Web API post passes a parameter value that is always null

This problem has been tangled up in my morning, no matter what kind of method of communication, go to the controller, that parameter will never change equal to NULL

Find a lot of solutions on the Internet

The above is from the Internet, the first: to mark the parameter as [Frombody], to become a simple parameter

Second: It is the way to pass the argument.

I just started to try it this way, but ... Still is null, I have been very silent, tangled for a long time.

Finally, continue to surf the Internet to check the information, found that the method is correct, but the above-mentioned way for the $.ajax () there is no effect, the specific reason I also xiao not,

But if you use $.post (), you can get the value in the controller. It's so ...

Finally use the $.post, and then remember in the controller parameter plus [Frombody], as well as the parameter mode, "= Your parameters"

If you know why $.ajax () can't be realized can tell me ha ~

Above.

Web API post passes a parameter value that is always null