Creating a DateTime Parameter That is Optional: A Guide

To avoid the repetitive parameter code, you can opt for Solution 1 where you assign the datasource first and then use SetParameterValue UPDATE1. Alternatively, for Solution 3, you can make the nullable parameter and convert it to datetime if no input is provided by using the code “c# get current date” or “c# datetime current”. Keep in mind that failing to do so will result in the error “Missing parameter values.


Solution 1:

An alternative solution is to allocate them in the following manner.

public DateTime GetDate(DateTime? start = null, DateTime? end = null){
    start = start ?? DateTime.MinValue;
    end = end ?? DateTime.MinValue;
    Console.WriteLine ("start: " + start);
    Console.WriteLine ("end: " + end);
    return DateTime.UtcNow;
}

Which can be used like this:

void Main()
{
    new Test().GetDate();
    new Test().GetDate(start: DateTime.UtcNow);
    new Test().GetDate(end: DateTime.UtcNow);
    new Test().GetDate(DateTime.UtcNow, DateTime.UtcNow);
}

And works just as expected:

start: 1/01/0001 0:00:00
end: 1/01/0001 0:00:00
start: 8/08/2014 17:30:29
end: 1/01/0001 0:00:00
start: 1/01/0001 0:00:00
end: 8/08/2014 17:30:29
start: 8/08/2014 17:30:29
end: 8/08/2014 17:30:29

Take note of the designated parameter utilized to differentiate the value of

start

from

end

.



Solution 2:


By the way, it’s not necessary to use a nullable datetime as suggested by the other answers. Achieving the same result is possible with the following code snippet:

DateTime

.

public DateTime GetDate(
     DateTime start = default(DateTime), 
     DateTime end = default(DateTime))
{
     start = start == default(DateTime) ? DateTime.MinValue : start;
     end = end == default(DateTime) ? DateTime.MinValue : end;
}

It is improbable, but using the default datetime value as an argument for your function will not produce the desired outcome.


Solution 3:


It’s possible to allow

DateTime

to be null and then transform it to

DateTime.Min

in case there is no input parameter.

public DateTime GetDate(DateTime? start = null, DateTime? end = null) {
    var actualStart = start ?? DateTime.Min;
    var actualEnd = end ?? DateTime.Min;
}

Frequently Asked Questions

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