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How to convert this UTC datetime string to DateTime object c#

I have been trying to convert this string to a DateTime object in C#
2019-09-23T08:34:00UTC+1
I've tried using DateTime.Parse but it is throwing an exception for
"String was not recognized as a valid DateTime."

I'm sorry but you seem like a victim of garbage in, garbage out.
That's an unusual format, that's why before I suggest a solution for you, first thing I want to say is "Fix your input first if you can".
Let's say you can't fix your input, then you need to consider a few things;
First of all, if your string has some parts like UTC and/or GMT, there is no custom date and time format specifier to parse them. That's why you need to escape them as a string literal. See this question for more details.
Second, your +1 part looks like a UTC Offset value. The "z" custom format specifier is what you need for parse it but be careful, this format specifier is not recommended for use with DateTime values since it doesn't reflect the value of an instance's Kind property.
As a solution for DateTime, you can parse it like I would suggest;
var s = "2019-09-23T08:34:00UTC+1";
DateTime dt;
if(DateTime.TryParseExact(s, "yyyy-MM-dd'T'HH:mm:ss'UTC'z", CultureInfo.InvariantCulture,
DateTimeStyles.AdjustToUniversal, out dt))
{
Console.WriteLine(dt);
}
which gives you 2019-09-23 07:34:00 as a DateTime and which has Utc as a Kind property.
As a solution for DateTimeOffset - since your string has a UTC Offset value you should consider to parse with this rather than Datetime
-, as Matt commented, you can use it's .DateTime property to get it's data like;
var s = "2019-09-23T08:34:00UTC+1";
DateTimeOffset dto;
if(DateTimeOffset.TryParseExact(s, "yyyy-MM-dd'T'HH:mm:ss'UTC'z", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dto))
{
Console.WriteLine(dto.DateTime);
}
which gives you the same result DateTime but Unspecified as a .Kind property.
But, again, I strongly suggest you to fix your input first.

Use TryParseExact to convert the string to datetime. Here is the sample code to covert the given format(s) to datetime
private static DateTime ParseDate(string providedDate) {
DateTime validDate;
string[] formats = {
"yyyy-MM-ddTHH:mm:ss"
};
var dateFormatIsValid = DateTime.TryParseExact(
providedDate, formats, CultureInfo.InvariantCulture, DateTimeStyles.None, out validDate);
return dateFormatIsValid ? validDate: DateTime.MinValue;
}
Then, use this function to convert the string. I am replacing UTC+1 to empty string
static void Main(string[] args) {
string strdatetime = "2019-09-23T08:34:00UTC+1";
DateTime dateTime = ParseDate(strdatetime.Replace("UTC+1", ""));
Console.WriteLine(dateTime);
}

How to determine if a value is a valid datetime format or not

I tried parse string values like 2019-04-30T06:46:31.811:00 to a DateTime with DateTime.ParseExact(). No one pattern that I used doesn't fit.
I came to a conclusion that :00 in the end of datetime string this is not valid and expected pattern, that will be represent time zone should be like +05 or +05:00
Some variant of patterns that I used:
"yyyy-MM-dd'T'HH:mm:ss.fffz"
"yyyy-MM-dd'T'HH:mm:ss.fffK"
"yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff':'z"
"yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff':'zz"
"yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff':'Z"
"yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff':'K"
"yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff':'ss"
"yyyy-MM-dd'T'HH:mm:ss.fff:zz"
"yyyy-MM-ddTHH:mm:ss.fff:zz"
"yyyy-MM-dd'T'HH:mm:ss.fff:zz"
"yyyy-MM-ddTHH:mm:ss.fff:zz"

I use this format (2012-09-30T23:00:00.0000000Z) And Its Work , You Can Convert this string To this format and Try this:
var date = DateTime.ParseExact("2012-09-30T23:00:00.0000000Z",
"yyyy-MM-dd'T'HH:mm:ss.fffffff'Z'",
CultureInfo.InvariantCulture,
DateTimeStyles.AssumeUniversal |
DateTimeStyles.AdjustToUniversal);
Console.WriteLine(date);

String Date To convert DateTime using ParseExact

I have a string and it comes as a DD/MM/YYYY style.(eg : 11/07/2018)
I need to convert this To DateTime format and YYYY-MM-DD style.
I tried it using DateTime.Parse but can't
if (!String.IsNullOrEmpty(fromDate))
{
frm = DateTime.ParseExact(fromDate, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None);
}
else if(!String.IsNullOrEmpty(toDate))
{
todt = DateTime.ParseExact(toDate, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None);
}

You can do this in one line of code.
var newDateString = DateTime.ParseExact(myDateString, "dd/MM/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None).ToString("yyyy-MM-dd");
Keep in mind that a DateTime instance is a data structure that does not have a format. When dealing with dates and times it is best to only revert to a human readable string when you need to present/output the value for a human to read. For anything else including persistence to a storage system that supports types (like a relational database) leave the value as a DateTime type.
Example: If you wanted yyyy-MM-dd because you wanted to persist this to Sql Server then you should stop after the parsing (and not call ToString). You can then assign the DateTime instance to a command parameter's Value property directly.

Convert using ParseExact and then use ToString to the target format:
string dateS = "30/04/2018";
DateTime dateD = DateTime.ParseExact(dateS, "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);
string dateS2 = dateD.ToString("yyyy-MM-dd");
Here is a working example in fiddle: https://dotnetfiddle.net/e0yuZ6

How do I create a DateTime object given UTC time and date?

I have date and time strings already in UTC. I need to use those strings to create a DateTime object.
This is the code I'm using. The problem is the time gets converted and my UTC time on the datetime object is no longer correct. I'm giving UTC values so they shouldn't get converted again.
string format = $"{dateFormat}_{timeFormat}";
string value = $"{dateValue}_{timeValue}";
var x = DateTimeOffset.ParseExact(value, format, CultureInfo.CurrentCulture).UtcDateTime;
where dateFormat = "ddMMyy", timeFormat = "HHmmss", dateValue = "191194" and timeValue = "225446".

D Stanley's answer certainly works, but is slightly more complex than you need - if you want a DateTime as the result, you don't need to use DateTimeOffset at all, as DateTime.ParseExact handles DateTimeStyles.AssumeUniversal as well, although you need to specify AdjustToUniversal so that the result is in UTC. (Otherwise it's adjusted to the local time zone automatically - and unhelpfully, IMO, but that's a battle for another day.)
var x = DateTime.ParseExact(
value,
format,
CultureInfo.CurrentCulture,
DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal);
Sample code (that revealed to me the need for DateTimeStyles.AdjustToUniversal):
using System;
using System.Globalization;
class Test
{
static void Main(string[] args)
{
string text = "2015-06-10 20:52:13";
string format = "yyyy-MM-dd HH:mm:ss";
var dateTime = DateTime.ParseExact(
text,
format,
CultureInfo.InvariantCulture,
DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal);
Console.WriteLine(dateTime); // 10/06/2015 20:52:13 on my box
Console.WriteLine(dateTime.Kind); // Utc
}
}
I'd be careful using CultureInfo.CurrentCulture, by the way - bare in mind the fact that it can affect the calendar system in use as well as format strings etc.
(As a side-note of course, I'd recommend using my Noda Time library instead. In this case I'd probably suggest parsing your time using a LocalTimeFormat, your date using a LocalDateFormat, then adding the results together to get a LocalDateTime that you could then convert to a ZonedDateTime using UTC. Or you could use your existing approach to create a ZonedDateTimePattern or InstantPattern, of course.)

Use the overload of DateTimeOffset.ParseExact that takes a DateTimeStyles value:
var x = DateTimeOffset.ParseExact(value,
format,
CultureInfo.CurrentCulture,
DateTimeStyles.AssumeUniversal)
.UtcDateTime;
Note that the call to UtcDateTime doesn't hurt anything, but the time will already be in UTC time (which is what you want) so it will give you back the equivalent DateTime value. You can just use DateTime.ParseExact as Jon suggests, which has the same overload.

This solution also will be helpful if you have your date not as one string.
Just use DateTimeKind.Utc as constructor parameter of DateTime:
new DateTime(2020, 05, 07, 18, 33, 0, DateTimeKind.Utc);

Convert 2015-06-01T02:31:00+0000 to DateTime object c#

I'm writting an app that consume this webservice:
http://finance.yahoo.com/webservice/v1/symbols/allcurrencies/quote?format=json
as you can see there, the JSON object comes with an utc datetime field. I want to save this information in a simple DateTime object with the following format "yyyy-MM-dd HH:mm:ss".
This is my code:
DateTime dateParsed = DateTime.Now;
DateTime.TryParseExact((string)resource.SelectToken("resource").SelectToken("fields")["utctime"], "yyyy'-'MM'-'dd'T'HH':'mm':'ssz", CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.AdjustToUniversal, out dateParsed);
I'm getting an DateTime object initialized in the year 0001.
What I'm doing wrong?

You should be using the K custom format specifier (instead of z).
string s = "2015-06-01T04:41:10+0000";
DateTime dt = DateTime.ParseExact(s, "yyyy-MM-dd'T'HH:mm:ssK",
CultureInfo.InvariantCulture,
DateTimeStyles.AdjustToUniversal);
It will read the +0000 as the offset. Then by using the AdjustToUniversal style, the resulting DateTime will also be in terms of Universal time, having DateTimeKind.Utc.
Also, since you're reading from a known data source, there's no real benefit of using TryParseExact. The format from your data source is fixed, so just use ParseExact with that format. The Try... methods are primarily for validating user input, or when the source format could vary.
One last point - if you just parse your data using JSON.net, that format should automatically be recognized. You just use a DateTime or DateTimeOffset property, and it would parse it without issue.

You have just an error in your Format-String. This is a working sample:
using System;
using System.Globalization;
public class Program
{
public static void Main()
{
DateTime dateParsed = DateTime.Now;
if ( DateTime.TryParseExact( "2015-06-01T02:31:00+0000", "yyyy-MM-ddThh:mm:ss+0000", CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.AdjustToUniversal, out dateParsed ) ) {
Console.WriteLine(string.Format("Parsing done: {0:MM/dd/yyyy # hh:mm}", dateParsed ) );
} else {
Console.WriteLine("No result");
}
}
}
Note: the +0000 is hardcoded, when you get other values you would need to detect them. If the api returns only +0 values, you could cut them off and work without z.