我正在制作一个应用程序,并且它可以正常工作,但幸运的是我知道我的问题是什么。我有一个围绕边界移动的精灵,我希望精灵在特定位置射球。目前,我的应用程序在位置 (0,0) 处显示球,然后在应该的时候将其射过去。它通过在更新方法中向 x 添加 10 来实现这一点,因此它是一个动画,我可以通过更改 10 来加快速度以减慢速度。变量 x 和 y 的默认值为 0。我比按照上面指定的方式更改它们。我希望它们默认保持为 0,但我不希望球在移动之前显示。现在它在启动时显示球,然后移动。一旦我给出 x 和 y 值,我希望它显示球。
这是当前代码的片段。
// This moves the ball down the right side of screen
if (x > ov.getWidth() - width - xSpeed){
xSpeed = 0;
ySpeed = 10;
direction = 1;
shootL(); // shoots the ball left towards the left side of screen
}
// moves ball up the screen on left side
if (x + xSpeed < 0){
x = 0;
xSpeed = 0;
ySpeed = -10;
direction = 3;
shootR(); // shoots the ball towards right side of screen
}
private void shootR() {
// TODO Auto-generated method stub
// need to manipulate variable q to go across screen
q += 10;
// eventually manipulate r so that it shoots at the right spot on screen, not my major problem right now.
}
private void shootL() {
// TODO Auto-generated method stub
// need to manipulate variable q to go across screen
q += -10;
// eventually manipulate r so that it shoots at the right spot on screen, not my major problem right now.
}
public void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
update();
int srcY = direction * height;
Rect src = new Rect (0, srcY, width, srcY + height);
Rect dst = new Rect (x, y, x+width, y+height);
canvas.drawBitmap(b, src, dst, null); // draws sprite around border
Paint p = new Paint();
canvas.drawBitmap(fire, q, r, p); // draws ball that shoots across
}
有人有什么想法或建议吗?它只是在错误的时间显示球,我需要解决这个问题。一定是错误什么的。