I have a TextBox where a user is meant to enter a product code that looks like this:
XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
What I'm trying to do is automatically placing the dashes in the right place as the user is typing, so that they only have to enter the actual code itself (similar to what's done in various pieces of software).
The problems I'm encountering have got to do with the position of the cursor as the user is typing.
My current solution (partially working) is as the following:
private void textBoxProductKey_KeyPress(object sender, KeyPressEventArgs e)
{
if (char.IsControl(e.KeyChar))
{
return;
}
if (!char.IsLetterOrDigit(e.KeyChar) || textBoxProductKey.Text.Length == 29)
{
e.Handled = true;
return;
}
var cursorPosition = textBoxProductKey.SelectionStart;
string text;
if (cursorPosition == 0)
{
text = e.KeyChar + textBoxProductKey.Text;
}
else if (cursorPosition == textBoxProductKey.Text.Length)
{
text = textBoxProductKey.Text + e.KeyChar;
}
else
{
text = textBoxProductKey.Text.Insert(cursorPosition, e.KeyChar.ToString());
}
text = Regex.Replace(text, "-", "");
text = Regex.Replace(text, ".{5}", "$0-");
textBoxProductKey.Text = text.Length <= 29 ? text : text.Substring(0, 29);
textBoxProductKey.SelectionStart = cursorPosition / 6 == (cursorPosition + 1) / 6
? cursorPosition + 1
: cursorPosition + 2;
e.Handled = true;
}
The two problems with my current solution are
It doesn't properly handle the delete/backspace keys where potentially the dashes need to be deleted/inserted in different locations and the cursor position re-calculated
It doesn't work properly if the cursorPosition == textBoxProductKey.Text.Length.
The latter is very easy to fix, but I'm struggling with the former and also feel like the code is a bit convoluted.
How can I more easily achieve this (note the plan is to continue using a TextBox object).
EDIT
I am aware of the MaskedTextBox control, I do not want to use a MaskedTextBox, I want to use a TextBox.
What I am trying to do is not outside the realms of possibility for a TextBox, even if there are "easier" ways to accomplish this with other controls.
Also I feel like this is a great question for teaching people how to work with the cursor in a TextBox (among other things probably).
Have you considered using the MaskedTextBox control? It might be more appropriate.
The MaskedTextBox is designed precisely for this type of requirement and would answer your original question.
You may find it more difficult to implement this functionality yourself with a normal TextBox. It's also worth weighing up which solution is more likely to be be bug-free and easier to maintain.
It may helpful if you could to explain to us why you would prefer use a TextBox over a MaskedTextBox.
Continuing our conversation, save your current caret position, parse the whole text as if it's new, and return the caret to its original position.
That way you handle deleting as well as copy-pasting
Related
i've noticed something within VS/C# thats a bit of a grey area for me? was hoping someone could explain. i've followed guides online to set up a Treeview Control, and copied and pasted the code that said it handled the label and put it through certain validations as you'll see below, however the desired result is not quite there.
What is happening:
it seems as though the code is only checking the edit, and not the label? because if the label isn't changed, i start to see the messageboxes come up even though, the value isn't null, the length is > 0 AND does NOT contain special characters.. which leads me to beleive its only checking the new value?
private void TreeSlabs_AfterLabelEdit(object sender, NodeLabelEditEventArgs e)
{
if (e.Label != null)
{
if (e.Label.Length > 0)
{
if (e.Label.IndexOfAny(new char[] { '#', '.', ',', '!' }) == -1)
{
// Stop editing without canceling the label change.
e.Node.EndEdit(false);
}
else
{
/* Cancel the label edit action, inform the user, and
place the node in edit mode again. */
e.CancelEdit = true;
MessageBox.Show("Invalid tree node label.\n" +
"The invalid characters are: '#','.', ',', '!'",
"Node Label Edit");
e.Node.BeginEdit();
}
}
}
else
{
/* Cancel the label edit action, inform the user, and
place the node in edit mode again. */
e.CancelEdit = true;
MessageBox.Show("Invalid tree node label.\nThe label cannot be blank",
"Node Label Edit");
e.Node.BeginEdit();
}
}
could someone verify my theory?
What would be the better way around this code to test the value? i know the values going into the tree are "validated" as per the conditions above.. so really if the label hasn't changed, it should still allow the edit but it wont...?
Any advice, as always greatly appreciated.
Many Thanks in advance to SO community.
Jack
I am making this sum creator where user will have to type an answer using custom keyboard. and on check button click if answer is correct then new question is loaded.
My problem is after answering first question answer button reset to blank but when user types next answer, only one last alphabet is deleted (for example 5 from 15). and when i type 14 it shows 114 (1 from previously typed answer).
I need help to reset answer button text to blank.
I am using buttons because later i want to add more questions at the same time so user will have multiple answers to click and type.
Can anyone please help me on this? Also tell me if this is the right method to achieve what i want.
I am calling backspace function to delete previous answer and also setting text to blank.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class Keyboard : MonoBehaviour
{
string word = null;
int wordIndex = -1;
string alpha = null;
string alpha2 = null;
public Text userAnswer1 = null;
public Text valueA, valueB;
public Text scoreCount;
private int a, b, answer1, score;
char[] nameChar = new char[5];
private void Start()
{
SumCreator();
}
public void nameFunc (string alphabet)
{
wordIndex++;
char[] keepchar = alphabet.ToCharArray();
nameChar[wordIndex] = keepchar[0];
alpha = nameChar[wordIndex].ToString();
word = word + alpha;
userAnswer1.text = word;
}
public void BackspaceFunction()
{
if (wordIndex >= 0)
{
wordIndex--;
alpha2 = null;
for (int i = 0; i < wordIndex + 1; i++)
{
alpha2 = alpha2 + nameChar[i].ToString();
}
word = alpha2;
userAnswer1.text = word;
}
}
public void SumCreator ()
{
a = Random.Range(0,15);
b = Random.Range(0,15);
answer1 = a + b;
valueA.text = a.ToString();
valueB.text = b.ToString();
scoreCount.text = "score " + score.ToString();
}
public void CheckAnswer()
{
Text buttonText = userAnswer1.GetComponentInChildren<Text>();
if (answer1 == int.Parse(userAnswer1.text))
{
score++;
// userAnswer1.text = string.Empty;
buttonText.text = string.Empty;
}
SumCreator();
}
}
I've edited my answer and removed the now irrelevant parts.
Once the button "Check" is clicked, first of all erase the text in the result textbox, then do the whole other logic.
To erase the text you can use next piece of code:
Text buttonText = buttonName.GetComponentInChildren<Text>();
buttonText.text = string.Empty;
You probably want to have this "buttonText" property as a global and get it once, at the start of the program instead of getting it every time the button is clicked. It won't do much difference in a small scale program, but it's a right way of thinking.
After checking your code a bit more, I can summarize your problem:
The whole logic of your program is flawed, there're many unnecessary complicated things which make it fail in several places. It is understandable, everybody goes through this stage, nothing to be ashamed or worried about. Either way it's my subjective opinion, which may be wrong.
Back to your code, all you have to do is update your result text, say "txtResult", once anything happens.
Once you click a number, do "txtResult += numberClicked".
Once you click backspace, remove last char of txtResult. Here is a question with many answers on how to do it, it's really simple.
Once you click "Check", in case it's the right number, set txtResult to empty.
Also, every time you update txtResult, you're supposed to update the UI too of course. Let's say you do it every time, it would be one line to update txtResult, and one line to update UI for each of the above 3 cases. So in total 6 lines. A check for an empty string while in "Backspace" function adds another line. My math could be wrong, but either way, it's quite short and simple approach, nothing too complicated.
You just lack relevant knowledge, otherwise you wouldn't be doing that nightmare in your Backspace function.
Regarding the "nameFunc" function, the whole 6 lines could be replaced with "txtResult += alphabet", isn't it? I'm not sure what you get in alphabet parameter, but either way, string is an array of chars, so you can also do "txtResult += alphabet[0]" instead of what you have there.
So, in total, you got it all right, the logic was right, you figured the main aspects. But you over complicated the whole thing. I believe you'll be fine after reading all this text, and wish you the best.
If you want to clear your Text object when you have succesfully entered your answer, you should not call your "BackSpace" function.
Just replace your code to this:
if (answer1 == int.Parse(userAnswer1.text))
{
score++;
userAnswer1.text = string.Empty;
This will clear the text element.
You could also look into using InputFields in Unity, which are designed for entering input and automatically support backspace and other keyboard functions.
If you do, make sure that you set the InputField's ContentType to either Integer Number or Decimal Number
Hi I am writing some code for my homework and I am stuck. I created one general click event handler for digit Buttons:
private void btnN_Click(object sender, EventArgs e),
and now I need to make frequency Array which I need to update every time when one of the button is clicked.
Here is freqArray:
private int[] freqArray = new int[10];
How can I do that if there is let say nine buttons?
Thank you
lastNum is number of buttons.
private void btnN_Click(object sender, EventArgs e)
{
for (int i = 0; i < lastNum; i++)
{
freqArray[i]++;
lstFrequencies.Items[i] = i + "\t\t" + freqArray[i];
}
}
Gosh, this is getting out of hand.. but since the original idea of giving hints and helping you along the way has hit the wall - I'll discuss the problem and will leave the decision to you..
The core problem is to identify within the common click event just which of the many buttons has been clicked. The key to this is usually in the event's parameters; in this case the sender is the button that got clicked.
We will look at three different ways to identify the sender:
By comparing it to the Control
By looking at its Name
By using an index stored in its Tag
So the simplest and most direct approach would be something like this:
if (sender == button1) freqArray[0]++;
else if (sender == button2) freqArray[1]++;
..
Note that while the designer names the controls you add with a count from 1 the programmers count from 0! (As do many data structures in C# including your array of counts!)
There are other approaches and since we are doing a little lesson here we go:
Sender is of the most basic type object; you can cast an object to its actual Type like this:
Button b = (Button) sender;
And now you can access all the button's properties, including the Name. So you could write the above code like this:
if (b.Name == "button1") freqArray[0]++;
else if (b.Name == "button2") freqArray[1]++;
..
This has un-coupled the actual button control from the identification and replaced it by a string.
And there is a general purpose property called Tag, which incidentally is also of class object; you can store anything in it. This makes it sometimes quite valuable and often one creates a special structure or even class just to store many things in a Tag..
So if you have created the Buttons to have their Tag contain an index you could use that:
freqArray[ (int) ( (Button) sender).Tag) ]++;
Note the double casts and all those parenthesis! It looks complicated and it is. It is just one line instead of the long vector of if clauses we saw before. But it only works if you have set the Tags before, maybe in the load event:
button1.Tag = 0;
button2.Tag = 1;
button3.Tag = 2;
...
So you have to invest first and can harvest later..
A lot to digest here.. Your pick!
One thing you must understand is you shouldn't ask for approach to a problem. However since your question requires it.
First you should add Tags to the buttons to differentiate them:
button1.Tag = "1";
button2.Tag = "2";
.
.
.
Then in your event handler cast the sender object to your control type:
Button a = (button)sender;
Then check the tag of the button a to add frequencies:
freqArray[Convert.ToString(a.Tag)-48] = freqArray[Convert.ToString(a.Tag)-48] + 1;
Im trying to create a TextBox control and force user to enter only numbers in specyfic format there.
How can I do it in WPF?
I have not found any properties like "TextFormat" or "Format" in TextBox class.
I made TextBox like this (not in visual editor):
TextBox textBox = new TextBox();
I want TextBox behavior like in MS Access forms, (user can put only numbers in that textbox in "000.0" format for example).
Consider using WPF's built in validation techniques. See this MSDN documentation on the ValidationRule class, and this how-to.
What you probably need is a masked input. WPF doesn't have one, so you can either implement it yourself (by using validation, for example), or use one of available third-party controls:
FilteredTextBox from WPFDeveloperTools
MaskedTextBox from Extended WPF Toolkit
etc.
Based on your clarification, you want to limit user input to be a number with decimal points.
You also mentioned you are creating the TextBox programmatically.
Use the TextBox.PreviewTextInput event to determine the type of characters and validate the string inside the TextBox, and then use e.Handled to cancel the user input where appropriate.
This will do the trick:
public MainWindow()
{
InitializeComponent();
TextBox textBox = new TextBox();
textBox.PreviewTextInput += TextBox_PreviewTextInput;
this.SomeCanvas.Children.Add(textBox);
}
Meat and potatoes that does the validation:
void TextBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
// change this for more decimal places after the period
const int maxDecimalLength = 2;
// Let's first make sure the new letter is not illegal
char newChar = char.Parse(e.Text);
if (newChar != '.' && !Char.IsNumber(newChar))
{
e.Handled = true;
return;
}
// combine TextBox current Text with the new character being added
// and split by the period
string text = (sender as TextBox).Text + e.Text;
string[] textParts = text.Split(new char[] { '.' });
// If more than one period, the number is invalid
if (textParts.Length > 2) e.Handled = true;
// validate if period has more than two digits after it
if (textParts.Length == 2 && textParts[1].Length > maxDecimalLength) e.Handled = true;
}
FastColoredTextbox is an user-control that can be downloaded in this url, it looks like this:
Its an amazing control but only can select one word when doubleclicking on the text, can't hold the mouse to select more words, so it only selects the entire current word over the mouse pointer even if you try to move the mouse cursor to left or right to select more text.
I have not found any information explaining the problem, and all of the official example projects has this problem.
Nobody means how to make an AutoWordSelection equivalent of a default TextBox for a FastcoloredTextbox control, but even the most important thing is:
How to select just more than one word with the mouse?
UPDATE:
#mostruash answer is very instructive but in all this time I could not carry out the modifications by myself.
I need a huge help from a C# programmer to carry out this task, my knowledge of C# is very low and the modifications that I made to the source did not work (don't compiled), I went back to the original user-control source to not end up spoiling more. I hate to say this but this time I need the job done, this source is too much for me.
If I'm requesting for too much then maybe with the necesary extended instructions of a C# developer, explaining how to accomplish this step by step, maybe I could carry it out by myself.
UPDATE
A video that demostrates the problem:
https://www.youtube.com/watch?v=Cs2Sh2tMvII
UPDATE
Another demo, I show what the FastColoredTextBox can't do but I would like to do like every other text-editor can do:
I've checked the source code of the project. Dragging is cancelled if a double click occurs and SelectWord is called.
You could modify the source code to include the feature that you request. (https://github.com/PavelTorgashov/FastColoredTextBox). In that case:
You must trace selections that start with double clicks.
Instead of calling SelectWord function, use the Selection class and draggedRange attribute to mark the selected word in OnMouseMove.
You also must handle deselection of words in OnMouseMove.
You must also select spaces between words in OnMouseMove.
The double click is handled in the code piece below:
if (!isLineSelect)
{
var p = PointToPlace(e.Location);
if (e.Clicks == 2)
{
mouseIsDrag = false; //Here, drag is cancelled.
mouseIsDragDrop = false;
draggedRange = null; //Drag range is nullified
SelectWord(p); //SelectWord is called to mark the word
return;
}
if (Selection.IsEmpty || !Selection.Contains(p) || this[p.iLine].Count <= p.iChar || ReadOnly)
OnMouseClickText(e);
else
{
mouseIsDragDrop = true;
mouseIsDrag = false;
}
}
EDIT:
This may require a lot of work to accomplish. So maybe you should use another tool/library. I have not studied the whole source code so there will probably be additional steps to those provided above.
For example, to trace double clicks you can do the following:
Define a class variable/property in FastColoredTextbox.cs: bool isDoubleClick.
Set it to true in OnMouseDown under if(e.Clicks == 2) condition. Set it to false in all other conditions.
Set it to false in OnMouseClick or OnMouseUp or in other relevant mouse event handlers.
That way you will know if series of mouse events had started with a double click event or not. Then you would act accordingly in OnMouseMove because that is where you (un)mark characters or (un)mark words.
LAST WORDS OF CAUTION:
The author of that project did not include any inline comments or any other means of documentation so you will be studying the code line by line to understand what each function/part does.
Add the following statement between Line 5276 and line 5277 in the class FastColoredTextBox.cs:
SelectWord(p);
mouseIsDrag = true; // here
return;
Note that implementing the ultimate behavior would require a good bunch of coding. Whereas the workaround mentioned above might satisfy your needs.
As #mostruash points out in his answer, that is the place where author cancels the mouse drag. Not sure why he deliberately prevents this feature. Only he knows.
if (e.Clicks == 2)//Line 5270
{
mouseIsDrag = false;
mouseIsDragDrop = false;
draggedRange = null;
SelectWord(p);
return;
}
I didn't read whole code, and I have no reason to do it. I just checked quickly and removed them. And it works as you expect.
if (e.Clicks == 2)//Line 5270
{
//Comment or remove completely.
//mouseIsDrag = false;
//mouseIsDragDrop = false;
//draggedRange = null;
SelectWord(p);
return;
}
Note: Am not sure this breaks something else, I've not tested. At least that works. Test it yourself.
My solution is a bit tweaky, but seems to work at first glance.
You have to make some changes in the Code:
Add mouseIsWholeWordSelection flag and a Range variable which can store the initial selected range after double click (best after line 100, I guess):
private bool mouseIsWholeWordSelection;
private Range mouseIsWholeWordSelectionBaseRange;
Change the selection code for double click event as stated above and extend it a bit (line 5222):
if (e.Clicks == 2)
{
//mouseIsDrag = false;
mouseIsDragDrop = false;
mouseIsWholeWordSelection = true;
//draggedRange = null;
SelectWord(p);
mouseIsWholeWordSelectionBaseRange = Selection.Clone();
return;
}
Add evaluation of dragging event for recreating selection (line 5566):
else if (place != Selection.Start)
{
if (mouseIsWholeWordSelection)
{
Selection.BeginUpdate();
var oldSelection = Selection.Clone();
SelectWord(place);
if (Selection.End >= mouseIsWholeWordSelectionBaseRange.End)
{
Selection.Start = (mouseIsWholeWordSelectionBaseRange.Start > Selection.Start) ? mouseIsWholeWordSelectionBaseRange.Start : Selection.Start;
Selection.End = mouseIsWholeWordSelectionBaseRange.End;
}
else if (Selection.Start < mouseIsWholeWordSelectionBaseRange.End)
{
Selection.Start = new Place(Selection.End.iChar, Selection.End.iLine);
Selection.End = mouseIsWholeWordSelectionBaseRange.Start;
}
Selection.EndUpdate();
DoCaretVisible();
Invalidate();
}
else
{
Place oldEnd = Selection.End;
Selection.BeginUpdate();
if (Selection.ColumnSelectionMode)
{
Selection.Start = place;
Selection.ColumnSelectionMode = true;
}
else
Selection.Start = place;
Selection.End = oldEnd;
Selection.EndUpdate();
DoCaretVisible();
Invalidate();
}
return;
}
Add at every place where isMouseDrag is being set to false:
isMouseWholeWordSelection = false;
And there you go.