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我不能理解爲什麼我在底部的while循環中嵌入的for循環中獲得不兼容的類型。總是收到不兼容的類型錯誤時對其進行編譯,就上不兼容的類型 - 請幫助 - BlueJ BouncingBall演示
bounceBall = ball.get(ⅰ);任何人有什麼想法,我做錯了什麼?
import java.awt.Color;
import java.util.ArrayList;
import java.util.Random;
public class BallDemo
{
private Canvas myCanvas;
private ArrayList ball;
private BouncingBall bounceBall;
private Random randomGenerator;
public BallDemo()
{
myCanvas = new Canvas("Ball Demo", 600,500);
}
public void bounce()
{
int ground = 400;
ball = new ArrayList();
randomGenerator = new Random();
myCanvas.setVisible(true);
myCanvas.erase();
myCanvas.drawLine(50, ground, 550, ground);
BouncingBall ball1 = new BouncingBall(position(), position(), 16, Color.BLUE, ground, myCanvas);
ball1.draw();
BouncingBall ball2 = new BouncingBall(position(), position(), 20, Color.RED, ground, myCanvas);
ball2.draw();
BouncingBall ball3 = new BouncingBall(position(), position(), 20, Color.BLACK, ground, myCanvas);
ball3.draw();
ball.add(ball1);
ball.add(ball2);
ball.add(ball3);
boolean finished = false;
while (!finished)
{
myCanvas.wait(50);
for(int i = 0; i < ball.size(); i++)
{
bounceBall = ball.get(i);
bounceBall.move();
if(bounceBall.getXPosition() >= 550)
{
finished = true;
}
}
}
}
public int position()
{
return randomGenerator.nextInt(200);
}
}
WOW,我知道這是什麼做的語法,我在幹什麼那麼錯了?或者可以請你澄清爲什麼我的語法關閉?你幫了我很多!在BlueJ中,它只是說我沒有輸入正確的類型......有點模糊。 – user3559061
我應該將此推薦給那些更擅長解釋Java泛型與非泛型相關的人,因爲我是該語言的新手,並且我曾編程過的所有代碼都使用泛型(尖括號中包含的類型)。 – Don
好吧,我必須再次感謝您的'通用'知識:D! – user3559061