I have a textbox that allows users to input a decimal values that then gets stored in the a table in the database, this piece of code works in the development environment. I have now published the my project to the server and now is not longer taking the values with the decimal places.
decimal ReceiptAmount;
decimal AmountDue;
decimal Change;
if (!string.IsNullOrEmpty(((TextBox)dl_Item.FindControl("tb_ReceiptAmount")).Text))
{
if (((TextBox)dl_Item.FindControl("tb_ReceiptAmount")).Text.Contains(".") == true)
{
ReceiptAmount = Convert.ToDecimal(((TextBox)dl_Item.FindControl("tb_ReceiptAmount")).Text.Replace(".", ","));
}
else
{
ReceiptAmount = Convert.ToDecimal(((TextBox)dl_Item.FindControl("tb_ReceiptAmount")).Text);
}
}
else
{
ReceiptAmount = 0;
}
if (!string.IsNullOrEmpty(((TextBox)dl_Item.FindControl("tb_AmountDue")).Text))
{
if (((TextBox)dl_Item.FindControl("tb_AmountDue")).Text.Contains(".") == true)
{
AmountDue = Convert.ToDecimal(((TextBox)dl_Item.FindControl("tb_AmountDue")).Text.Replace(".", ","));
}
else
{
AmountDue = Convert.ToDecimal(((TextBox)dl_Item.FindControl("tb_AmountDue")).Text);
}
}
else
{
AmountDue = 0;
}
if (!string.IsNullOrEmpty(((TextBox)dl_Item.FindControl("tb_Change")).Text))
{
if (((TextBox)dl_Item.FindControl("tb_Change")).Text.Contains(".") == true)
{
Change = Convert.ToDecimal(((TextBox)dl_Item.FindControl("tb_Change")).Text.Replace(".", ","));
}
else
{
Change = Convert.ToDecimal(((TextBox)dl_Item.FindControl("tb_Change")).Text);
}
}
else
{
Change = 0;
}
I am not to sure what seems to be the problem with this piece of code. The Textbox are found in a datalist that I loop through to get all of the values.
The Convert.ToDecimal overload that takes a string as input will parse the string using the CultureInfo.CurrentCulture. Probably your server has different regional settings. Depending on regional settings, a comma or point may be either interpreted as a thousand separator (and thus ignored) or as the decimal separator.
Instead, you should use Decimal.Parse directly, providing either a specific culture or the invariant culture, depending on your use case.
Ideally, you'd set the culture of the user somewhere. To achieve this there are multiple approaches, e.g. for ASP.Net Web forms: https://msdn.microsoft.com/en-us/library/bz9tc508.aspx
If you parse the string using the correct culture, you can get rid of the string manipulation for replacing . with ,.
First of all, lines like
if (!string.IsNullOrEmpty(((TextBox)dl_Item.FindControl("tb_ReceiptAmount")).Text))
look very ugly; let's extract a method (copy/paste is very, very bad practice):
private String FindDLText(String controlName) {
var box = dl_Item.FindControl(controlName) as TextBox;
return box == null ? null : box.Text;
}
Then you don't need checking Text.Contains(".") == true, just Replace if you really need it:
private Decimal FindDLValue(String controlName) {
String text = FindDLText(controlName);
if (String.IsNullOrEmpty(text))
return 0.0M;
//TODO: check if you really need this
//text = text.Replace(".", ",");
// you have to specify Culture either InvariantCulture or some predefined one;
// say, new CultureInfo("ru-RU") // <- use Russian Culture to parse this
return Decimal.Parse(text, CultureInfo.InvariantCulture);
}
Finally, you can get
decimal ReceiptAmount = FindDLValue("tb_ReceiptAmount");
decimal AmountDue = FindDLValue("tb_AmountDue");
decimal Change = FindDLValue("tb_Change");
feel the difference: three evident lines and two simple methods.
Related
I am using Convert.ToDecimal in linq, sometime amount value contains dot (.) as user want to write .50 or similar, as soon as they enter dot (using Numeric keypad from mobile), code is getting executed and throwing an exception.
I am getting string is not correct format exception for below code
var enteredAmountInTenders = TenderListCollection.Sum(x => Convert.ToDecimal(string.IsNullOrEmpty(x.Amount) ? "0" : x.Amount));
How can I ignore dot for above code and just get 0?
I would use decimal.TryParse instead of Convert.ToDecimal to cast the value.
var enteredAmountInTenders = TenderListCollection
.Sum(x => !decimal.TryParse(x.Amount,out var result) ? 0 : result);
you could check this before your set your property for the object in your TenderListCollection.
private string _amount = "0";
public string Amount
{
get
{
return _amount;
}
set
{
if(!string.IsNullOrEmpty(value))
{
if(value != ".")
{
_amount = value;
}
}
}
}
In general i dont like storing amounts as string, so i also would suggest to rename the Amount to GivenAmount and have an Amount Property which is a decimal, this way our code is clean and you dont need to parse in a Lambda expression.
The problem:
Let's assume you are using a dot "." as a decimal separator in your regional setting and have coded a string with a comma.
string str = "2,5";
What happens when you decimal.TryParse(str, out somevariable); it?
somevariable will assume 0.
What can you do to solve it?
1-
You can
decimal.TryParse(str, NumberStyles.Any, CultureInfo.InvariantCulture, out somevariable);
And it will return 25, and not 2.5 which is wrong.
2-
You can
decimal.TryParse(str.Replace(",","."), out num);
And it will return the proper value, BUT, if the user uses "," as a decimal separator it will not work.
Possible solution that I can't make it work:
Get the user decimal separator in regional settings:
char sepdec = Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator);
And make somehow the replace from ",",sepdec , that way it would stay a comma if its a comma, and replace by an actual dot if the user uses dots.
Hints?
Edit: Many users posted useful information, lately, using the arguments NumberStyles.Any, CultureInfo.GetCultureInfo("pt-PT") on a tryParse wouldn't work if your separator is set to "," So it pretty much doesnt fullfill the premise of making a tryparse "universal".
I'll work around this, if anyone has more hints you'r welcome
I know the thread is a little bit older, but I try to provide an answer.
I use regular expression to determine the used number format in the string.
The regex also matches numbers without decimal separators ("12345").
var numberString = "1,234.56"; // en
// var numberString = "1.234,56"; // de
var cultureInfo = CultureInfo.InvariantCulture;
// if the first regex matches, the number string is in us culture
if (Regex.IsMatch(numberString, #"^(:?[\d,]+\.)*\d+$"))
{
cultureInfo = new CultureInfo("en-US");
}
// if the second regex matches, the number string is in de culture
else if (Regex.IsMatch(numberString, #"^(:?[\d.]+,)*\d+$"))
{
cultureInfo = new CultureInfo("de-DE");
}
NumberStyles styles = NumberStyles.Number;
bool isDouble = double.TryParse(numberString, styles, cultureInfo, out number);
HTH
Thomas
I just want to say that HTH Thomas solution worked really well in my project, except for when trying to parse negative decimal numbers with commas. One solution to this, which is probably not optimized because I don't fully understand the regex Ismatch code, but that works is adding the possibility of finding a "-" before the number in the ifs statements, like this:
var cultureInfo = CultureInfo.InvariantCulture;
if (Regex.IsMatch(equation.inputFieldsTexts[i], #"^(:?[\d,]+\.)*\d+$") || Regex.IsMatch(equation.inputFieldsTexts[i], #"^(:?[-\d,]+\.)*\d+$"))
{
cultureInfo = new CultureInfo("en-US");
}
// if the second regex matches, the number string is in DE culture
if (Regex.IsMatch(equation.inputFieldsTexts[i], #"^(:?[\d.]+,)*\d+$") || Regex.IsMatch(equation.inputFieldsTexts[i], #"^(:?[-\d.]+,)*\d+$"))
{
cultureInfo = new CultureInfo("de-DE");
}
The solution I use is to simply show the user what the parsed value is.
I have a custom TextBox control which verifies the input when the control loses focus and such. If the control expects a floating point value (which is a property), then it will try to parse the value entered. If the TryParse succeeds, I display the out value in the control's text.
This way, when a user enters 12.3 the value might change to 123 because in the current culture 12,3 is expected. It's then up to them to decide to correct this.
How about this method:
clean the string from anything else than numbers, dot, comma and negative sign
take the last index of dot or comma
split the clean string and remove all thousands separators from the first part
convert both parts to integer
change the sign of the second part if necessary
add the first part with the second part divided by decimal places
public static bool TryParseDoubleUniversal(this string s, out double result) {
result = 0.0;
if (string.IsNullOrEmpty(s)) return false;
var clean = new string(s.Where(x => char.IsDigit(x) || x == '.' || x == ',' || x == '-').ToArray());
var iOfSep = clean.LastIndexOfAny(new[] { ',', '.' });
var partA = clean.Substring(0, iOfSep).Replace(",", string.Empty).Replace(".", string.Empty);
var partB = clean.Substring(iOfSep + 1);
if (!int.TryParse(partA, out var intA)) return false;
if (!int.TryParse(partB, out var intB)) return false;
if (intA < 0) intB *= -1;
var dp = double.Parse("1".PadRight(partB.Length + 1, '0'));
result = intA + intB / dp;
return true;
}
The question is old but since it was my first hit on Google. And the approach in How to change symbol for decimal point in double.ToString()? seems to be a valid solution you can use the NumberFormatInfo to set the decimal separator like this:
string value = "3,2";
NumberFormatInfo nfi = new NumberFormatInfo();
nfi.NumberDecimalSeparator = ",";
decimal.TryParse(value, NumberStyles.Any, nfi, out decimal dec);
I found a solution, I'm a beginner on this regional and comma-dots theme so if you have comments to improve the understanding of this please be welcome.
We start of by getting what decimal separator the user has set in his regional options outside before the Form{InitializeComponent();} (I want a universal variable that will allow me to correct the code)
char sepdec = Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator);
In the tryParse, to get it to behave universally we will read the dots and commas in the string, and turn them into the decimal separator we defined as sepdec
decimal.TryParse(str.Replace(",",sepdec.ToString()).Replace(".",sepdec.ToString()), out somevariable);
I hope this helps, please comment improvement suggestions!
In Android Xamarin, I ran into the same issue several times. Some solutions worked until the Android got upgraded into a new version, then the problem came out again. So I came with an universal solution, which works fine. I read the numeric input as text, then parse it into decimal with a custom parser.
The custom parser is returning 0 when parsing into decimal is not possible. It does allow input text containing decimal number with either comma or dot, with no group separators:
public static decimal ParseTextToDecimal(string decimalText)
{
if (decimalText == String.Empty) return 0;
string temp = decimalText.Replace(',', '.');
var decText = temp.Split('.');
if (!Int32.TryParse(decText[0], out int integerPart)) return 0;
if (decText.Length == 1) return integerPart;
if (decText.Length == 2)
{
if (!Int32.TryParse(decText[1], out int decimalPart)) return 0;
decimal powerOfTen = 10m;
for (int i = 1; i < decText[1].Length; i++) powerOfTen *= 10;
return integerPart + decimalPart / powerOfTen;
}
return 0; // there were two or more decimal separators, which is a clear invalid input
}
I have a long string with double-type values separated by # -value1#value2#value3# etc
I splitted it to string table. Then, I want to convert every single element from this table to double type and I get an error. What is wrong with type-conversion here?
string a = "52.8725945#18.69872650000002#50.9028073#14.971600200000012#51.260062#15.5859949000000662452.23862099999999#19.372202799999250800000045#51.7808372#19.474096499999973#";
string[] someArray = a.Split(new char[] { '#' });
for (int i = 0; i < someArray.Length; i++)
{
Console.WriteLine(someArray[i]); // correct value
Convert.ToDouble(someArray[i]); // error
}
There are 3 problems.
1) Incorrect decimal separator
Different cultures use different decimal separators (namely , and .).
If you replace . with , it should work as expected:
Console.WriteLine(Convert.ToDouble("52,8725945"));
You can parse your doubles using overloaded method which takes culture as a second parameter. In this case you can use InvariantCulture (What is the invariant culture) e.g. using double.Parse:
double.Parse("52.8725945", System.Globalization.CultureInfo.InvariantCulture);
You should also take a look at double.TryParse, you can use it with many options and it is especially useful to check wheter or not your string is a valid double.
2) You have an incorrect double
One of your values is incorrect, because it contains two dots:
15.5859949000000662452.23862099999999
3) Your array has an empty value at the end, which is an incorrect double
You can use overloaded Split which removes empty values:
string[] someArray = a.Split(new char[] { '#' }, StringSplitOptions.RemoveEmptyEntries);
Add a class as Public and use it very easily like convertToInt32()
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
/// <summary>
/// Summary description for Common
/// </summary>
public static class Common
{
public static double ConvertToDouble(string Value) {
if (Value == null) {
return 0;
}
else {
double OutVal;
double.TryParse(Value, out OutVal);
if (double.IsNaN(OutVal) || double.IsInfinity(OutVal)) {
return 0;
}
return OutVal;
}
}
}
Then Call The Function
double DirectExpense = Common.ConvertToDouble(dr["DrAmount"].ToString());
Most people already tried to answer your questions.
If you are still debugging, have you thought about using:
Double.TryParse(String, Double);
This will help you in determining what is wrong in each of the string first before you do the actual parsing.
If you have a culture-related problem, you might consider using:
Double.TryParse(String, NumberStyles, IFormatProvider, Double);
This http://msdn.microsoft.com/en-us/library/system.double.tryparse.aspx has a really good example on how to use them.
If you need a long, Int64.TryParse is also available: http://msdn.microsoft.com/en-us/library/system.int64.tryparse.aspx
Hope that helps.
private double ConvertToDouble(string s)
{
char systemSeparator = Thread.CurrentThread.CurrentCulture.NumberFormat.CurrencyDecimalSeparator[0];
double result = 0;
try
{
if (s != null)
if (!s.Contains(","))
result = double.Parse(s, CultureInfo.InvariantCulture);
else
result = Convert.ToDouble(s.Replace(".", systemSeparator.ToString()).Replace(",", systemSeparator.ToString()));
}
catch (Exception e)
{
try
{
result = Convert.ToDouble(s);
}
catch
{
try
{
result = Convert.ToDouble(s.Replace(",", ";").Replace(".", ",").Replace(";", "."));
}
catch {
throw new Exception("Wrong string-to-double format");
}
}
}
return result;
}
and successfully passed tests are:
Debug.Assert(ConvertToDouble("1.000.007") == 1000007.00);
Debug.Assert(ConvertToDouble("1.000.007,00") == 1000007.00);
Debug.Assert(ConvertToDouble("1.000,07") == 1000.07);
Debug.Assert(ConvertToDouble("1,000,007") == 1000007.00);
Debug.Assert(ConvertToDouble("1,000,000.07") == 1000000.07);
Debug.Assert(ConvertToDouble("1,007") == 1.007);
Debug.Assert(ConvertToDouble("1.07") == 1.07);
Debug.Assert(ConvertToDouble("1.007") == 1007.00);
Debug.Assert(ConvertToDouble("1.000.007E-08") == 0.07);
Debug.Assert(ConvertToDouble("1,000,007E-08") == 0.07);
In your string I see: 15.5859949000000662452.23862099999999 which is not a double (it has two decimal points). Perhaps it's just a legitimate input error?
You may also want to figure out if your last String will be empty, and account for that situation.
I'm trying to load some XY-coordinates from a asc-file. It looks like this:
-55.988544 9382
-53.395804 9403
-50.804601 9433
Then I am converting the coordinates to floats. But somehow f.e. for the first value I get "-55988544.0" instead of "-55.988544".
Here is the code:
private void btngettext_Click(object sender, EventArgs e)
{
StreamReader objStream = new StreamReader("C:\\...\\.asc");
firstLine = objStream.ReadLine();
int i = 0;
/*Split String on Tab,
* will separate words*/
string[] words = firstLine.Split('\t');
richTextBox1.Text = words[0];
foreach(string word in words)
{
if(word != "")
{
Console.WriteLine(word); //the value of the string is "-55.988544" here
//value = float.Parse(word); tried both
value = Convert.ToSingle(word); //here the float value is "-55988544.0"
Console.WriteLine(value.ToString());// "-5,598854E+07"
xyArray[0,i] = value;
i++;
}
}
}
Besides, if I would use objStream.ReadToEnd() or .Read(), how could iterate through lines. Read the values in the first line, save them and proceed to the next line.
Thanks in advance,
BC++
It sounds like your application is running under a culture where "." is a thousands separator rather than a decimal separator. If the source file always uses a ".", then it is better to parse with:
float.Parse(word, System.Globalization.CultureInfo.InvariantCulture);
That will ensure that the parse uses a "." no matter what the machine culture is.
It probably is an issue with the culture settings. Try the following:
var culture = System.Globalization.CultureInfo.InvariantCulture;
value = float.Parse(word, culture);
If your data uses a known, fixed notation for decimal separator etc you should not rely on the defaults of the reading PC. Use
value = float.Parse(word, CultureInfo.InvariantCulture);
Usually when I have need to convert currency string (like 1200,55 zł or $1,249) to decimal value I do it like this:
if (currencyString.Contains("zł)) {
decimal value = Decimal.Parse(dataToCheck.Trim(), NumberStyles.Number | NumberStyles.AllowCurrencySymbol);
}
Is there a way to check if string is currency without checking for specific currency?
If you just do the conversion (you should add | NumberStyles.AllowThousands
| NumberStyles.AllowDecimalPoint as well) then if the string contains the wrong currency symbol for the current UI the parse will fail - in this case by raising an exception. It it contains no currency symbol the parse will still work.
You can therefore use TryParse to allow for this and test for failure.
If your input can be any currency you can use this version of TryParse that takes a IFormatProvider as argument with which you can specify the culture-specific parsing information about the string. So if the parse fails for the default UI culture you can loop round each of your supported cultures trying again. When you find the one that works you've got both your number and the type of currency it is (Zloty, US Dollar, Euro, Rouble etc.)
As I understand it's better to do:
decimal value = -1;
if (Decimal.TryParse(dataToCheck.Trim(), NumberStyles.Number |
NumberStyles.AllowCurrencySymbol,currentCulture, out value)
{do something}
See Jeff Atwood description about TryParse. It doesn't throw an exception and extremely faster than Parse in exception cases.
To check if a string is a currency amount that would be used for entering wages - I used this:
public bool TestIfWages(string wages)
{
Regex regex = new Regex(#"^\d*\.?\d?\d?$");
bool y = regex.IsMatch(wages);
return y;
}
You might try searching the string for what you think is a currency symbol, then looking it up in a dictionary to see if it really is a currency symbol. I would just look at the beginning of the string and the end of the string and pick out anything that's not a digit, then that's what you look up. (If there's stuff at both ends then I think you can assume it's not a currency.)
The advantage to this approach is that you only have to scan the string once, and you don't have to test separately for each currency.
Here's an example of what I had in mind, although it could probably use some refinement:
class Program
{
private static ISet<string> _currencySymbols = new HashSet<string>() { "$", "zł", "€", "£" };
private static bool StringIsCurrency(string str)
{
// Scan the beginning of the string until you get to the first digit
for (int i = 0; i < str.Length; i++)
{
if (char.IsDigit(str[i]))
{
if (i == 0)
{
break;
}
else
{
return StringIsCurrencySymbol(str.Substring(0, i).TrimEnd());
}
}
}
// Scan the end of the string until you get to the last digit
for (int i = 0, pos = str.Length - 1; i < str.Length; i++, pos--)
{
if (char.IsDigit(str[pos]))
{
if (i == 0)
{
break;
}
else
{
return StringIsCurrencySymbol(str.Substring(pos + 1, str.Length - pos - 1).TrimStart());
}
}
}
// No currency symbol found
return false;
}
private static bool StringIsCurrencySymbol(string symbol)
{
return _currencySymbols.Contains(symbol);
}
static void Main(string[] args)
{
Test("$1000.00");
Test("500 zł");
Test("987");
Test("book");
Test("20 €");
Test("99£");
}
private static void Test(string testString)
{
Console.WriteLine(testString + ": " + StringIsCurrency(testString));
}
}