Develop Reference

RegularExpressionValidation - is there a better way to write this?

I have a textbox that the requirements are for it to be five numeric characters followed by 3 letters that will match what was selected in a dropdownlist. This is the way I'm having it check:
protected void ddlLegalEntity_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddlLegalEntity.SelectedItem.Text == "FID")
{
RegularExpressionValidator1.ValidationExpression = "^[0-9]{5}(FID)$";
}
else if (ddlLegalEntity.SelectedItem.Text == "FLM")
{
RegularExpressionValidator1.ValidationExpression = "^[0-9]{5}(FLM)$";
}
else if (ddlLegalEntity.SelectedItem.Text == "FOF")
{
RegularExpressionValidator1.ValidationExpression = "^[0-9]{5}(FOF)$";
}
And then it continues with a few more else if.......
So if in ddlLegalEntity you select the choice FLM, then the textbox will have to equal five numbers followed by FLM.
Such as...
13423FLM
56543FLM
This code works fine, but I feel like there must be an easier way to code this. maybe I'm wrong and this is the easiest way, but I'm just curious.

Maybe something like:
protected void ddlLegalEntity_SelectedIndexChanged(object sender, EventArgs e)
{
RegularExpressionValidator1.ValidationExpression = "^[0-9]{5}("+ddlLegalEntity.SelectedItem.Text+")$";
}
And better use string.Format( string, params) for this purposes;
private static readonly string validationRegEx= "^[0-9]\{5\}({0})$";
String.Format(validationRegEx, ddlLegalEntity.SelectedItem.Text);

c# TextBox how to get the last letter of a string?

private void inputBox_KeyPress(object sender, KeyPressEventArgs e)
{
stringScan();
var regex1 = new Regex(#"[^+^\-^\b^\r\n]");
var regex2 = new Regex(#"[^0-9^+^\-^/^*^#^\b^\r\n]");
if (ListBox.Items.Count == 0 && string.IsNullOrWhiteSpace(inputBox.Text))
{
if (regex1.IsMatch(e.KeyChar.ToString()))
{
e.Handled = true;
toolTip1.Show("Plus or minus first then followed by numbers.", inputBox, 1500);
}
}
else
{
if (regex2.IsMatch(e.KeyChar.ToString()))
{
e.Handled = true;
}
}
}
public void stringScan()
{
char last_char = inputBox.ToString()[inputBox.ToString().Length - 1];
Console.WriteLine(last_char);
}
How can i get the last letter/number of a string?. Its really hard to explain so I'll show some screenshots.
the output should show "0" not "1".
It always show the "previews last" and not the latest one that i typed in the textbox.

Remember, when the event inputBox_KeyPress is raised, the typed key isn't added yet. Also, don't use regex for this. It will be overcomplicated.
Try the TextChanged event.

Text box key change will be executed every time u change the content of the text box
So for every value u enter u will be calling the string scan
This can be limited if u know what length the text is going to be

What about you try this:
public void stringScan()
{
String last_char = inputBox.ToString();
Console.WriteLine(last_char[last_char.Length-1]);
}

If you want last typed char I suggest:
private void inputBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
Console.WriteLine(e.Text);
}
If you want last char in textbox I suggest TextChanged event as already told by Jeroen van Langen:
private void inputBox_TextChanged(object sender, TextChangedEventArgs e)
{
string inputString = ((TextBox)sender).Text;
char lastChar = inputString.Last();
Console.WriteLine(lastChar);
}
Hope code samples help you
Edit:
Now I get that you probably want to get integer from textbox, if that's the matter, Get integer from Textbox could help you, code sample:
private void inputBox_TextChanged(object sender, TextChangedEventArgs e)
{
string inputString = ((TextBox)sender).Text;
int valueFromTextBox;
if (int.TryParse(inputString, out valueFromTextBox))
{
//parsing successful
}
else
{
//parsing failed.
}
}

Need help clearing and restoring clicked textboxes

I'm attempting to create a TimeCard application for employees to be able track their hours through an application instead of having to write down their hours manually. I have a decent amount of textboxes that i need to check.
First, I want to check if the textbox is clicked it will clear the value that is currently in that textbox.
Second, I want to check the textboxes again, if the user clicks out of the textbox and didn't insert any values(hours) in the textbox(blank textbox) it will automatically return the text back to 0(hours).
I am using the 'MouseClick' property to assign all these textboxes. The first part of mode code works correctly.When a user clicks on the box it clears the 0 text that was there before, but I can't figure out how to return that 0 value. Once the textbox is clicked it clears the textbox and leave it blank.I've seen ways that you can do it one at a time, but i'm trying to learn how to code efficiently. Any guidance and help on this situation would be greatly appreciated. Thank You.
Tools: C# / Visual Studio 2012 / Microsoft SQL 2012
private void MainForm_Load(object sender, EventArgs e)
{
foreach (Control control1 in this.Controls)
{
if (control1 is TextBox)
{
control1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.AllTextBoxes_Click);
}
}
}
//Mouse Click Clear
private void AllTextBoxes_Click(object sender, MouseEventArgs e)
{
if ((sender is TextBox))
{
((TextBox)(sender)).Text = "";
}
}

If I understand your requirements, what you actually want is a Watermark/Cue banner implementation.
But since I could be monstruosly wrong, here is an implementation of what you're trying to accomplish.
private void MainForm_Load(object sender, EventArgs e)
{
foreach (Control c in this.Controls)
{
if (c is TextBox)
{
c.GotFocus += deleteContent_GotFocus; // No need for more than that ;)
c.LostFocus += restoreContent_LostFocus;
}
}
}
private void deleteContent_GotFocus(object sender, EventArgs e)
{
if ((sender is TextBox))
{
// Using "as" instead of parenthesis cast is good practice
(sender as TextBox).Text = String.Empty; // hey, use Microsoft's heavily verbosy stuff already! :o
}
}
private void restoreContent_LostFocus(object sender, EventArgs e)
{
if ((sender is TextBox))
{
TextBox tb = sender as TextBox;
if (!String.IsNullOrEmpty(tb.text)) // or String.IsNullOrWhiteSpace
tb.Text = "0";
}
}

c# apply same rules to all textboxes

I have several text boxes and would like to format them all the same way with these rules:
// limits to number, control keys, and decimal
// goes to the next text box when enter
private void tb_text1_KeyPress_1(object sender, KeyPressEventArgs e)
{
string newString = Regex.Replace(tb_text1.Text, "[^.0-9]", "");
tb_text1.MaxLength = 6;
e.Handled = (!char.IsDigit(e.KeyChar) && !Char.IsControl(e.KeyChar) && e.KeyChar != '.');
if (e.KeyChar == (char)(Keys.Enter))
{
this.GetNextControl(ActiveControl, true).Focus();
}
}
// removes restricted chars
private void tb_text1_Enter(object sender, EventArgs e)
{
tb_text1.Text = Regex.Replace(tb_text1.Text, "[^.0-9]", "");
}
// applies format at exit
private void tb_text1_Leave(object sender, EventArgs e)
{
tb_text1.Text = string.Format("{0,-6} [Ohm]", decimal.Parse(tb_text1.Text));
}
What is the best way? create a new text box class based on the text box?
Thanks.

Replace in methods your "tb_text1" variable to the "((TextBox)sender)", and now You can use Your code for any textbox.

It is very easy to do it with javascript . Please try that. I have done it i'm not able to find piece of that code right now . It is worth the effort because it will be very fast and will be running on client side.

Textbox for price/cash/currency on C#

I have a problem that is haunting me for a while. I tried some solutions but they didn't worked.
I have a textbox that is for cash input ($999,99 for example). However I need to automatically input the "," and "." to display the value correctly.
I tried two solutions. One of them is this:
private void tx_ValorUnidade_TextChanged(object sender, EventArgs e)
{
string value = tx_ValorUnidade.Text.Replace(",", "").Replace("R$", "");
decimal ul;
//Check we are indeed handling a number
if (decimal.TryParse(value, out ul))
{
//Unsub the event so we don't enter a loop
tx_ValorUnidade.TextChanged -= tx_ValorUnidade_TextChanged;
//Format the text as currency
tx_ValorUnidade.Text = string.Format(System.Globalization.CultureInfo.CreateSpecificCulture("pt-BR"), "{0:C2}", ul);
tx_ValorUnidade.TextChanged += tx_ValorUnidade_TextChanged;
}
}
The result, however, is very weird.
The other one is this:
private void tx_ValorUnidade_KeyUp(object sender, KeyEventArgs e)
{
if (!string.IsNullOrEmpty(tx_ValorUnidade.Text))
{
System.Globalization.CultureInfo culture = new System.Globalization.CultureInfo("en-US");
int valueBefore = Int32.Parse(tx_ValorUnidade.Text, System.Globalization.NumberStyles.AllowThousands);
tx_ValorUnidade.Text = String.Format(culture, "{0:N0}", valueBefore);
tx_ValorUnidade.Select(tx_ValorUnidade.Text.Length, 0); *
}
}
This one kinda works, but there is a issue: if the user wants to insert somethink like $10,00 it can't. It also crashes after 5 numbers.
For original reference, I got the 2 codes from other questions here.
How can I fix it? Am I using the examples wrong? Any thought is welcome.

I think you will be better off when formatting when the user moves to the next control, e.g. like below. Otherwise it will be very confusing as the text will change itself as the user is typing:
private void textBox1_Leave(object sender, EventArgs e)
{
Double value;
if (Double.TryParse(textBox1.Text, out value))
textBox1.Text = String.Format(System.Globalization.CultureInfo.CurrentCulture, "{0:C2}", value);
else
textBox1.Text = String.Empty;
}

Some people might want to actually format a textbox as they type. So this is my solution if anyone is looking for one.
It actually assumes you are entering one digit at a time so therefore as you press "1" it assumes "$0.01" and when they press "2" it then assumes "$0.12" and so on and so forth.
I could not find anything online about formatting as they typed. It has been tested and if any errors let me know.
private void textBox1_TextChanged(object sender, EventArgs e)
{
//Remove previous formatting, or the decimal check will fail including leading zeros
string value = textBox1.Text.Replace(",", "")
.Replace("$", "").Replace(".", "").TrimStart('0');
decimal ul;
//Check we are indeed handling a number
if (decimal.TryParse(value, out ul))
{
ul /= 100;
//Unsub the event so we don't enter a loop
textBox1.TextChanged -= textBox1_TextChanged;
//Format the text as currency
textBox1.Text = string.Format(CultureInfo.CreateSpecificCulture("en-US"), "{0:C2}", ul);
textBox1.TextChanged += textBox1_TextChanged;
textBox1.Select(textBox1.Text.Length, 0);
}
bool goodToGo = TextisValid(textBox1.Text);
enterButton.Enabled = goodToGo;
if (!goodToGo)
{
textBox1.Text = "$0.00";
textBox1.Select(textBox1.Text.Length, 0);
}
}
private bool TextisValid(string text)
{
Regex money = new Regex(#"^\$(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?$");
return money.IsMatch(text);
}
To make it look nice I'd recommend starting the text box with the text $0.00 on the form load like so:
private void Form1_Load(object sender, EventArgs e)
{
textBox1.Text = "$0.00";
textBox1.SelectionStart = inputBox.Text.Length;
}

Just a slight modification to GreatNates answer.
private bool KeyEnteredIsValid(string key)
{
Regex regex;
regex = new Regex("[^0-9]+$"); //regex that matches disallowed text
return regex.IsMatch(key);
}
and insert this method into the textboxs preview input event like this.
private void TextBox1_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
e.Handled = KeyEnteredIsValid(e.Text);
}
That way you make sure that you can't make any mistakes when typing anything. You are limited to numbers only with my methods, while nates methods are formatting your string.
Cheers.

We can try following one as well.
txtCost.Text = String.Format("{0:c2}", myObj.Cost);

I struggled with this for hours too. I tried to use maskedTextBox but that was just clunky for the users to enter text. I also didn't like having to deal with the masking for calculations. I also looked into using the databinding formatting but that just seemed overkill.
The way I ended up going was not to use a TextBox for inputting numbers. Use the NumericUpDown object instead. No need conversion and you can set your decimals and thousands commas in the properties if you like ;) I set my increment to 1000 since i was dealing with income.
Do be aware that the .Text that comes through will have commas when there is a penny decimal and amount over 1000 (i.e. 1,000.01) , otherwise the decimal and trailing 0s are dropped.
I also found this short and sweet solution which worked well but was unneccesary with numericUpDown. You can put this on leave event.
Decimal val;
if (Decimal.TryParse(TxtCosPrice.Text, out val))
TxtCosPrice.Text = val.ToString("C");
else
MessageBox.Show("Oops! Bad input!");

This is my solution, it puts only dots, not money symbol. Hope can help somenone.
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
e.SuppressKeyPress = TextBox2Currency((TextBox)sender, e.KeyValue);
}
private bool TextBox2Currency(TextBox sender,int keyval)
{
if ((keyval >= 48 && keyval <= 58) || keyval == 46 || keyval == 8)
{
int pos = sender.SelectionStart;
int oriLen = sender.Text.Length;
string currTx = sender.Text.Replace(".", "").ToCurrency();
int modLen = currTx.Length;
if (modLen != oriLen)
pos += (modLen - oriLen);
sender.Text = currTx;
if ( pos>=0)
sender.SelectionStart = pos;
return false;
}
return true;
}