所以我得到了这个工作类，它在屏幕中创建一个 DarkHole 对象。它是一个具有随机颜色、位置和半径的实心圆。
public class DarkHole extends View
{
private ShapeDrawable mDarkHole;
// instance variables
private int x, y, Xt, Yt; // position
private double forca; // velocity
private int raio; // radius
private int minRaio = 30;
private int maxRaio = 200;
private WindowManager wm;
private Display display;
private int width;
private int height;
int r,g,b ;
int randomColor;
Point size;
private Random rand;
// constructor
public DarkHole(Context context)
{
super(context);
mDarkHole = new ShapeDrawable(new OvalShape());
rand = new Random();
//Get Screen Size
size = new Point();
wm = (WindowManager)getContext().getSystemService(Context.WINDOW_SERVICE);
display = wm.getDefaultDisplay();
display.getSize(size);
width = (size.x);
height = (size.y);
//Set a random color
r = rand.nextInt(255);
g = rand.nextInt(255);
b = rand.nextInt(255);
randomColor = Color.rgb(r, g, b);
CriarDarkHole();
}
public void CriarDarkHole()
{
x = rand.nextInt(width + 1);
y = rand.nextInt(height + 1);
raio = rand.nextInt(maxRaio - minRaio + 1) + minRaio;
mDarkHole.getPaint().setColor(randomColor);
mDarkHole.setBounds(x, y, x + raio, y + raio);
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
//mDarkHole.draw(canvas);
//for(int i = 0; i <100; i++)
// {
mDarkHole.draw(canvas);
//}
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
Xt = (int) event.getX();
Yt = (int) event.getY();
int evento = event.getAction();
switch (evento)
{
case MotionEvent.ACTION_DOWN:
CriarDarkHole();
//isTouch = true;
break;
case MotionEvent.ACTION_MOVE:
//coords.setText("X: " + X + ", Y: " + Y);
break;
case MotionEvent.ACTION_UP:
//Toast.makeText(this, "Saiu da tela em: X: " + X + ", Y: " + Y, Toast.LENGTH_SHORT);
//isTouch = false;
break;
}
return true;
}
}
我的问题是:
CriarDarkHole() 仅触发一次。每次调用时，它都应该创建另一个黑洞，在屏幕上添加球。在这种情况下，每次触摸屏幕时。
为什么它不起作用？应该怎么做？
编辑 1 - 尝试添加 ShapeDrawable 数组并绘制它
public class DarkHole extends View
{
private ShapeDrawable mDarkHole;
// instance variables
private int x, y, Xt, Yt; // position
private double forca; // velocity
private int raio; // radius
private int minRaio = 30;
private int maxRaio = 200;
List<ShapeDrawable> holescreated;
private WindowManager wm;
private Display display;
private int width;
private int height;
int r,g,b ;
int randomColor;
Point size;
private Random rand;
// constructor
public DarkHole(Context context)
{
super(context);
rand = new Random();
holescreated = new ArrayList<ShapeDrawable>();
//Get Screen Size
size = new Point();
wm = (WindowManager)getContext().getSystemService(Context.WINDOW_SERVICE);
display = wm.getDefaultDisplay();
display.getSize(size);
width = (size.x);
height = (size.y);
CriarDarkHole();
}
public void CriarDarkHole()
{
//mDarkHole = new ShapeDrawable(new OvalShape());
holescreated.add(new ShapeDrawable(new OvalShape()));
//Set a random color
r = rand.nextInt(255);
g = rand.nextInt(255);
b = rand.nextInt(255);
randomColor = Color.rgb(r, g, b);
x = rand.nextInt(width + 1);
y = rand.nextInt(height + 1);
raio = rand.nextInt(maxRaio - minRaio + 1) + minRaio;
for(ShapeDrawable m: holescreated)
{
m.getPaint().setColor(randomColor);
m.setBounds(x, y, x + raio, y + raio);
}
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
//mDarkHole.draw(canvas);
for(ShapeDrawable m: holescreated)
{
m.draw(canvas);
}
invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
Xt = (int) event.getX();
Yt = (int) event.getY();
int evento = event.getAction();
switch (evento)
{
case MotionEvent.ACTION_DOWN:
CriarDarkHole();
//isTouch = true;
break;
case MotionEvent.ACTION_MOVE:
//coords.setText("X: " + X + ", Y: " + Y);
break;
case MotionEvent.ACTION_UP:
//Toast.makeText(this, "Saiu da tela em: X: " + X + ", Y: " + Y, Toast.LENGTH_SHORT);
//isTouch = false;
break;
}
return true;
}
}
现在，当我点击显示屏时，它会绘制一个新球，但会删除旧球。 如何画出所有的球？我哪里失踪了？
<小时/>编辑 2 - 现在可以工作，但感觉编码方式不正确
public class DarkHole extends View
{
private ShapeDrawable mDarkHole;
// instance variables
private int x, y, Xt, Yt; // position
private double forca; // velocity
private int raio; // radius
private int minRaio = 30;
private int maxRaio = 100;
List<ShapeDrawable> holescreated;
private WindowManager wm;
private Display display;
private int width;
private int height;
int r,g,b ,cont;
int randomColor;
Paint cor;;
Point size;
private Random rand;
// constructor
public DarkHole(Context context)
{
super(context);
cor = new Paint();
rand = new Random();
holescreated = new ArrayList<ShapeDrawable>();
cont = 0;
//Get Screen Size
size = new Point();
wm = (WindowManager)getContext().getSystemService(Context.WINDOW_SERVICE);
display = wm.getDefaultDisplay();
display.getSize(size);
width = (size.x);
height = (size.y);
CriarDarkHole();
}
public void CriarDarkHole()
{
cor.setColor(Color.BLACK);
cor.setTextSize(70);
cor.setAntiAlias(true);
cor.setDither(true);
//mDarkHole = new ShapeDrawable(new OvalShape());
holescreated.add(new ShapeDrawable(new OvalShape()));
//Set a random color
r = rand.nextInt(255);
g = rand.nextInt(255);
b = rand.nextInt(255);
randomColor = Color.rgb(r, g, b);
raio = rand.nextInt(maxRaio - minRaio + 1) + minRaio;
x = rand.nextInt((width-raio) + 1) ;
y = rand.nextInt((height-raio) + 1) ;
for(ShapeDrawable m: holescreated)
{
holescreated.get(cont).getPaint().setColor(randomColor);
holescreated.get(cont).setBounds(x, y, x + raio, y + raio);
}
cont++;
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
//mDarkHole.draw(canvas);
for(ShapeDrawable m: holescreated)
{
m.draw(canvas);
canvas.drawText("Bolas: " + holescreated.size(),10,50, cor);
}
invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
Xt = (int) event.getX();
Yt = (int) event.getY();
int evento = event.getAction();
switch (evento)
{
case MotionEvent.ACTION_DOWN:
CriarDarkHole();
//isTouch = true;
break;
case MotionEvent.ACTION_MOVE:
CriarDarkHole();
//coords.setText("X: " + X + ", Y: " + Y);
break;
case MotionEvent.ACTION_UP:
//Toast.makeText(this, "Saiu da tela em: X: " + X + ", Y: " + Y, Toast.LENGTH_SHORT);
//isTouch = false;
break;
}
return true;
}
}
应用图片
<小时/>
即使现在它可以工作，但感觉不是正确的方法。我的意思是，以面向对象的方式......是不是每次都重新绘制所有的球？!有什么提示、批评或建议吗？
最佳答案
像魅力一样工作!
现在我可以在触摸时绘制多个球，甚至可以测试它们的碰撞
public class DarkHole extends View {
public static final int maxDiameter = 250;
public static final int minDiameter = 240;
/**
* This class log tag.
*/
private static final String LOG_TAG = DarkHole.class.getSimpleName();
private static List<ShapeDrawable> mHoles;
private int mWindowWidth;
private int mWindowHeight;
private Random random;
/**
* The constructor;
*
* @param context application context.
*/
public DarkHole(Context context) {
super(context);
mHoles = new ArrayList<ShapeDrawable>();
random = new Random();
//Get Screen Size
Point point = new Point();
WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = windowManager.getDefaultDisplay();
display.getSize(point);
// Get screen max x and y.
mWindowWidth = point.x;
mWindowHeight = point.y;
}
/**
* Draw random hole.
*/
private void generateRandomHole() {
while(true) {
ShapeDrawable hole = new ShapeDrawable(new OvalShape());
// Generate random color.
int r = random.nextInt(255);
int g = random.nextInt(255);
int b = random.nextInt(255);
int randomColor = Color.rgb(r, g, b);
// Generate random position.
int diameter = random.nextInt(maxDiameter - minDiameter + 1) + minDiameter;
int x = random.nextInt((mWindowWidth - diameter) + 1);
int y = random.nextInt((mWindowHeight - diameter) + 1);
hole.getPaint().setColor(randomColor);
hole.setBounds(x, y, x + diameter, y + diameter);
if (checkDrawContains(hole)) {
hole = null;
} else {
mHoles.add(hole);
break;
}
}
}
/**
* Draw informative text.
*
* @param canvas canvas object.
*/
private void generateText(Canvas canvas) {
Paint color = new Paint();
color.setColor(Color.BLACK);
color.setTextSize(70);
color.setAntiAlias(true);
color.setDither(true);
canvas.drawText("Bolas: " + mHoles.size(), 10, 50, color);
}
private boolean checkDrawContains(ShapeDrawable newHole) {
long newCenterX = newHole.getBounds().left + (newHole.getBounds().width()/2);
long newCenterY = newHole.getBounds().top + (newHole.getBounds().height()/2);
for(ShapeDrawable hole: mHoles) {
long centerX = hole.getBounds().left + (hole.getBounds().width()/2);
long centerY = hole.getBounds().top + (hole.getBounds().height()/2);
long x = centerX - newCenterX;
long y = centerY - newCenterY;
long aux = (long) ((Math.pow(Math.abs(x),2)) + (Math.pow(Math.abs(y),2)));
long distance = (long) Math.sqrt(aux);
long sRads = (newHole.getBounds().width()/2) + (hole.getBounds().width()/2);
if(distance <= sRads ) {
return true;
}
}
return false;
}
/** {@inheritDoc} */
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
generateText(canvas);
for (ShapeDrawable hole : mHoles) {
hole.draw(canvas);
}
invalidate();
}
/** {@inheritDoc} */
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
generateRandomHole();
return true;
}
return super.onTouchEvent(event);
}
}
想法是:
生成一个具有随机直径、颜色和位置的圆
测试该圆圈是否与已绘制的任何其他圆圈发生碰撞
如果发生碰撞，则重新生成随机内容，如果没有，则将该圆圈添加到数组列表中
关于java - 绘制多个对象 - Android，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30541880/