So as I've stated in my question I recently wrote a small program to calculate the amount of bricks needed to build a room, using the following
float result = ((fLenght * fWitdh) * fHeight) * bricksPerMeter;
When Running a test case on both my main computer and a second computer they come up with a different answer
Ex: PC 1 ((15 * 1)* 1.8)* 40 = 1080
PC 2 with the same values produces 600 as the answer
now the error is fixed by changing the decimal symbol on the second computer
I want to know if there is anyway for my code to check if this is the case and attempt to fix it
without me going to each computer and setting it manually
Normally when you launch a .NET application, it takes its default culture settings from the operating system. That is to say that computer configured for German (Germany) would result in the de-de culture being used in the application, and a computer configured for English (United Kingdom) would result in the en-gb culture being used in the application.
With these cultures come things like date format strings, decimal separators, etc. which is where your issue comes from.
A simple solution is to change your code, which is currently:
float.TryParse(value, out fValue) ? fValue : 1f
to use the Invariant Culture:
float.TryParse(value, NumberStyles.Any, CultureInfo.InvariantCulture, out fValue) ? fValue : 1f;
This will then use the invariant culture, whose decimal separator is ., to parse the string to a float.
Note that you'll probably want to enforce a culture when you convert the result back to a string. One way to do this is by passing a culture to the .ToString method:
string resultText = result.ToString(CultureInfo.InvariantCulture);
Console.WriteLine(resultText);
Alternative solution (but not recommended): you could override the default culture for your entire application but that might cause problems for you elsewhere, so I don't recommend this.
Related
Some test code:
string Input = "13.00"
float Output = float.Parse(Input, new CultureInfo("en-US"));
On my PC (Win10 x64, English - US) the value of output is 13.
On another PC (Win10 x64) that I don't have access to where the language is US English but the region is Denmark, the value of Output is 1300.
I've tried to recreate the settings on my PC by swapping comma and decimal point and setting the system locale to Denmark but it always gives a value of 13 for me.
I've tried it on some German Win10 x64 PCs and they also set Output to 13.
I thought the purpose of specifying the culture was to force the use of the comma and decimal point to a specific usage?
Any ideas what I am doing wrong here? Thanks!
Update
Adding the following code:
string Debug = string.Format("{0:0.00}", Output);
results in Debug containing "13.00" on our test PCs (English and German) and "1300,00" on the problem PC.
Update 2
Changing from new CultureInfo("en-US") to CultureInfo.InvariantCulture seems to get the correct output of 13 on the problem PC.
What is the difference between en-US and invariant and why would that only manifest itself on this one example PC that we have seen so far?
I'm trying to get a string formatted float number (e.g. "3.14") from a COM port.
I used Convert.ToSingle() but it threw exception "Input string was not in a correct format" And while debugging, I found that double, float and decimal numbers are separated by '/' instead of '.'; for example 3.14 was 3/14.
My system language is English, but date and time formats are in Persian (Windows 10). In Persian, we use / instead of . as the decimal symbol.(۳/۱۴ = 3.14)
Is there any way to make program independent of system regional settings and force it to always use '.' as decimal symbol?
Using Convert.ToSingle will attempt to convert an object to a floating-point number based on the system's region settings, as you have already noticed.
In order to reliably convert a string that is, for example, in US-English format, you can provide an additional argument of the type IFormatProvider to the method.
string text = "3.5";
IFormatProvider culture = System.Globalization.CultureInfo.GetCultureInfo("en-US");
float number = Convert.ToSingle(text, culture);
The result stored in number be 3.5, i.e. the number halfway between three and four, independent of your system settings. For example, the above code works as expected on my computer, even though it's set to the German (de-DE) region, which represents the same number as 3,5.
See also the documentation of Convert.ToSingle for details.
I have a problem with converting string to double, it works fine when I run it on my local machine but when I deploy it to the server it "cuts" 0 in front.
For example I have a string value of 0,0123 and when I convert it to double I get 123.
I use ASP.NET with C#, method I use is Convert.ToDouble() and the hosting is somee.com.
Right now I just divide the number by 10000 and get what I need, but as you can imagine it's not prefect solution so maybe someone has better idea of how to solve it.
This happens because your machine and the server are using two different cultures.
Some cultures use "." as a decimal point, while others use ",".
It seems that in your server culture, "." is the decimal point - and so the comma in "0,0123" is treated as a thousands separator instead.
I would use the overload for double.TryParse or Convert.ToDouble that takes an IFormatProvider and pass in the correct CultureInfo.
In the future, try using CultureInfo.InvariantCulture to format all your internal data (i.e. data persistence, or data flowing within your system), and use the proper CultureInfo for displaying data to the user.
The decimal point is not the same across cultures and, therefore, computers with different culture setting.
Try using double.Parse(string, CultureInfo) with an explicit CultureInfo that works for your format.
Based on the fact you express your value as 0,0123 rather than 0.0123, I would guess the language/culture settings on the server are different than on your own machine.
Try printing out the result of System.Globalization.CultureInfo.CurrentCulture.Name from somewhere on the server, and compare it to what your local machine produces.
I have written a small program where the program works differently on different operating systems (xp, win7) The problem is the program reads some float numbers such 2,686.
One operating system (win7) convert it to float true, but on xp it goes wrong and print it 2686. How can I understand which symbol the operation system uses for decimal numbers ?
Thanks.
string sep = CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator;
This does not depend on the operating system but at the (default) language settings on each PC.
If you use : double value = double.Parse(text); you are using whatever culture the user has configured. If you know the input to be in a certain format, use:
var ci = CultureInfo.GetCulture("nl-NL"); // dutch
double value = double.Parse(text, ci);
Every function that converts has (1 or more) overloads to take a FormattingProvider (Culture).
parse the floating point numbers using the user current culture with double.Parse(string, System.Globalization.CultureInfo.CurrentCulture);
The decimal separator is decided by the current culture.
If you want to use a specific character as decimal separator, you can create a custom NumberFormatInfo object with any separator you like. If you want to use period as deimcal separator, you can simply use InvariantCulture:
double n = Double.Parse(s, CultureInfo.InvariantCulture);
If you want to use comma, you can choose a culture that has that, for example swedish:
double n = Double.Parse(s, CultureInfo.GetCultureInfo("sv-SE"));
I have a textbox accepting user input; I am trying to use this user input it to populate this member of one of my business objects:
public System.Decimal? ExchangeRate
The application is localized - I need to support at the same time cultures that accept these as valid inputs: "1,5" and "1.5"
The code I have now is:
var culture = Thread.CurrentThread.CurrentUICulture;
int exchangeRate;
int.TryParse(txtExchangeRate.Text, NumberStyles.Number, culture,
out exchangeRate);
entity.ExchangeRate = exchangeRate;
When the user culture is set to a culture that expects the "1,5" format (comma as decimal separator) - e.g "ro-RO", I want the value that gets stored in entity.ExchangeRate to be 1.5; however, when running the code above, it gets converted to 15 instead.
Any suggestions on how to convert these various formats so that the data that gets stored in my business entity is "1.5" (point as decimal separator)?
Thanks.
You guys were right - it made sense to use Thread.CurrentThread.CurrentCulture instead of Thread.CurrentThread.CurrentUICulture and decimal.TryParse instead of int.TryParse.
But these changes would still not solve my problem. And after playing around with the code some more, I can now simplify the issue to this:
I am using a telerik RadNumericTextBox control which enforce users to use the correct format based on their culture. So, when Thread.CurrentThread.CurrentCulture is set to "ro-RO", it will only accept the "1,5" format, and when it's set to "en-GB", it will only accept the "1.5" format.
Here's the code I am using now:
decimal exchangeRate;
decimal.TryParse(txtExchangeRate.Text, out exchangeRate);
entity.ExchangeRate = exchangeRate;
Case 1: current culture is "en-GB" - accepted input is "1.5" , exchangeRate is set to 1.5 - everything works fine.
Case 2: current culture is "ro-RO" - accepted input is "1,5" , but after executing the decimal.TryParse... line, exchangeRate is set to 15 - wrong, obviously.
I should also mention that in this case, the value of txtExchangeRate.Text is also shown as "1.5" in my Watch window.
So, it looks like decimal.TryParse will take into consideration the current culture, but I can't find a way to actually make it work properly for me. Any suggestions?
OK, here's the code that seems to work on both cases I described in my above post (1. culture "ro-RO", comma as decimal separator and 2. culture "en-GB", dot as decimal separator):
decimal exchangeRate;
decimal.TryParse(txtExchangeRate.Text, NumberStyles.Any,
CultureInfo.InvariantCulture, out exchangeRate);
entity.ExchangeRate = exchangeRate;
Obviously, int cannot hold 1.5 ! :-) Use float instead.
Use CurrentCulture instead of CurrentUICulture. My culture is fr-BE (therefore accepts 1,5 but my Windows UI is English, which doesn't).
I would make the float.Parse() test with both CurrentCulture AND InvariantCulture: By the time some programs learned to accept "1,5", everybody was used to type "1.5". There's nothing which bothers me more than Excel requiring me to type 1,5 when I say 1.5 ! Also, here in Belgium, the 1st year government launched the web-based tax declaration, the site forced you to use commas instead of periods as decimal points. Everybody was wondering why the figures entered were refused!
So be nice to your users and accept both.
FYI I know this isn't your problem, but its a pointer for other people who might be doing this:
When you set your culture, you can't have your application be able to handle input of different cultures. It must be of the type that you have specified.
Therefore, if you set ro-RO as the culture, it won't understand both 1.5 and 1,5 as the same thing.
You should probably be using CurrentCulture (as opposed to CurrentUICulture) for localization (e.g. date/number formatting).