[HKEY_CURRENT_CONFIG\System\CurrentControlSet\SERVICES\TSDDD\DEVICE0]
"Attach.ToDesktop"=dword:00000001
Could anyone please show me how I can code something like that? I tried playing around with regular expressions to match text with bracket, but I am not sure how to make it to only search for the text above my input.
I'm assuming your file is a .txt file, although it's most probably not. But the logic is the same.
It is not hard at all, a simple for() loop would do the trick.
Code with the needed description:
string[] lines = File.ReadAllLines(#"d:\test.txt");//replace your directory. We're getting all lines from a text file.
string inputToSearchFor = "\"FastModeIdleImmediateCount\"=dword:00000000"; //that's the string to search for
int indexOfMatchingLine = Array.FindIndex(lines, line => line == inputToSearchFor); //getting the index of the line, which equals the matchcode
string nearestHotKey = String.Empty;
for(int i = indexOfMatchingLine; i >=0; i--) //looping for lines above the matched one to find the hotkey
{
if(lines[i].IndexOf("[HKEY_") == 0) //if we find a line which begins with "[HKEY_" (that means it's a hotkey, right?)
{
nearestHotKey = lines[i]; //we get the line into our hotkey string
break; //breaking the loop
}
}
if(nearestHotKey != String.Empty) //we have actually found a hotkey, so our string is not empty
{
//add code...
}
You could try to split the text into lines, find the index of the line that contains your text (whether exact match or regex is used doesn't matter) and then backsearch for the first key. Reverse sorting the lines first might help.
How can I delete words from a "string" in the RichTextBox.
Example:
[02/04/2014 17:04:21] Thread 1 Banned: xxxxxxxxx#xxxx.tld
[02/04/2014 17:04:21] Thread 2: Banned: xxxxxxxxx#xxxx.tld
[02/04/2014 17:04:21] Thread 3: Banned: xxxxxxxxx#xxxx.tld
[02/04/2014 17:04:21] Thread 4: Banned: xxxxxxxxx#xxxx.tld
I would like to delete all rows with the word "Banned" in the line.
How can I do this?
Thanks in advance.
You can use LINQ to remove all the lines that contains the work "Banned":
richTextBox1.Lines = richTextBox1.Lines
.Where((line, b) => !line.Contains("Banned"))
.Select((line, b) => line).ToArray();
I know this method looks ugly. But, if you don't want to remove formatting from the existing text in the richtextbox then you should use this method. This example is not tested but, you can get logic from here.
for (int iLine = 0; iLine < rtf.Lines.Length; iLine++)
{
if (rtf.Lines[iLine].Contains("Banned"))
{
int iIndex = rtf.Text.IndexOf(rtf.Lines[iLine]);
rtf.SelectionStart = iIndex;
rtf.SelectionLength = rtf.Lines[iLine].Length;
rtf.SelectedText = string.Empty;
iLine--; //-- is beacause you are removing a line from the Lines array.
}
}
You could try use the answer from this post - I would adjust the code slightly to neaten it up a bit.
URL:
what is the best way to remove words from richtextbox?
Code snippet from the URL (which would need to be tidied up).
string[] lines = richTextBox1.Lines;
List<string> linesToAdd = new List<string>();
string filterString = "Banned".";
foreach (string s in lines)
{
string temp = s;
if (s.Contains(filterString))
temp = s.Replace(filterString, string.Empty);
linesToAdd.Add(temp);
}
richTextBox1.Lines = linesToAdd.ToArray();
I would adjust the above code and whilst still using the loop, just check if the line contains the word you looking for "Banned" and then remove the line / do what is need with it.
I hope this helps?
I am beginning to program in .Net and C# and currently I am stuck. I have a very similar problem as the posting on this question at stackoverflow : C#: Multiline TextBox with TextBox.WordWrap Displaying Long Base64 String.
The response to that question was this block of code:
public IEnumerable<string> SimpleWrap(string line, int length)
{
var s = line;
while (s.Length > length)
{
var result = s.Substring(0, length);
s = s.Substring(length);
yield return result;
}
yield return s;
}
I dont know how to make use of that piece of code. CAn someone please provide me with a code snippet that uses this particular method to write text that automatically also inserts a new line.
My code currently looks like this:
var length = GetMaximumCharacters(txtBxResults);
var txtWrap = SimpleWrap(stringValue, length);
foreach (string s in txtWrap)
{
txtBxResults.AppendText(s);
}
If I use AppendText method, it simple writes all the text in one single line which I do not want.
Any replies will be greatly appreciated.
Thanks,
KK
You almost have it right, you just need to insert the newline character as well. Try
foreach (string s in txtWrap)
{
txtBxResults.AppendText(s + Environment.NewLine);
}
Well I can't give you the exact code right now (I'll come back and post it later) but in general, what you should do is identify the index of the next comma and, if characters on the current line + that index > length of the line then append a new line before that compound. If you do that in a bucle, when it's done it should be formatted correctly, also take into account the last compound won't have (I think) a comma at the end.
I have a Stringbuilder object that has been populated from a text file.
How can I check the StringBuilder object for and remove consecutive "blank" lines.
i.e
Line 1: This is my text
Line 2:
Line 3: Another line after the 1st blank one
Line 4:
Line 5:
Line 6: Next line after 2 blank lines
(Line numbers given as reference only)
The blank line on Line 2 is fine, but I would like to remove the duplicate blank line, on Line 5, and so on.
If for argument sake Line 6 would have also been a blank line, and a Line 7 had a value, I would like Blank Line 5 and Blank Line 6 removed, so that there would only be 1 blank line between the Line 3 and Line 7.
Thanks in advance.
Do you have to already have the file contents in a StringBuilder?
It would be nicer to be able to read line-by-line. Something like:
private IEnumerable<string> GetLinesFromFile(string fileName)
{
using (var streamReader = new StreamReader(fileName))
{
string line = null;
bool previousLineWasBlank = false;
while ((line = streamReader.ReadLine()) != null)
{
if (!previousLineWasBlank && string.IsNullOrEmpty(line))
{
yield return line;
}
previousLineWasBlank = string.IsNullOrEmpty(line);
}
}
}
Now you can read in your text (which has had dupe blank lines removed) like this:
foreach (var line in GetLinesFromFile("myFile.txt"))
{
Console.WriteLine(line);
}
Note: I'm only illustrating a technique here. There are other considerations: e.g. my iterator method holds the file open while the consumers are processing the foreach. This is nice and memory efficient (more so than reading into a string for example) as you are only dealing with one line at a time, but not ideal for files that take a long time to process.
Probably not very efficient, but it's easy.
while(sb.ToString().Contains(Environment.NewLine + Environment.NewLine))
{
sb = sb.Replace(Environment.NewLine + Environment.NewLine, Environment.NewLine);
}
StringBuilder is a lot less flexible when it comes to searching & removing from. It's used as a helper to speed up concatenation as "string" + "another string" is a very costly operation.
I would suggest using .ToString() then Regex.Replace with a compiled regular expression with flags set to allow multiline.
You'll probably want a search pattern of:
(\n[\w-\n]*\n)
And you replace it with the empty string.
Check out Expresso for a great .NET Regular expression tool.
I have a block of text and I want to get its lines without losing the \r and \n at the end. Right now, I have the following (suboptimal code):
string[] lines = tbIn.Text.Split('\n')
.Select(t => t.Replace("\r", "\r\n")).ToArray();
So I'm wondering - is there a better way to do it?
Accepted answer
string[] lines = Regex.Split(tbIn.Text, #"(?<=\r\n)(?!$)");
The following seems to do the job:
string[] lines = Regex.Split(tbIn.Text, #"(?<=\r\n)(?!$)");
(?<=\r\n) uses 'positive lookbehind' to match after \r\n without consuming it.
(?!$) uses negative lookahead to prevent matching at the end of the input and so avoids a final line that is just an empty string.
Something along the lines of using this regular expression:
[^\n\r]*\r\n
Then use Regex.Matches().
The problem is you need Group(1) out of each match and create your string list from that. In Python you'd just use the map() function. Not sure the best way to do it in .NET, you take it from there ;-)
Dmitri, your solution is actually pretty compact and straightforward. The only thing more efficient would be to keep the string-splitting characters in the generated array, but the APIs simply don't allow for that. As a result, every solution will require iterating over the array and performing some kind of modification (which in C# means allocating new strings every time). I think the best you can hope for is to not re-create the array:
string[] lines = tbIn.Text.Split('\n');
for (int i = 0; i < lines.Length; ++i)
{
lines[i] = lines[i].Replace("\r", "\r\n");
}
... but as you can see that looks a lot more cumbersome! If performance matters, this may be a bit better. If it really matters, you should consider manually parsing the string by using IndexOf() to find the '\r's one at a time, and then create the array yourself. This is significantly more code, though, and probably not necessary.
One of the side effects of both your solution and this one is that you won't get a terminating "\r\n" on the last line if there wasn't one already there in the TextBox. Is this what you expect? What about blank lines... do you expect them to show up in 'lines'?
If you are just going to replace the newline (\n) then do something like this:
string[] lines = tbIn.Text.Split('\n')
.Select(t => t + "\r\n").ToArray();
Edit: Regex.Replace allows you to split on a string.
string[] lines = Regex.Split(tbIn.Text, "\r\n")
.Select(t => t + "\r\n").ToArray();
As always, extension method goodies :)
public static class StringExtensions
{
public static IEnumerable<string> SplitAndKeep(this string s, string seperator)
{
string[] obj = s.Split(new string[] { seperator }, StringSplitOptions.None);
for (int i = 0; i < obj.Length; i++)
{
string result = i == obj.Length - 1 ? obj[i] : obj[i] + seperator;
yield return result;
}
}
}
usage:
string text = "One,Two,Three,Four";
foreach (var s in text.SplitAndKeep(","))
{
Console.WriteLine(s);
}
Output:
One,
Two,
Three,
Four
You can achieve this with a regular expression. Here's an extension method with it:
public static string[] SplitAndKeepDelimiter(this string input, string delimiter)
{
MatchCollection matches = Regex.Matches(input, #"[^" + delimiter + "]+(" + delimiter + "|$)", RegexOptions.Multiline);
string[] result = new string[matches.Count];
for (int i = 0; i < matches.Count ; i++)
{
result[i] = matches[i].Value;
}
return result;
}
I'm not sure if this is a better solution. Yours is very compact and simple.