csharp.md

C#

• clock to inject datetime

Types

string

// escape verbatim string
@"this ""word"" is escaped";

// Compare two string arrays
_client.Setup(c => c.Organizations.GetAllByExternalIdsAsync(
    It.Is<string[]>(s => s.SequenceEqual(new[] { "123" })), 
    It.IsAny<PagerParameters>()))
    .Returns(Task.FromResult((IPagination<Organization>)new OrganizationsResponse
    {
        Organizations = new List<Organization>(),
        Count = 0
    }));

decimal

Convert.ToDecimal(123456789012345500.12D)

enum

// to parse enum
public static T To<T>(this string value) where T : struct
{
    return Enum.Parse<T>(value, true);
}

// to store enum as string in db
[JsonConverter(typeof(StringEnumConverter))]
public enum FilterType
{
    BrandName,
    RestaurantIds,
    Postcode
}

clock to inject datetime

public static class Clock
{
    public static Func<DateTime> Now = () => DateTime.Now;
    public static Func<DateTime> UtcNow = () => DateTime.UtcNow;
    public static Func<DateTime> Today = () => DateTime.Today;

    public static void SetNow(Func<DateTime> func)
    {
        Now = func;
    }

    public static void SetUtcNow(Func<DateTime> func)
    {
        UtcNow = func;
    }

    public static void Reset()
    {
        Now = () => DateTime.Now;
        UtcNow = () => DateTime.UtcNow;
        Today = () => DateTime.Today;

    }
}

DateTime

// DateTimeOffset offset exception
// Set Unspecified kind

var input = DateTime.SpecifyKind(dateTime, DateTimeKind.Unspecified);

if (tenant == Tenant.Dk)
    return new LocalDateTime(new DateTimeOffset(input, TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time").GetUtcOffset(input)));

return new LocalDateTime(new DateTimeOffset(input, TimeZoneInfo.FindSystemTimeZoneById("GMT Standard Time").GetUtcOffset(input)));

// Convert Unix Epoch time to DateTime
public DateTime FromUnixTime(long unixTime)
{
    var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
    return epoch.AddSeconds(unixTime);
}

// Convert to UK Time from UTC
public static DateTime ToUkDateTime(this DateTime dateTime)
{
    var zone = TimeZoneInfo.FindSystemTimeZoneById("GMT Standard Time");
    return TimeZoneInfo.ConvertTimeFromUtc(dateTime, zone);

// To ISO String
DateTime.UtcNow.ToString("s", CultureInfo.InvariantCulture)

// Compare Time of the day
var time = DateTime.UtcNow.ToUkDateTime().TimeOfDay;
var lunchStart = new TimeSpan(11, 30, 0);
var lunchEnd = new TimeSpan(14, 30, 0);
var dinnerStart = new TimeSpan(17, 30, 0);
var dinnerEnd = new TimeSpan(22, 30, 0);

if (time >= lunchStart && time <= lunchEnd) return open;
if (time >= dinnerStart && time <= dinnerEnd) return open;

// To ISO String upto milliseconds
public static string ToIsoMilliseconds(this DateTime dateTime)
{
    return dateTime.ToString("yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture);
}

// Precision time to log elapsed time
var watch = Stopwatch.StartNew();
durationInSeconds = watch.Elapsed.Seconds

Delegate

// Get name of Action / Func delegate**
public async Task<T1> LogAndExecute<T1>(string number, Func<Task<T1>> func)
{

    Logger.LogInfo(new Info
    {
        Number = number,
        Method = func.Method.Name,
        LogType = "Pre",
        Message = $"Started calling {func.Method.Name}"
    }.ToJson());

Linq

//Distinct
IEnumerable<Customer> filteredList = originalList
  .GroupBy(customer => customer.CustomerId)
  .Select(group => group.First());

post string value

var client = new HttpClient();
client.SetBearerToken(tokenResponse.AccessToken);
var url = "api endpoint";
var response = client.PostAsync(url, new FormUrlEncodedContent(new KeyValuePair<string, string>[0])).Result;

Turn C# object into a JSON string

var open = new JavaScriptSerializer().Serialize(new {open = true});

Check if an object can be cast to a type

var timestampable = entry.Entity as ITimestampable;
if (timestampable == null)
    continue;

String

Custom Numeric Format Strings

https://msdn.microsoft.com/en-us/library/0c899ak8(v=vs.110).aspx