Using c#, How can I take benefit of using nullable valuetypes when I have a variable of object type? -


Using C #, I can take advantage of a variable type of object when using null value values ?

For example, I have a method that takes 4 arguments: 

  public int update (int32 serial, object delivery date, object quantity, object changes Time) {.... .... ....}

As you can guess, this method contains a new record in the table Table (Table 1) There are 4 columns: Serial Int, Delivery That Datetime Free, Quantity Float Faucet and Softtime SmallNet Empty

Now, May Received concession is: I can take advantage of how to use the tap value-type and I do can change Dettaim like my desirable types I object?

Thank you

Why are your criteria of type object in the first place? Why is it not: 

  public int update (int serial, datetime? Delivery date, double? Quantity, less? Change time)

(note That decimals can be a better option than double .)

If you can possibly change your signature, then you probably know how to get it.

Otherwise, what are you really asking in your question? If you can change not parameters, but type arguments DateTime (or null), double (or null) and Small (or null) then you can put them on your faucet equivalent. Non-empty values ​​for that type of zero value, and non-empty values, will be unboxed null : 

  object x = 10; Int? Y = (int?) X; // y = zero-zero value 10 x = faucet; Y = (int?) X; // y tapable & lt; Int & gt; Edit

Type: You have a text box for shift time, three options Are: it is full but inappropriate (eg "foo"), it is empty, or it is valid. You want to do something like this: 

  small? ShiftTime = Faucet; String User Input = shiftTimeInput.Text; If (userInput.Length> gt; 0) // user has * entered * some * in small value; If (short.TryParse (user input, out value)) {shiftTime = value; } Else {// Invalid to handle input // whatever you want} // Now shiftTime is either empty if the user has left it blank, or call the update method that is passing in the correct value // shiftTime.

Comments

Post a Comment

Popular posts from this blog

sql - dynamically varied number of conditions in the 'where' statement using LINQ -

I am using my first project LINQ (in mvc), so maybe there's something very simple that I remember. However, a day of searching and experimenting does not work, so it works. I am trying to write a LINQ query (Linux to SQL) in which in many cases where the statement is different from an OR or an AND. We do not know how many conditions are going in the query till runtime. This search is for filter control, where the user can choose multiple criteria for filtering. Select from table where table.col = 1 or table.col = 2 or table.col = 7 .... 'Other number of conditions Before I just create the SQL query as a string, while looping over all the situations. However, it seems that there should be a good way to do this in LINQ. I tried to use Expression trees, but they had a second thought for this moment on my head, where the lambda function was to be executed inside the statement such as: values ​​for matchingRows = matchingRows for each value Where (function (row) row.c...
Read more

asp.net mvc - Dynamically Generated Ajax.BeginForm -

I have a problem with ASP.NET MVC Ajax forms. I generate many Ajax form in a table such as: & Lt; Input type = "submit" name = "activity" value = "add activity" / & gt; & Lt;%}% & gt; & Lt; / TD & gt; & Lt; / TR & gt; & Lt;%}% & gt; So far so good. When I post one of those forms, it gives a partial view in a div, and in this new partial view a new Ajax Beginnform (which is not in Genesis form) This second Ajax Beginnorf is exactly like the ones I got on the table, but when I post it, I do not get the "Ajax Post", but a normal post that sends me to a new page, I do not know whether the two Ajax forms What is the reason for the difference between, why is it the "dynamically generated" Ajax form behaves like a normal HTML form? By the way, I know that I can do it in different ways using javascript, but I would like to understand whether it can only be done using MVC helplars and Ajax lib...
Read more

Debug on symbian -

I am using trk for phone debug This works well for the Holorld project But when I start the project in phone debug mode 1) the load failed 2) TrkProtocolPlugin: to target the specified file Failure (please verify If any body understands what problem I am experiencing, then this problem helps me Pre-release If the application has the privileges assigned (with the appropriate certificate) itemprop = "text" > In your case, I will check: / li> If there is no conflict of application ID with any other application of device If there are problematic commands in the installation package (for example copy copy for non-accessible directories)
Read more