ListView formatting when reading from text file - c#

I'm trying to read data from a text file and populate that data in a listview. However, when I read the data in and then add it to the listview, it is trying to put everything on the same line just in different columns. I would like it to read each line of the txt file and put each line in its own row in the listview. Can anyone help me out with this? Not much experience using listviews, or reading from text files for that matter.
Thanks for any help.
string path = #"..\..\blah.txt";
StreamReader textIn = new StreamReader(new FileStream(path, FileMode.Open, FileAccess.Read));
while (textIn.Peek() != -1)
{
string str = textIn.ReadLine();
listviewOptions.Items.Add(str);
}
textIn.Close();

You can use the code below to read and populate your listview in one go:
listviewOptions.Items.AddRange(File.ReadLines(#"..\..\blah.txt").ToArray());
It uses File.ReadLines method to read lines from your file and List.Items.AddRange to add them all.

Related

Prepend headers to my c# excel output file

I have this block of code and want to insert headers before it writes. I have tried various ways but it keeps reading and mixing the headers with the data being written to file. I tried adding the heading outside the if block but it still makes no difference, I also tried adding it right after the file is created but same result. I would like to know how to add it without it mixing with the data
using (StreamWriter stream = new StreamWriter("cross_check.xls", true))
{
if (stream == null)
{
MessageBox.Show("File can't be written");
}
else
{
stream.WriteLine();
stream.Write(search.Text);
stream.Write("\t ");
stream.Write(textBox1.Text);
MessageBox.Show("Data Added Successfully");
}
You can include the header when you write data to file. But if you have some existing files which need modification and if the content of your excel file is text contents (which seems to be, based on the question), you can simply use File.ReadAllLines and File.WriteAllLines this way:
var file = #"d:\file.xls";
var lines = System.IO.File.ReadAllLines(file).ToList();
lines.Insert(0, "Some text");
System.IO.File.WriteAllLines(file, lines);
Using File.ReadAllLines you have all lines of your file and you can perform additional processing on file contents too. For example you can split all lines by a delimiter and manipulate each cell or add new columns and so on. Also you can shape the result into a data structure like DataTable and show it in DataGridView to edit them and save them back to the file again.

c# - Reading lines from text file and adding to listbox

I think my question is simple. I've searched but not found a solution for the method that I'm actually using.
I save the content of a listbox into a text file with success, but I'm having problem on load.
For create the file, I use:
using(StreamWriter file = File.CreateText(path))
To write the content from the listbox to file, I use:
foreach (string content in listDOF.Items)
{
file.WriteLine(content);
}
This works very well.
Now, I just need load the saved content with succes.
I've tried:
if (File.Exists(filesrc))
{
File.OpenRead(filesrc);
string[] line = System.IO.File.ReadAllLines(filesrc);
listDOF.Items.Add(line);
}
But this does not work and give me an exception.
How to do this correctily? Thanks all in advance! :)
You are adding an array of strings. The method to use is AddRange
string[] lines = System.IO.File.ReadAllLines(filesrc);
listDOF.Items.AddRange(lines);
The File.OpenRead is not needed. You could remove that line

Append to RTF file in C#

Is there a way to append content to a RTF file format?
I need it for the following functionality. When adding a Paragraph to the FlowDocument, I need to write it to the RTF file, also. Till now I was saving the entire FlowDocument into the file. In addition, I don't want to keep the more than 10000 Paragraphs in memory.
Here is a piece of code I tried but it didn't work.
TextRange tr = new TextRange(flowDoc.ContentStart, flowDoc.ContentEnd);
FileStream file = new FileStream(path, FileMode.Append,FileAccess.ReadWrite, FileShare.Read);
tr.Save(file, DataFormats.Rtf);
TextWriter tw = new StreamWriter(file);
tw.Write(file.ToString());
tw.Close();
Thanks!
The only thing I could think of is to use a temp RichTextBox. Copy and paste into it all the formatted text you want to append, and then copy and paste from it. You will need another temp Richtextbox to convert from rtf code to formatted text before copying and pasting to the other one.

C# - Read in a large (150MB) text file into a Rich Text Box

I'm trying to read in a 150mb text file into a Rich Text box.
Currently, I am using a StreamReader to iterate through each line in the file, appending every line to a StringBuilder instance.
This works for smaller files, but I get a System.OutOfMemory exception when trying to read large files.
I don't see any problems with reading a 150mb file - there is plenty of physical memory and that's well within the Windows 32-bit application address space.
If anyone here has any idea how to do this, It would be greatly appreciated.
I'll attach my code at the end.
Thanks.
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(fileLocation))
{
string line;
while ((line = sr.ReadLine()) != null)
{
sb.AppendLine(line);
}
}
return sb;
Use RichTextBox.LoadFile
http://msdn.microsoft.com/en-us/library/system.windows.forms.richtextbox.loadfile.aspx
I'm not sure why you would want to load the entire text to a StringBuilder. Alternatively you could pass a FileStream to LoadFile which would render the large file for you.
I guess you should manage somehow the input file - let say split it into several less files and navigate between the parts programmatically or so..
150MB file sounds like an abnormal thing. Maybe you should look at the stream kind of data processing rather than file one.

How to paste CSV data to Windows Clipboard with C#

What I'm trying to accomplish
My app generates some tabular data
I want the user to be able to launch Excel and click "paste" to place the data as cells in Excel
Windows accepts a format called "CommaSeparatedValue" that is used with it's APIs so this seems possible
Putting raw text on the clipboard works, but trying to use this format does not
NOTE: I can correctly retrieve CSV data from the clipboard, my problem is about pasting CSV data to the clipboard.
What I have tried that isn't working
Clipboard.SetText()
System.Windows.Forms.Clipboard.SetText(
"1,2,3,4\n5,6,7,8",
System.Windows.Forms.TextDataFormat.CommaSeparatedValue
);
Clipboard.SetData()
System.Windows.Forms.Clipboard.SetData(
System.Windows.Forms.DataFormats.CommaSeparatedValue,
"1,2,3,4\n5,6,7,8",
);
In both cases something is placed on the clipboard, but when pasted into Excel it shows up as one cell of garbarge text: "–§žý;pC¦yVk²ˆû"
Update 1: Workaround using SetText()
As BFree's answer shows SetText with TextDataFormat serves as a workaround
System.Windows.Forms.Clipboard.SetText(
"1\t2\t3\t4\n5\t6\t7\t8",
System.Windows.Forms.TextDataFormat.Text
);
I have tried this and confirm that now pasting into Excel and Word works correctly. In each case it pastes as a table with cells instead of plaintext.
Still curious why CommaSeparatedValue is not working.
The .NET Framework places DataFormats.CommaSeparatedValue on the clipboard as Unicode text. But as mentioned at http://www.syncfusion.com/faq/windowsforms/faq_c98c.aspx#q899q, Excel expects CSV data to be a UTF-8 memory stream (it is difficult to say whether .NET or Excel is at fault for the incompatibility).
The solution I've come up with in my own application is to place two versions of the tabular data on the clipboard simultaneously as tab-delimited text and as a CSV memory stream. This allows the destination application to acquire the data in its preferred format. Notepad and Excel prefer the tab-delimited text, but you can force Excel to grab the CSV data via the Paste Special... command for testing purposes.
Here is some example code (note that WinForms-equivalents from the WPF namespaces are used here):
// Generate both tab-delimited and CSV strings.
string tabbedText = //...
string csvText = //...
// Create the container object that will hold both versions of the data.
var dataObject = new System.Windows.DataObject();
// Add tab-delimited text to the container object as is.
dataObject.SetText(tabbedText);
// Convert the CSV text to a UTF-8 byte stream before adding it to the container object.
var bytes = System.Text.Encoding.UTF8.GetBytes(csvText);
var stream = new System.IO.MemoryStream(bytes);
dataObject.SetData(System.Windows.DataFormats.CommaSeparatedValue, stream);
// Copy the container object to the clipboard.
System.Windows.Clipboard.SetDataObject(dataObject, true);
Use tabs instead of commas. ie:
Clipboard.SetText("1\t2\t3\t4\t3\t2\t3\t4", TextDataFormat.Text);
Just tested this myself, and it worked for me.
I have had success pasting into Excel using \t (see BFree's answer) as column separators and \n as row separators.
I got the most success defeating formatting issues by using a CSV library (KBCsv) to write the data into a CSV file in the temp folder then open it in Excel with Process.Start(). Once it is in Excel the formatting bit is easy(er), copy-paste from there.
string filePath = System.IO.Path.GetTempPath() + Guid.NewGuid().ToString() + ".csv";
using (var streamWriter = new StreamWriter(filePath))
using (CsvWriter csvWriter = new CsvWriter(streamWriter))
{
// optional header
csvWriter.WriteRecord(new List<string>(){"Heading1", "Heading2", "YouGetTheIdea" });
csvWriter.ValueSeparator = ',';
foreach (var thing in YourListOfThings ?? new List<OfThings>())
{
if (thing != null)
{
List<string> csvLine = new List<string>
{
thing.Property1, thing.Property2, thing.YouGetTheIdea
};
csvWriter.WriteRecord(csvLine);
}
}
}
Process.Start(filePath);
BYO Error handing & logging.

Categories

Resources