Displaying log file in a multiline textbox - c#

I'm writing data to a log file and need to display that data in my WinForms UI. My initial thought was to use a multiline textbox like this:
private void UpdateUITextbox(string text)
{
textBoxStatus.AppendText(text + Environment.NewLine);
}
I don't write a huge amount of text to my log file but over time, it's going to add up and I'll probably end up exceeding whatever the default maxlength for a multiline textbox is. The only thing I can think of to do to prevent this from happening is to hook into the OnKeyPress event handler and check the length of the textbox before I add something to it and, when necessary, to remove the older text to make room for the newer text. But this seems like it would definitely have an impact on performance. Someone please tell me that there is a better way to do this?

A Winforms TextBox has a maximum length of 2GB.
You'll have to worry about usability long before you worry about memory issues - if the log is too long, your users are not going to be able to use it effectively.

We show our log using AvalonEdit. It scales very well up to hundreds of thousands of lines.

Instead of a multi-line text box why don't you use a list box ?
And for the log, its best to add more information to your logs while saving them such as the time.
And on the load read each line which has a date stamp in the range you think is fairly recent.
It is not wise to to load all of your log files just at once. load only the new ones.
If you need to see the older logs,You can still manage that using the time/date stamp solution.

Related

C# textbox endline

What I'm trying to do is insert, from a text box, into a MS Access database some text (no surprises). Thing is that after submitting what I have written, when I open the Access database it all appears as one string of text. So my question: is there a way in which I can determine the end of the text box per line so that when it reaches that point it would make a new line? Or something similar so that it would introduce a new line into the database file because this issue is very annoying.
P.S.: Yes the multiline option is enabled.
Thank you very much.
I believe you are trying to solve a non-problem. Quite possibly you'll find that you will want to show the same text in a number of different places within your application or even different applications (if it's not true now it MIGHT be true at some point in the future), so it should the the GUI to decide where and when break a text line, not your DB
You could either detect Environment.NewLine within the textbox's text, or you could use the Lines property to access each line individually.

Retain values in dialog box after closing - windows forms c#

I'm relatively new to C# and Windows forms so excuse me for what may seem like an easy question.
I have a windows application which has a dialog box which when opened contains textboxes with some default values. These can be changed depending on what the user wants to use. The values in this dialog box together with the content on the main form are then used to create an XML file. The issue I have is if I go to open the dialog box again to change any values in the same session, the original values are there and not any of the new values.
How do I get it to keep the values that have been changed in that particular session?
If you want to see the user's values the next time you open the dialog box, you'll need to save those values somewhere, and then re-load them the next time the dialog is displayed (usually on Form_Load or Form_Show). And of course you'll need to save the values (probably in Form_Close?) before exiting.
Where you save those values is up to you. You can save them in some static variables in the form class if you want it to be just for that run of the program. Or you can store in a configuration file, the registry, isolated storage, etc. if you want to re-load those settings the next time the program is run.
If I'm understanding the question correctly it sounds like you need to make use of background variables and TextChanged events (although I prefer KeyDown events and my code uses that instead). For instance, let's call your textbox TextBox1. You can then make a global variable called string Temp and use it like this:
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
temp = textBox1.Text;
}
Once your dialog box is closed you can use that variable elsewhere, in your case it sounds like you want to send it to an XML.
Another option is to use the keydown event to have a temporary XML file that retains the value of your text. This is obviously more computationally expensive but it's not really that big of a deal unless this is going to be used in a processor limited environment.
The last thing I'd mention is that you may run into trouble if you're using multi-threading and passing the value of that temp value. Look into using variables on other threads than you started with for help with that.
If you want to keep the values the user entered the last time he used your dialog, you need to keep a reference to your dialog somewhere.
Also if you set some data in your dialog on the Load event it might erase the data previously entered by the user. Without seeing your code I can't tell more at this point.

Text user control with sorting possibility

I need control in winforms that can add tens lines per second. I use now richtextbox, but i'm looking for something with sorting possibility (according some datatime or int)
Lines which are added are just custom objects complex of several int and datetime.
Delay aspect is quite important here.
EDIT:
It can be also some table/grid, but I suppose it take too much time (searching existing lines and inserting new line into appropriate place)
RichTextBox will typically offer more overhead in managing, searching, and inserting.
Much more appropriate would be a control like ListView. It gives simpler control over sorting, scrolling, and more.
Additionally, ListView has the ability to handle Virtual data backing. If performance or content size is an issue, this will let you only worry about the sub-set currently displayed in the ListView "view" window.
Two options
Use RichTextBox as you are doing now hold the data in a structure like SortedList from which the control will be updated.
Or, you can use a Grid, format the look and feel of the grid to remove the row & column grid lines and each new line will get appended this way you can let user sort by clicking on the header...
As for adding say ten lines per second I am pretty certain both these controls can handle more traffic than that....

TextBox Text Management

I have a WPF application where I'm trying to create a "diagnostics panel" that's very similar to the "Output Window" in Visual Studio 2010. It simply contains a text box where all types of output are collected and appended in the text box using the .AppendText() method.
We have a couple of customers who leave this diagnostics panel up all the time and never clear it. As a result, a very large amount of text gets displayed as new output continues to come in...
The WPF TextBox has a MaxLength property which I leave set to 0. According to the MSDN documentation, "When this property is set to 0, the maximum length of the text that can be entered in the control is limited only by available memory."
For the customers that leave this panel up, I hate to just let the text and memory grow uncontrolled... I think this may eventually cause the application to hang up...
I am curious if there's a good way to mange this... I want to keep a certain number of lines displayed in the text box and discard the oldest as new lines come in...
Any thoughts?
Thanks!
Why not use a listbox with each sentence getting its own textblock - so you can get virtualization?
http://social.msdn.microsoft.com/Forums/en/wpf/thread/98090161-0abf-4799-bbcb-852dcc0f0608
You could have a DispatcherTimer in your code behind. With this you, you can set it to Tick every 10 minutes (or whatever time period you want). And in the Tick event handler method, you can take the text in your textbox, throw away the all but the amount of text you want to save and then set the that text back to the textbox.
You could also save the text to a log text file. You'd have to figure out what to append to the text file so you won't write the same text to it multiple times. This depends on what exactly your needs are.
DispatcherTimer documenation
Like Xaisoft said, you shouldn't use a TextBox for this, probably a TextBlock instead. You might have to put that inside a ScrollViewer, I don't remember.
Here's how you handle it:
Write the log info to a text file
Write the log info to your text box (although I don't like textboxes, it should be okay.)
When writing to the text box, only display the last maybe 20 or so (play with this) lines. Everything else should "roll off"
If your users really want to save everything, no biggie, it already is saved to that file.
Upon each execution of the app, or at some appropriate interval, roll your logging to a new file.

RichTextbox MaxLength too small

I need to open a text file with ~4MB in a RichTextBox, but the end of the text was "trimmed".
How do I override a RichTextBox.MaxLength Int32 limit?
I'm not sure how much text RichTextBox can handle, but I believe MaxLength only applies to text the user enters. If you set .Text directly it should be able to go past MaxLength, unless MaxLength is already at the maximum.
The default for RichTextBox.MaxLength is 2GB, so with a 4MB file this is not going to be your problem.
Besides that, you can set the text limit(max limit is limited by your memory) by setting its length, something like:
if (textToAdd.Length > richTextBox1.MaxLength)
...it doesn't sound good loading that much amount of data in the box; you may run into out of memory hiccups!
This answer may help.
--EDIT--
Must, if you load, then you can load chunks from the file. And as user clicks the scroll button(up/down) load that chunk of the file; sounds like some code - but Must, if you load! Just thinking!
OK the max size of the RichTextBox is 2,147,483,647 that is a lot of typing, if you are thinking copy past it may better to read in the data as opposed to copying to a RichTextBox.

Categories