Develop Reference

"input string was not in a correct format " RFID card reading through usb

I am trying to get the string value of an RFID card using C#. When I pass the 1st value, at the start of the string I get a symbol which I cannot identify. When I pass more values, the symbol changes.
I want to convert this string into integer value for further process. When I do that I am getting the error
Input string was not in correct format
I think the unidentified symbol that's preventing me from making this conversion.
Here is my code:
this.textBox1.Text = data;
x = Int32.Parse(data, System.Globalization.NumberStyles.HexNumber);
Console.WriteLine(x);
and also help me to show this x value in a separate textbox.

"and also help me to show this x value in a separate textbox."
I guess you could create a new TextBox and give it the value of x like:
TextBox textBox2 = new TextBox();
textBox2.Text = "This is the content of x: " + x;
textBox2.Show(); //Or textBox2.Visible = true;
I'm not quite sure about how to arrange the textbox since I've just used the GUI designer of VS so far, sorry mate. You could also create a textbox in the GUI Designer make it's visibility on false, until you gave the textbox the value of x and then set it's visibility on true again ;).
Have you tried Convert.ToInt32(yourInput); instead of Parse? I'm also a beginner in C# but maybe the parsing creates the unknown Letter?
I hope I was able to help you at least a bit, wish you a nice day and good luck! :-)

Textbox Number Formating & start with zero & accept only Numbers

I am using below Property example to make some calculation on textbox and if textbox is null I am assigning zero to it so calculation won't fail as you can see I am using Math.Round and I want to make several checks on these textbox input like
textbox that only accepts numbers I searched and found method 1
I want my textbox to be formated I searched and found Method 2
Now my question is ..
Is there any way to mareg all these method in the property method I am using
so my code won't be like "spaghetti code" ?
is there any better ways to do these checks ?
Thank you in advance
Property example
public double ItemPriceResult
{
get
{
return Math.Round(ItemCost * RevenuePercentage / 100 + ItemCost, 0);
}
}
Method 1
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "[^0-9]"))
{
MessageBox.Show("Please enter only numbers.");
textBox1.Text = textBox1.Text.Remove(textBox1.Text.Length - 1);
}
}
Method 2
textBox1.Text = string.Format(System.Globalization.CultureInfo.GetCultureInfo("id-ID"), "{0:#,##0.00}", double.Parse(textBox1.Text));
UPDATE after some answers
MaskedTextBox seems fit my needs I read and searched and below some question
if you kindly would like to help me
I need to use MaskedTextBox because I can set it to accept
number and I can also force number formating so
also I need to make number textboxs easer to read for users
so 1000 will be come 1,000
and 10000 will be come 10,000
then according to Microsoft Docs formating MaskedTextBox to fit my needs
Masked MaskedTextBox with 999,999,999,
second I do not want the PromptCharto be visible I google it but none of search result did it

Try this , it will accept only numbers and u can format the string as u want using regex.
public static string ToMaskedString(this String value)
{
var pattern = "^(/d{2})(/d{3})(/d*)$";
var regExp = new Regex(pattern);
return regExp.Replace(value, "$1-$2-$3");
}

You have a TextBox. Alas you don't tell what kind of TextBox you use. System.Windows.Forms.TextBox? System.Web.UI.MobileControls.TextBox?
You write "if text box is null I am assigning zero to it". I assume that you mean that if no text is entered in the text box you assume that 0 is entered.
Furthermore you want to format the output of the text box whenever the text is changed. So while the operator is typing text you want to change this text? For the operator this is very annoying.
Wouldn't you prefer that the operator is obliged to type his text in the format you desire, helping him visually. For this you may use the class MaskedTextBox
The MaskedTextBox has a property Mask, which forces the operator to type in a certain format. I'm not really familiar with what you do with the format {0:#,##0.00}, but I assume you want the output double in a real format with two digits after the decimal point using the decimal point and the thousand separator as common in the current culture.
via the designer put in initialize component:
this.maskedTextBox1.Mask = "99990.00";
after adding the event for text changed:
private void maskedtextBox1_TextChanged(object sender, EventArgs e)
{
double enteredValue = 0.0; // value to use when empty text box
if (!String.IsNullOrEmpty(this.maskedtextBox1.Text))
{
enteredValue = double.Parse(maskedTextBox1.Text, myFormatProvider)
}
ProcessEnteredValue(enteredValue);
}
}

After your edit, the specifications have changed.
While entering the number in the text box, the operator should not have any visual feedback of the formatting of his number.
The operator is free to enter the real number in any commonly used format.
The value of the text box should not be used while the operator is editing the text box.
Only after editing is finished, the value of the text box should be interpreted for correctness, and if correct it should be used.
The actually used value should be displayed in the text box in a defined format.
The desire not to show any visual feedback while entering is understandable. After all, the program doesn't care whether the operator types 1000, 1000.00, or even 1.0E3.
The MaskedTextBox is especially used to force the operator to enter his number in a given format. Since this is not desired, my advise would be to use a TextBox instead of aMaskedTextBox.
However, because you give the operator the freedom to enter his number in any way he wants, including copy-paste, repairing typing errors, etc. you'll have to add the possibility for the user to express to the program that he has finished entering the number.
An often used method in the windows UI would be a Button. Another possibility would be the enter button. Be aware though that this is not really standard within windows. It might make learning your program a little bit more difficult.
So after the operator notified that he finished editing and the corresponding event function is called, your code could be:
// Get the numberformat to use, use current culture, or your own format
private readonly IFormatProvider myNumberFormat = CultureInfo.CurrentCulture.NumberFormat
private void OperatorFinishedEditing(TextBox box)
{
// read the text and try to parse it to a double
// accepting all common formats of real numbers in the current culture
bool valueOk = true;
double resultValue = 0;
if (!String.IsNullOrEmpty(box.Text))
{
bool valueOk = Double.TryParse(box.Text, out resultValue);
}
if (valueOk)
{
box.Text = FormatResultValue(resultValue);
ProcessValue(resultValue);
}
else
{
ShowInputProblem();
}
}

Formatting a string to display custom decimal values

I'm trying to format some doubles properly so that they will display properly for my uses (I'm building a statement in Devexpress, so I'm working with a lot of numbers).
Here are the basic formatting rules I'd like to have happen:
1000.2 -> 1,000.20
1000 -> 1,000
1000.22 -> 1,000.22
Is this possible using string formatting in C#? I've tried the following, but not been able to achieve my goal:
#,#.## - gives me 1,000.2 for the first value
#,#.#0 - gives me 1,000.00 for the second value
#,#.00 - gives me 1,000.00 for the second value
EDIT: Some more information. DevExpress gives me the ability to use string formatting to set up the values after they've been bound to the report. We're doing it at report time (and not at calculation time in the behind the scenes code) because we use the Sum function within the tables that DevExpress offers us. The reason we do THAT is so that we can minimize calls to our database by doing one large pull of data, then using that table over and over again in the statement and filtering based on the restrictions within.
EDIT EDIT:
Based on the feedback I've receieved here in the comments, it's not possible to perform the formatting I'd like to do with only providing a string format; I would need to insert some code either when I provide the data to the report (and then remove any and all formatting from the report) and perform all summing functions at the code level (to ensure that the sum values have the expected decimal places), or I would need to accept .00 at the end of, for example, some amount of yen (100 JPY would never be represented as 100.00 JPY, as an example).
This is a bit of an esoteric case, but it's good to know!

You can use string formatting coupled to a simple if condition. To shorten it's use, you can also make it an Extension method. It can look like this :
public static string FormatConditionnaly(this double input)
{
return input % 1 == 0 ? input.ToString("#,0") : input.ToString("#,0.00");
}
Basically, if you number does not contain any decimals (the % 1 == 0 check), you format it without decimals. If it fails the check, you add the two zeroes.
It is used like that :
const double flatNumber = 1000;
string result1 = flatNumber.FormatConditionnaly(); //1,000
const double numberWithDecimals = 1000.5;
string result2 = numberWithDecimals.FormatConditionnaly(); //1,000,50

Bit of a hack but you can give this a try:
s = String.Format("{0:N2}", 1000).Replace(".00", "");

Use the "N" format specifier as the format string when you call ToString(); See here
For example:
int intValue = 123456789;
Console.WriteLine(intValue.ToString("N2",
CultureInfo.InvariantCulture).Replace(".00", "");
You can customize group sizes etc. as needed.

Why don't you format the values before binding to DevExpress control using plain old C# (Assuming you are doing a bind, as you have not given sufficient details.)
In c# the Math.Round() should do the trick.
Example Math.Round(doubleValue,2) where the second parameter is the number of decimal places.
EDIT:
#,##0.00
I Do not have DevExpress controls to test my solution but I did find http://documentation.devexpress.com/#windowsforms/CustomDocument1498 online (not sure if you see it already).
It seems you can use the Number or Currency masks.
Also take a look at the Zero Placeholder under the custom section. based on the description, '0' is filled where the user has not supplied a value.
example: 123.4 --> 123.40

If the string that you're trying to format is in an XRTableCell of an XtraReport instance, you can handle the BeforePrint event on that cell to format its text. This event is triggered anytime that the report is rendered. Call GetCurrentColumnValue to retrieve the value that you want to format, use any of the code methods from the previous answers that will work for you, and then set that cell's text with your formatted string. Using #dweeberly's answer:
private void OnBeforePrint(object sender, PrintEventArgs e)
{
object value = this.GetCurrentColumnValue("YourField");
if (value != null)
{
yourCell.Text = String.Format("{0:N2}", value.ToString()).Replace(".00", "");
}
}

Based on the feedback I've receieved here in the comments, it's not possible to perform the formatting I'd like to do with only providing a string format; I would need to insert some code either when I provide the data to the report (and then remove any and all formatting from the report) and perform all summing functions at the code level (to ensure that the sum values have the expected decimal places), or I would need to accept .00 at the end of, for example, some amount of yen (100 JPY would never be represented as 100.00 JPY, as an example).
This is a bit of an esoteric case, but it's good to know!

Windows Forms - customizing MaskedTextBox

I need to use basic functionality of the MaskedTextBox. I can get use of the 5 digit mask but there are few things that I want to change. Right now the box is looking like this:
and there are two thing I don't like. First - the Prompt char which is undersoce _. I deleted the field value in order to leave it empty (as I would like it to appear) but this gives an error - The property value is invalid. So is there a way to get rid of these underscores? And second - I use this value for one of my entity properties which is of integer type so I make a convertion :
if (txtNumOfAreas.Text != "")
{
string temp = txtNumOfAreas.Text;
bool result = Int32.TryParse(temp, out convertValue);
if (result)
{
entity.AreasCnt = convertValue;
}
else
{
MessageBox.Show(Resources.ERROR_SAVE, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
return false;
}
}
else
{
entity.AreasCnt = null;
}
which works fine unless someone decides to make experiments and insert something like _1__5_ then the conversion fails, but at first place I would like to make possible to write the digits only one after another. So is this possible too?

It looks like your MaskedEdit is more trouble than it's worth to deal with your particular range of issues. A better control to use might be the NumericUpDown.
The upside to NumericUpDown:
There are no underscore prompts to try and get rid of
It will only accept numeric input
So there is no need to try and convert the value. You will always have an integer
Setting Minimum and Maximum value properties gives you automatic data entry validation
Provides multiple modes of data entry:
Typing
Clicking up/down buttons with a mouse
Up/down with keyboard
If you like, you could hide the up/down buttons altogether: C# WinForms numericUpDown control (removing the spin box)

So to get the _ to be a space you just need to set the mask character to a single space. And to resolve the conversion error, just set the AllowPromptAsInput property to false so that the user can't actually end up with something like your example.

How to pass decimal value from textbox to parameter

I am trying to create a save Button and it includes 2 values in TextBox controls that are considered currency in sql. They are decimal in the TextBox. How do I pass the value? I tried this to no avail:
decimal taxOpen = Convert.ToDecimal(taxOpenTextBox).Text;
Any help on the correct syntax would be great.

You need to access the Text property. You also should use TryParse, which returns false instead of throwing an exception if the parse fails:
decimal value;
if(!decimal.TryParse(taxOpenTextBox.Text,
NumberStyles.Currency,
NumberFormatInfo.InvariantInfo,
out value))
MessageBox.Show("Please enter a valid number");
The needed things are found in System.Globalization.

You need to get the value of the taxOpenTextBox, not the box itself.