tryparse

is there some way of return null if it can't parse a string to int? with: public .... , string? categoryID) { int.TryParse(categoryID, out categoryID); getting "cannot convert from 'out string' to 'out int' what to do? EDIT: No longer relevant because of asp.net constraints is the way to solve problem /M First of all, why are you trying to parse a string to an int and stick the result back into a string? The method signature is bool int.TryParse(string, out int) so you have to give a variable of type int as second argument. This also means that you won't get null if parsing fails, instead the

When I tried to convert something like 0.1 (from user in textbox), My value b is always false. bool b = Decimal.TryParse("0.1", out value); How can it be here to work? Too late to the party, but I was going to suggest forcing the culuture to en-US but Invariant is a better sln decimal value; bool b = Decimal.TryParse("0.1", NumberStyles.Any, new CultureInfo("en-US"), out value); Specify the culture for the parsing. Your current culture uses some different number format, probably 0,1 . This will successfully parse the string: bool b = Decimal.TryParse("0.1", NumberStyles.Any, CultureInfo

I am attempting to tryparse using decimal; however, I keep getting an "Object Required" run-time error. I'm not certain what I'm doing wrong. I'm used to doing a tryparse in C#. This is VBA, so the language translation is not clicking just yet. Any help appreciated. Sub try() Dim val As Variant Dim res As Boolean res = Decimal.TryParse("2.5", val) MsgBox (res & ":" & val) End Sub You can try CInt and check for a specific error using On Error Goto. res = cBool(Val("2.5")) should do the trick here, since any value <> 0 will evaluate as True 来源： https://stackoverflow.com/questions/23655251

I need to convert the string "Fri Sep 11 00:00:00 GMT+04:00 2020" into a DateTime object 11.09.2011 . When I use DateTime result; DateTime.TryParseExact(MyString, "ddd MMM dd HH:mm:ss 'GMT'zzz yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out result); result is equal to {9/10/2020 11:00:00 PM} . How can I modify the code so that the date component is 11.09.2011 and not 10.09.2011 (I only need the date and don't care about the time) ? Parse into a DateTimeOffset instead, given that you've got an offset. From the documentation of the zz specifier that you're using: With DateTime

How to (try)parse a single String to DateTime in "DD/MM/YYYY" format? (VB.Net) For example: I use input string "30/12/1999" (30 December 1999), how to (try)parse it to DateTime? Try this: Dim date As Datetime = DateTime.ParseExact(_ yourString, "dd/MM/yyyy", CultureInfo.InvariantCulture) This will throw an exception if yourString does not match the format you specify. If you do not want an exception in this case then do this: Dim date As Date Date.TryParseExact(dateString, "dd/MM/yyyy", CultureInfo.CurrentCulture, _ DateTimeStyles.None, date) 来源： https://stackoverflow.com/questions/2794305/how