koobas.hobune.stream
How to Skip Parameter in C#
Hello everyone, I need some information about function parameters in C#. Here is my situation: I have a singleton script called SubtitleManager. This script has a lot of other classes that are inherited from this, and has 1 main function to print subtitles to the screen. Most of the subtitles are the voices of the main character, but there are some other character's subtitles. I want these character's subtitles to be in different color than the main character's. Since I have one main function to print subtitles, I used parameters.
protected void BypassSubtitle(string text, float duration, bool differentColor, Color newColor)
As you can see, we have a boolean variable, script changes the color of the subtitle to newColor variable, or default Color.white variable according to that boolean.
My question is, in some scripts, when I don't want to change the subtitle color, I do not want to pass the last 2 parameters while calling the function. When I write:
BypassSubtitle("blabla", 3.0f);
I get errors that say the function can't take two parameters, as it is obvious that I have 4 parameters so I have to do:
BypassSubtitle("blabla", 3.0f, false, Color.white);
So over here, eventhough I won't be changing the color to another color, I still have to pass any Color parameter for the function to work, I am curious, can this cause overheads? Because actually I have 7-8 parameters, which are situation dependant, and also I have AudioManager which uses parameters too. So I though passing unnecessary parameters can cause performance issues, but I don't know how not to call the function without the parameters that won't be used. Any ideas? Thanks :)
There are a couple of ways you can do this.
Default parameters:
protected void BypassSubtitle(
string text, float duration,
bool differentColor = false, Color newColor = Color.white);
// edit: it turns out that you can't use Color.white or any of the other color
// properties because they aren't constants that can be determined at compile time,
// so you must use the default keyword instead...
// the difference is that the default color will be black instead of white
protected void BypassSubtitle(
string text, float duration,
bool differentColor = false, Color newColor = default(Color));
Specifying the default value allows you to not pass the parameter.
Another way is to overload the method. You start with the one that takes all of the parameters, and in your overload you call that one, passing in defaults for the values that you don't have...
// function with all the params
protected void BypassSubtitle(string text, float duration, bool differentColor, Color newColor)
// function with some of them
protected void BypassSubtitle(string text, float duration)
{
BypassSubtitle(text, duration, false, Color.white);
}
protected void BypassSubtitle(string text)
{
BypassSubtitle(text, 1.5f, true, Color.green);
}
If you go with the overloading, each overload must have a unique call signature, meaning it must be a unique combination of data types/parameter order.
Well I'd like to go with writing default parameters, that sounds really convenient but when I try it, I have this error :
The expression being assigned to optional parameter "newColor" must be a constant or a default value.
Seems like there is no problem with the boolean but something wrong with the Color.white being default?
Hmm, I guess this is what Color.white looks like...
public static Color white
{
get
{
return new Color(1f, 1f, 1f, 1f);
}
}
So it's not a compile time constant.
You can also use the default keyword when declaring the method...
protected void BypassSubtitle(
string text, float duration,
bool differentColor = false, Color newColor = default(Color));
But the color will be black then since the default is all 0s.
Really simply, I'm using the following check:
if (Physics.Linecast(transform.position, player.transform.position))
{
canHitPlayer = true;
}
else
{
canHitPlayer = false;
}
But I also want to tell it to check the queryTriggerInteraction part of the function so it checks the triggers of any objects too, this is the last of the four parameters, while basically ignoring the third parameter, the layer mask, that I don't care about because I don't want to ignore/set any layers.
How would I write it to do that?
Physics.Linecast(transform.position, player.transform.position, queryTriggerInteraction: QueryTriggerInteraction.Collide)
That's co$$anonymous$$g up with a squiggly error line under the Lincast word in Visual Studio, and when I mouse over it, it says "No overload for method 'Linecast' takes 3 arguments."
Ideas?
Sorry, that didn't work, let me try again:
public Class YourClass {
protected void BypassSubtitle(string text, float duration, Color newColor)
{
//Code1
}
protected void BypassSubtitle(string text, float duration)
{
//Code2
}
//then you can just do
BypassSubtitle ("Text", 1.2f, color.red);/* (this will execute Code1 with the Parameters)*/
//or
BypassSubtitle ("Text", 1.2f);/*(this will execute code2) /*
}
You pass in you Code at Code1 and Code2 and it will decide which code to execute based on the Amount and Type of Parameter you've give into it. You can in Theory have infinite of those Methods with the same name but other Parameters. (This is called Overloading a Method) Hope this helps, its my first post :D
