The world could not be constructed. The world subclass may not have a public constructor without parameters, or may not be public.
All my world subclasses are public, and there are no errors in the code there.
Navique wrote ...
2018/4/11
What does this error mean?
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Navique wrote...
The world could not be constructed. The world subclass may not have a public constructor without parameters, or may not be public.
All my world subclasses are public, and there are no errors in the code there.danpost wrote...
Navique wrote...
The world could not be constructed. The world subclass may not have a public constructor without parameters, or may not be public.
All my world subclasses are public, and there are no errors in the code there.public CalamityBeginning(int score)
{
// Create a new world with 600x400 cells with a cell size of 1x1 pixels.
super(600, 400, 1);
prepare();
counter counter = getCounter();
theCounter = new counter();
addObject(theCounter, 203, 104);
theCounter.setCount(score);
}
/**
* Prepare the world for the start of the program.
* That is: create the initial objects and add them to the world.
*/
private void prepare()
{
Button button = new Button();
addObject (button,308,170);
button.setLocation(305,180);
CreditsButton creditsbutton = new CreditsButton();
addObject(creditsbutton,305,280);
creditsbutton.setLocation(305,250);
}
public counter getCounter()
{
return theCounter;
}Your world constructor has a parameter (line 1).
"The world could not be constructed. The world subclass may not have a public constructor without parameters, or may not be public."
Add the following to the class:
to give the class a constructor without a parameter.
public CalamityBeginning()
{
this(0); // calls your line 1 above
}danpost wrote...
Your world constructor has a parameter (line 1).
"The world could not be constructed. The world subclass may not have a public constructor without parameters, or may not be public."
Add the following to the class:
public CalamityBeginning()
{
this(0); // calls your line 1 above
}Navique wrote...
I've done this, I've been trying to implement a feature to pass on the score between all screens, so that it may be used as currency, or the like. When I switch to another screen and make it go back to CalamityBeginning, it crashes.danpost wrote...
Navique wrote...
I've done this, I've been trying to implement a feature to pass on the score between all screens, so that it may be used as currency, or the like. When I switch to another screen and make it go back to CalamityBeginning, it crashes.public class CalamityBeginning extends World
{
private counter theCounter;
/**
* Constructor for objects of class CalamityBeginning.
*
*/
public CalamityBeginning(int score)
{
// Create a new world with 600x400 cells with a cell size of 1x1 pixels.
super(600, 400, 1);
prepare();
counter counter = getCounter();
theCounter = new counter();
addObject(theCounter, 203, 104);
theCounter.setCount(score);
}
public CalamityBeginning()
{
this(0); // calls your line 1 above
}
/**
* Prepare the world for the start of the program.
* That is: create the initial objects and add them to the world.
*/
private void prepare()
{
Button button = new Button();
addObject (button,308,170);
button.setLocation(305,180);
CreditsButton creditsbutton = new CreditsButton();
addObject(creditsbutton,305,280);
creditsbutton.setLocation(305,250);
}
public counter getCounter()
{
return theCounter;
}
}public class Replay extends Actor
{
/**
* Act - do whatever the Replay wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
public void act()
{
if (Greenfoot.mouseClicked(this)) {
World world;
world = getWorld();
CalamityBeginning calWorld = (CalamityBeginning) getWorld();
counter counter = calWorld.getCounter();
Greenfoot.setWorld(new CalamityBeginning(counter.returnCount()));
}
}
}
danpost wrote...
Show the counter class also, please.public class counter extends Actor
{
/**
* Act - do whatever the counter wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
public void act()
{
}
public int totalCount = 0;
public void bumpCount(int amount)
{
totalCount += amount;
setImage(new GreenfootImage(""+ totalCount, 30, Color.WHITE, Color.BLACK));
}
public int returnCount(){
return totalCount;
}
public void setCount(int amount)
{
setImage(new GreenfootImage(""+ amount, 30, Color.WHITE, Color.BLACK));
}
}Nothing jumps out at me. Post what error message you are getting (copy/paste entire output).
Found something. In the counter class, your setCount method needs the following for its first line:
However, as an alternative, you can remove the setCount method from the counter class and change "setCount" at line 18 in your CalamityBeginning class to "bumpCount".
totalCount = amount;
danpost wrote...
Found something. In the counter class, your setCount method needs the following for its first line:
totalCount = amount;
You lost all connection to the CalamityBeginning class when you went to your Gameover world. So the score cannot be recovered. Show your Gameover class codes.
here it is, keep in mind CalamityBeginning is also a world.
public class Gameover extends World
{
private counter theCounter;
private Replay theButton;
/**
* Constructor for objects of class Gameover.
*
*/
public Gameover(int score)
{
super(600, 400, 1);
prepare();
counter counter = getCounter();
theCounter = new counter();
addObject(theCounter, 203, 104);
theCounter.bumpCount(score);
theButton = new Replay();
addObject(theButton, 290, 225);
}
public void prepare ()
{
}
public counter getCounter()
{
return theCounter;
}
}Okay. Change your Replay codes (what is shown above) to this:
public class Replay extends Actor
{
public void act()
{
if (Greenfoot.mouseClicked(this)) {
Gameover goWorld = (Gameover) getWorld();
counter counter = goWorld .getCounter();
Greenfoot.setWorld(new CalamityBeginning(counter.returnCount()));
}
}
}There are more replies on the next page.
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