Frustrating problem with my game...

[Greenskull]

I'm currently designing a rhythm game called BeatWave and I've run into a really stupid problem. I have this line of code: player.Power += 1; and it's in one class but whenever I put it in the other class the game breaks and gives me an unhandled exception. I learn by modifying code so this will help me greatly. Please assist me! Thanks.

[TheZMan]

Amazingly enough the answer is going to be exaclty the same in here as it was over on the XNA boards: http://forums.xna.com/62123/ShowThread.aspx#62123

Its almost impossible to help with such vague questions when its obvious you don't have a basic grasp of programming. Please take everyone's advice and write and learn some basic c# programs to learn how to do this. Even if we could answer this one I am sure the next time you randomly move a line of code and get a compiler error you won't understand why.

I'll recommend you back to the learning c# FAQ we sent you to originally http://forums.xna.com/thread/16573.aspx

[Greenskull]

I do have at least a basic understanding of c#. The point is I've tried all the logical things to make it work to no avail.

[TheZMan]

Then you are going to have to find a way of expplainign exactly what you are doing and exactly the error message so that people can help you. The questions you are asking can only be answered by a psychic.

e.g. Try asking this in a car forums:
I pulled a random wire out of my car and now it makes a strange noise what is wrong?

[jsedlak]

You do not have a basic understanding of C#. You have a basic understanding of what the equal sign does in C#.

The reason you cannot just move a line like that is because code is context sensitive. The entire reason this line of code worked in the first place is because in its original place, the code had access to an object named player (probably of type Player or something similar). When you take the line out of this place and move it to another file, you are removing it from the context and thus that object no longer is available to modify. You have to somehow pass the reference to the new place.


Your best bet to answering this problem is to buy a C# book and learn Object Oriented Programming. It is near impossible to learn how to program just by modifying someone else's game.

[MarcusMaximus]

My guess would be(if you get the exception on that line) that Player is null, you haven't initialized it in the new class.

[MarcusMaximus]

on another note: come on guys, just tell him to post his code and tell you where to look or something, it should be obvious the guy is trying to learn.

[TheZMan]

He was asked for more information in the XNA forums (follow the link in my post) and I've suggested that he needs to provide more in here... for some reason he appears to prefer that we make guesses.

We know he's trying to learn but he's not giving enough information.

[SimReality]

Originally Posted by MarcusMaximus

on another note: come on guys, just tell him to post his code and tell you where to look or something, it should be obvious the guy is trying to learn.

If he really wanted to learn, he would go to one of the thousands of C# tutorials online (like suggested above) or get a book. From these short posts it just looks like he wants to mash code around and have other people solve any of his problems. It does him no good for me (or anyone else) to just fix his code for him. If he wants to become a game programmer, he has to learn the language first and then, secondly, learn how to debug that code. I'm not trying to be mean (and I know neither are the other MVPs above), but there is no gain for anyone by us just solving all of these trivial* problems. We are trying to help him become better by actually taking things slowly and learning one step at a time.

*These are trivial because if the OP spent a few days/weeks learning C# he would be able to solve these himself in a matter of minutes.

[LedZepp]

I had that problem and I fixed it by making the variable static. But i dont know if it will help him. Like everyone else is saying you need to provide more information about the problem(what is the error saying exactly) and even posting your whole code will help

[jsedlak]

Originally Posted by LedZepp

I had that problem and I fixed it by making the variable static. But i dont know if it will help him. Like everyone else is saying you need to provide more information about the problem(what is the error saying exactly) and even posting your whole code will help

Generally a baaaaaaaaad idea just to make something like that static.

This is exactly why you should take the time to learn C#.

[LedZepp]

Well for me i had everything in my class file static and made the stupid mistake of just declaring the variable without the static keyword, thats why i said it probably wont work for him.

[Nurta]

Yeah, posting code and context is a good idea when asking for help.

My guess based on name is that what you should have is something like:

in the Player class have a method increasePower(int amount)

and in the other class, if you are given p as the current Player, do p.increasePower(1).

I'm guessing power is a private variable and hence you get issues.

[Greenskull]

ok links found out the problem but doesn't know how to fix it. Apparently, when placed into the other class, player is null. How do i change that?

[Nurta]

um, you have to define player somewhere...

Again, without your code we have no clue what you are doing...

[The Undead]

I think i have an idea of what your problem is, and a possible way to fix it.

You have one class that has player in it, and you want to be able to use player in another class.

So using my experience in java(yes I know its not C# but the languages are alike)
you would have to do this in the class were player is null like this:

PlayerObject player;
public void setPlayer(PlayerObject newPlayer)
{
    player = newPlayer;
}

And in the class that already has player defined or assigned as you will
you call it like this

brokenClass.setPlayer(player)

Again this is all speculation, and some of this may be wrong because 1) you didnt provide much info, and 2) I havent programmed in a while, so im a little rusty.

[Greenskull]

ok so heres where the exception is thrown:

public override void Update(GameTime gameTime)
{
if ((position.Y >= Game.Window.ClientBounds.Height) ||
(position.X >= Game.Window.ClientBounds.Width) ||
(position.X <= -15))
{
MediaPlayer.Stop();
PutinStartPosition();
***** player.Power += 1; *****


}

Where i put stars is the exception

[Nurta]

Well, is player a variable throughout the entire class? If so you probably forgot to initialize it in initialize()

[Link9228]

Hey guys, thanks for the help. I'm really close to getting all the kinks out. And those of you up top, you don't have to be so negative towards people. Yes it's helpful to post what your code is when you are having problems, but it doesn't necessarily mean we are retarded people who don't know how to program and we are trying to get everyone else to do the work for us. This is the only problem we have had, and the program's almost done

[Tiptup300]

It's perfectly alright to learn a language by messing around with a person's app. It's how i learned all the languages I learned. But when you give no real description on what the problem is is where people get irritated. Was player as initilized. Like are there any player = new Player(); or anything like that?