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Parsing Text from a Masked Text Box

I have a WinForms application written in C#
I have until recently many textboxes on my forms where the user inputs financial amounts. I have not incorporated any form of mask initially and whenever I need to work with the values input by the users I would Parse the text from each box into Decimal values with Decimal.Parse;
However I have been asked to make the textboxes look like financial amounts
i.e. £1,050.75 rather than 1050.75
I therefore started to change the textboxes into MaskedTextBox and gave them a Mask of £#,##0.00
However now each attempt to Parse the text from the MaskedTextBoxes gives an error 'Input string not in the correct format'.
How do I obtain the users input from the MaskedTextBox and parse into decimal format to work with?
Should I be using MaskedTextBox at all, or is there another way of showing a financial type formatting on the form, without effecting the Decimal.Parse method?

When you are getting the value from Maskedtextbox, it is taking the value as £#,##0.00 . so the symbol will not be converted to decimal. Try to remove the symbol and convert the value to decimal. like
string val= maskedTextBox1.Text.Replace("£","");
Decimal.Parse(val);

You can use a format option with AllowCurrencySymbol. It has to match the currency symbol of the culture. This code I converted from VB so I hope it's correct.
Application.CurrentCulture = New Globalization.CultureInfo("en-GB");
Decimal.Parse("£12,345.67", Globalization.NumberStyles.AllowThousands | Globalization.NumberStyles.AllowDecimalPoint | Globalization.NumberStyles.AllowCurrencySymbol);
Also, see this question if you don't want to change the culture:
Problem parsing currency text to decimal type

You can check MaskFull to see if text is properly enter and then apply anti-mask (by removing that, what your mask is adding).
Unfortunately, I am not aware about automated unmasking. But you can do something like:
if(maskedTextBox1.Mask)
{
var enteredText = maskedTextBox1.SubString(1).Replace(",", null); // remove pound symbol and commas
// ... parse as with normal TextBox
}

How to validate a decimal number to have precision exactly one?

I need to validate user input into a textbox to be a decimal number of precision exactly one? For example below are some of the cases..
if user inputs 1 then it's invalid
if user inputs 0 then its invalid
if user inputs 1.0 then its valid
if user inputs 1.1 then its valid
if user inputs 1.11 then its invalid
if user inputs 100.1 then its valid
How can I achieve this using C#(.net 3.5)?
Its a WPF textbox.
Thanks,
-Mike

For a non-regex way of achieving this:
string input;
decimal deci;
if (input.Length >=3 && input[input.Length - 2].Equals('.') && Decimal.TryParse(input , out deci))
{
// Success
}
else
{
// Fail
}

Easiest way, to me, seems to be to use regular expressions. By interpreting the user input as a string, you can compare it with something like '[0-9]+\.[0-9]'

Yes regular expression is the best way to check your condition:
For exactly NNNN.N (1234.5) use:
/^\d{4}\.\d$/
For optional .N (1234 1234. 1234.5) go with:
/^\d{4}(\.\d?)?$/
For numbers up to size of NNNN.N (1 .5 12.5 123. 1234 1234.5) go with:
/^(?=.*\d)\d{0,4}(\.\d?)?$/
And if you want to allow +/- at the beginning, then replace ^ with ^[-+]?.

C# MVC String Format Zero Values

I currently use this to format my numbers.
#string.Format("£{0:#,###,###.##}", 1000) outputs £1,000
However when I enter a zero value it does this:
#string.Format("£{0:#,###,###.##}", 0.0) outputs £
How do i make this output even when i enter zero values? e.g £0.0
Thanks

The # character means "only use a digit when you need to".
I suspect you want:
#string.Format("£{0:#,###,##0.##}", value)
However, it would generally be a better idea just to use:
#string.Format("{0:c}", value)
... and let the .NET framework do the right thing.

The first 0 is the placeholder, means the first parameter. 00 is an actual format.
For example it could be like this:
Console.WriteLine(string.Format("£{0:#,###,##0.##}", 0));

Formatting currency in .NET

I am formatting the currency using Tostring() method i m using following syntax
ToString('##.##') it is working perfectly but in case of round number it remove last 2 zero
like for 100 it does not show 100.00 is shows 100.
how can i format in that way means
input desired output
100 100.00
100.10 100.10

Try "##.00" instead.
That will force two digits after the decimal separator.
You can also use ToString("C") to use the culture specific format in Windows directly.

First google result.
String.Format("{0:C}", x.ToString());
http://www.howtogeek.com/howto/programming/format-a-string-as-currency-in-c/

You can use :
.ToString("C")
Hope it helps.

Also, if you don't want the currency sign ($ in the US) added that "C" gives, you can also use "F2", which is "fixed number with 2 decimal places". It also has the advantage of giving you a thousands separator when you results go over 1,000.00.

This might help. Might be more than you need, but it takes globalization into account which might be necessary. "C" is also a short-cut currency format string that might get you further along.

How to specify total number of character in C# number formatting?

Is there a way to specify total number of characters when formatting doubles?
Lets say I have 0.00012345678, and I specify total number of characters (7), I want to get 1.23e-4. Format "G7" would give 1.2345e-4.
More examples:
0.00000012345678F -> 1.23e-7
0.00012345678F -> 1.23e-4
0.12345678F -> 1.23e-1
1.2345678F -> 1.23457
12.345678F -> 12.3457
12345678F -> 1.234e8

You probably want to use the "e" format string like so...
String.Format("{0:0.00e+0}", number);

You have a misunderstanding about the meaning of "precision". For a floating point number, "precision" means the number of significant digits, so the result returned by "G6" is correct.
If you want a fixed number of characters, use a custom format string like Jason suggested.

{0:00e+0}
http://blog.stevex.net/string-formatting-in-csharp/