We Keep Coding

c# richtextbox display character remaining count

Yes, I have already researched this question. I've found this: How to display remaining textbox characters in a label in C#? and many others just like it. That's how I managed to get this following code pieced together:
protected void rtdDisclaimer(object sender, EventArgs e)
{
lblCharCount.Text = "Characters Remaining:" + (700 - rtbDisclaimer.Text.Length).ToString(); // char count limit set to 700
}
I've never coded in c# before, but am working on a group project and that's the language the group lead chose. I'm new to programming and have minimal experience with java. This program is being done in visual studio. I'm trying to make the label show the number of characters remaining depending upon what's typed in the richtextbox. There are no errors, but the label isn't displaying anything at all.

You must associate the method to the textchanged event of the control.
protected void rtbDisclaimerTextChanged(object sender, EventArgs e)
{
lblCharCount.Text = "Characters Remaining:" + (700 - rtbDisclaimer.Text.Length).ToString(); // char count limit set to 700
}
On the constructor, after InitializeComponent(), yo must add this line:
rtbDisclaimer.TextChanged += new EventHandler(rtbDisclaimerTextChanged);

Your code will work, but you need to attach the method to the correct event on your RichTextBox, so it will invoke that code when the event fires.
Add this to the constructor of your Form:
rtbDisclaimer.TextChanged += rtdDisclaimer;

The function you mentioned in your question seems a server side and you can call it on a an event like a button's click.
If you want to display characters length while typing then use JavaScript/jQuery
like
$('textarea').keyup(updateCount);
$('textarea').keydown(updateCount);
function updateCount() {
var cs = $(this).val().length;
$('#characters').text(cs);
}
Check this too. JsFiddle example (by Dreami)
Hepe this helps!

Second TextBox showing same Text Selection as first

Long time listener, first time caller here. I'm having a strange issue with the TextBox in WinRT C#/XAML that I hope someone may be able to help me with.
Basically, I'm working on creating a Custom Control that essentially requires a second TextBox to be a copy of the first, including showing the same Text, and showing the same Selected Text. Obviously for the Text requirement I simply respond to the TextChanged event on the first TextBox and set the Text of the second TextBox to the Text from the first, which works great.
For the Selected Text requirement I started with a similar solution, and my code for this is as follows:
void TextBox1_SelectionChanged(object sender, RoutedEventArgs e)
{
this.TextBox2.Select(this.TextBox1.SelectionStart, this.TextBox1.SelectionLength);
}
This seemed to work pretty well when initially used with a mouse:
But I'm having a problem when selecting text with Touch. I double-tap within the TextBox to create the first "anchor" as you do in Touch, then drag to begin the selection; but I only ever manage to select a single character normally before the selection stops. The TextBox doesn't lose focus exactly, but the behaviour is similar to that; the selection anchors disappear and I can't continue selecting anything unless I re-double-tap to start a new selection. If I remove the code to select text in TextBox2 then the Touch selection behaves perfectly in TextBox1.
I've been trying to fix this for a while and cannot, I'm not sure if I can get the desired behaviour with WinRT TextBoxes. Does anyone have any ideas? Or perhaps another way to implement a solution with two TextBoxes with this behaviour?
Thanks a lot.

So this is far from an answer, but discovered a few things that maybe will help you or others come up with a potential workaround. Apologies if these are things you've already seen and noted.
First, it's not the call to TextBox2.Select() that's the problem per se. This for instance, works fine for me
private void txt1_SelectionChanged(object sender, RoutedEventArgs e)
{
var start = TextBox1.SelectionStart;
var length = TextBox1.SelectionLength;
TextBox2.Select(3, 5);
}
unfortunately, using start and length versus the hard-coded 3 and 5, that is, the following, DOES NOT WORK:
private void txt1_SelectionChanged(object sender, RoutedEventArgs e)
{
var start = TextBox1.SelectionStart;
var length = TextBox1.SelectionLength;
TextBox2.Select(start, length);
}
I also discovered that I could select TWO characters if I started from the end, but only one from the beginning. That got me to thinking about dispatching the call to set the second selection:
private void txt1_SelectionChanged(object sender, RoutedEventArgs e)
{
var start = TextBox1.SelectionStart;
var length = TextBox1.SelectionLength;
Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Low,
() => TextBox2.Select(start, length));
}
Now I can select 2 from the front and 3 and sometimes 4 from the back. Took it a step further, and was able to select as many as six or seven with a really fast swipe.
private void txt1_SelectionChanged(object sender, RoutedEventArgs e)
{
var start = TextBox1.SelectionStart;
var length = TextBox1.SelectionLength;
Dispatcher.RunIdleAsync((v) => Highlight());
}
public void Highlight()
{
TextBox2.Select(TextBox1.SelectionStart, TextBox1.SelectionLength);
}
Seems like the trick to working around this is not setting TextBox2 until whatever vestiges of the TextBox1 SelectionChanged event have completed.
This may be worth registering on Connect.

Mine is only a partial solution as well.
I did some debugging and noticed that the SelectionChanged event is fired throughout the text selection process. In other words, a single finger "swipe" will generate multiple SelectionChanged events.
As you found out, calling TextBox.Select during a text selection gesture affects the gesture itself. Windows seems to stop the gesture after the programmatic text selection.
My workaround is to delay as long as possible calling the TextBox.Select method. This does work well, except for one edge case. Where this method fails is in the following scenario:
The user begins a select gesture, say selecting x characters. The user, without taking their finger off the screen, pauses for a second or two. The user then attempts to select more characters.
My solution does not handle the last bit in the above paragraph. The touch selection after the pause does not actually select anything because my code will have called the TextBox.Select method.
Here is the actual code. As I mentioned above, there are multiple selection changed events fired during a single selection gesture. My code uses a timer along with a counter to only do the programmatic selection when there are no longer any pending touch generated selection changed events.
int _selectCounter = 0;
const int SELECT_TIMER_LENGTH = 500;
async private void TextBox1_SelectionChanged(object sender, RoutedEventArgs e)
{
// _selectCounter is the number of selection changed events that have fired.
// If you are really paranoid, you will want to make sure that if
// _selectCounter reaches MAX_INT, that you reset it to zero.
int mySelectCount = ++_selectCounter;
// start the timer and wait for it to finish
await Task.Delay(SELECT_TIMER_LENGTH);
// If equal (mySelectCount == _selectCounter),
// this means that NO select change events have fired
// during the delay call above. We only do the
// programmatic selection when this is the case.
// Feel free to adjust SELECT_TIMER_LENGTH to suit your needs.
if (mySelectCount == _selectCounter)
{
this.TextBox2.Select(this.TextBox1.SelectionStart, this.TextBox1.SelectionLength);
}
}

How to get a textbox to only display Uppercase letters?

Using Windows Mobile 6.5 and C#
The CharacterCasing property seems to be missing from WinMo 6.5 and I decide to just catch the textchanged event and set the text with ToUpper.
This works - but on every keypress, it sends the cursor back to the beginning of the string, not the end.

I know this is old, but hopefully this can help somebody else. I implemented the KeyPress event like the following.
private void TextBox_KeyPress(object sender, KeyPressEventArgs e)
{
e.KeyChar = Char.ToUpper(e.KeyChar);
}

Ritu, just to comment on your answer. You should keep in mind that this might be confusing for a user if the user has positioned the caret in the middle of the string to perform some edit and then the caret jumps to the end of the string on the key press.
An alternative might be to change the text to upper case when the edit control loses focus.

Try here such implementation.
public MainForm()
{
InitializeComponent();
InitializeUpperCaseTextBox();
}
private void InitializeUpperCaseTextBox()
{
txtbox.CharacterCasing = CharacterCasing.Upper;
//... etc.
}

The soluttion of setting the text position to the end of the string seems like would be a hassle if you ever need to edit text that you have already entered.
It's been a while since I thought about the C# event model but, one alternative might be to catch the KeyPress event and change any lowercase KeyChar values to uppercase before passing them on to the next handler.

The way you are approaching seems to be wrong.
There are so many different ways to insert data into that textbox. What about copy & paste for instance?
Just perform a .Text.ToUpper() when accessing the value of the Textbox

Save the SelectionStart and SelectionLength before changing the text. The ToUpper should make no changes to the length, so you can simply set the SelctionStart and SelectionLength back to what they had been.
Also, I would expect to get a changed event again when you set it ToUpper. I'm not sure if you also need to check that the ToUpper actually changed anything before you set Text again. It may be smart enough to check that for you when you assign the text and avoiding giving you an infinite recursive loop of change events. However, you probably don't want to alter the selection in the event handler call for the case where you aren't making a further change, only in the outer call where you are assigning back to Text. So you might as well guard recursion directly.
Something like:
bool m_InMyTextChanged = false;
private void txtMyText_TextChanged(object sender, EventArgs e)
{
if (m_InMyTextChanged)
return; // Recursive! We can bail quickly.
m_InMyTextChanged = true; // Prevent recursion when we change it.
int selectionStart = txtMyText.SelectionStart;
int selectionLength = txtMyText.SelectionLength;
string originalText = txtMyText.Text;
string newText = originalText.ToUpper();
if (newText != originalText)
{
txtMyText.Text = newText; // Will cause a new TextChanged event.
// Set the selection back *after* the assignment, which has reset them.
txtMyText.SelectionStart = selectionStart;
txtMyText.SelectionLength = selectionLength;
}
m_InMyTextChanged = false; // Allow it for next time.
}
could work. I haven't worked in Windows Mobile, but I would think this would work the same as in general for .NET.

I figured it out. So on the textChanged event, I replace the entered text with the ToUpper version. Then I set the SelectionStart property to the Text.Length to move the cursor to the end.

CheckedListBox populating a text control

I have a text box that is going to be populated with a comma spereated list that is driven by a CheckedListBox control.
The idea is that as the user checks items off in the list, they will appear in the text field above. I have this working to the point where if I check an item and then click somewhere else inside the control then the text ends up in the textbox. I am capturing the click event on my control.
If I use the item_checked event then the list in the text box isn't updated until I check a second item (at which point in time only the first item that was checked is displayed in the text box.) Is there anyway around this? Reading on MSDN doesn't seem to show any other events that would be applicable.
I'm using .net 1.1.
This is the method that is run on the event trap.
Private Sub FillCheckedTagsTextBox()
txtSelectedTags.Text = ""
Dim tagChecked As Object
For Each tagChecked In cltTagSelection.CheckedItems
txtSelectedTags.Text = txtSelectedTags.Text + tagChecked.ToString() + ", "
Next
End Sub
Thanks,
Mike

Ouch 1.1? Is your employer trying to kill you? I'd try to push up to 2.0 if I could.
To double check when you say the "Checked" event do you mean CheckedChanged? In 2.00 this works fine on desktop. Is it a bug in 1.1?
If it is a bug (check your own code first before deciding this! Then check it again!) then I can suggest trying to capture the Leave event which occurs when a control loses focus. Failing this you could databind a business object to the .Checked property and then fire your own event when your value changes. E.G.
public class MyValues
{
private bool _check;
public bool Check
{
get
{
return _check;
}
set
{
if(_check != value)
{
_check = value;
// todo: raise event!
}
}
}
}

How to detect previous state of text field in C#?

I'm coding a simple text editor using Windows Forms. As in many editors, when the text changes the title bar displays an asterisk next to the title, showing that there is unsaved work. When the user saves, this goes away.
However, there is a problem. This is handled in the change event of the main text box. But this gets called too when a file is opened or the user selects "New file", so that if you open the editor and then open a file, the program says that there are unsaved changes. What is a possible solution?
I thought of having a global variable that says whether the text changed in a way that shouldn't trigger the asterisk, but there has to be a better way.

before loading data to a textbox, unassociate first the eventhandler for change
uxName.TextChanged -= uxName_TextChanged;
uxName.Text = File.ReadAllText("something.txt");
uxName.TextChanged += uxName_TextChanged;

This is a horrible solution, but every time the text change event fires, compare the value of the textbox to some variable, and if they are different store the contents on the textbox in a variable and add the asterisk. When the method is invoked via the New File dialog or any other such event that is NOT changing the text, the asterisk won't appear.
This is not a viable solution for a real text editor since the memory would quickly get out of hand on even medium-sized files. Using a finger tree or whatever data structure text editors use to compare "versions" of the text is the only real efficient solution, but the premise is the same.
http://scienceblogs.com/goodmath/2009/05/finally_finger_trees.php
Below the second picture he mentions the use of finger trees in text editors to implement an extremely cheap "undo" feature, but I'm sure you can see the validity of the tree for your problem as well.

There are no global variables in C#. You should have such an variable as an instance variable in your form (or better yet, in a model for which your form is a view), and that is perfectly fine.

This is a very simple and stupid solution. I would use a MVP design pattern for this but here the fastest and simple solution:
//Declare a flag to block the processing of your event
private bool isEventBlocked = false;
private void OnTextChanged(object sender, EventArgs e)
{
if(!isEventBlocked)
{
//do your stuff
}
}
private void OnNewFile() //OR OnOpenFile()
{
try
{
isEventBlocked = true;
CreateFile();
}
catch
{
//manage exception
}
finally
{
isEventBlocked = false;
}
}