Format zero currency value with {0:C} in VB.Net - asp.net

Question

I am trying to format a zero currency value as an empty string, so that when the currency value is 0.00 then an empty string gets displayed rather than $0.00.
This code is part of an ASP.Net app that will display currency value to end user.
I have used following code to achieve this goal.
Question : Is it possible to achieve this by just using {0:C} format string or another version of this format string instead of using if then else coding for this? If I use ###,###,###.## as the data format string then an empty string shows for zero currency value and also I get rid of the if then else coding but for non-zero values no currency symbol shows.
If Double.Parse(Decimal.Parse(CDec(currencyValue))) = 0 Then
charValue = Nothing
Else
charValue = String.Format("{0:C}", CDec(currencyValue))
End If
UPDATE
I ended up using the following code, which is working fine. If is better than IIf because it does short-circuiting, which means that IIf will evaluate all expressions whether the condition is true or false but If will evaluate the first expression only if condition is true and evaluate the second expression only if condition is false.
Dim d As Decimal
Decimal.TryParse(currencyValue, d)
charValue = If(d = 0D, Nothing, String.Format("{0:C}", d))

Answer 1

I don't think there is a way using formatting to display an empty string.
But you can write it like:
charValue = If( currencyValue = 0D, "", currencyValue.ToString("C") )
using the If Operator (Visual Basic).
Also this is something I would not do:
If Double.Parse(Decimal.Parse(CDec(currencyValue))) = 0 Then
If currencyValue is Decimal:
If (currencyValue = 0D) Then
If currencyValue is Double:
If (currencyValue = 0R) Then
Also, if you are using a database and this is a Sql Server mind SQL Server Data Type Mappings

Answer 2

I don't think you can when using C or the other similar standard formats, since they are already defining a culture-specific format that will include a format for zero.
But if you specify your own custom format, you can specify three different formats separated by ;s, one each for positive numbers, negative numbers, and zero, respectively.
For example (giving an empty string for the zero format, resulting in blank zeroes):
charValue = String.Format("{0:#,##0.00;-#,##0.00;""""}", CDec(currencyValue))
And from what I can see, omitting the format for negative gives a default that matches the positive, whereas omitting the format for zero gives blank, which is what you're looking for, so this should be sufficient as well:
charValue = String.Format("{0:#,##0.00;;}", CDec(currencyValue))
(Using whichever custom format you wish.)
UPDATE: You can get the current currency symbol and manually put it into your custom format. IE:
Dim symbol = CultureInfo.CurrentCulture.NumberFormat.CurrencySymbol
charValue = String.Format("{0}{1:#,##0.00;;}", symbol, CDec(currencyValue))
From the sound of it, though, I think I would actually recommend doing basically what you started with, maybe with an extension method.
<Extension>
Public Function ToCurrencyString(pValue As Decimal) As String
Return IIf(pValue = 0, "", pValue.ToString("C"))
End Function
Dim someValue As Decimal = 1.23
Console.WriteLine(someValue.ToCurrencyString())
This gives you exactly what you're looking for. The exact same format as C gives, but with blank zeroes.