java - 创建一个随机圆圈，可以像按钮一样单击，但它是一个圆圈

Question

这个问题已经有答案了:

creating a random circle that can be clicked on like a button (2 个回答)

已关闭 8 年前。

这就是我的困境，我似乎无法在互联网上的任何地方找到它。我的问题很简单。我正在为 Android 创建一个游戏应用程序。游戏将在屏幕上生成用户可以单击的随机圆圈，然后一旦用户单击这些随机圆圈之一，就会发生一项操作。这就像按钮的功能，但有所不同，因为整个圆圈都可以被单击。我将发布生成圆圈的随机数生成器。这不是主类，而是扩展 View 的单独类。我尝试在下面的 onTouchEvent 方法中执行此操作，但现在我在 logcat 中收到错误，我已将这些错误发布在下面以及主类中。我觉得我已经非常接近找到这个问题的解决方案了。如果有人能告诉我我在这个类上做错了什么，那将非常有帮助，谢谢大家

public class DrawingView extends View {



public DrawingView(Context context) {
    super(context);
    // TODO Auto-generated constructor stub

}
RectF rectf = new RectF(0, 0, 200, 0);

private static final int w = 100;
public static int lastColor = Color.BLACK;
private final Random random = new Random();
private final Paint paint = new Paint();
private final int radius = 230;
private final Handler handler = new Handler();
public static int redColor = Color.RED;
public static int greenColor = Color.GREEN;
int randomWidth =(int) (random.nextInt(getWidth()-radius/2) + radius/2f);
int randomHeight = (random.nextInt((int) (getHeight()-radius/2 + radius/2f)));

private final Runnable updateCircle = new Runnable() {
    @Override 
    public void run() {
        lastColor = random.nextInt(2) == 1 ? redColor : greenColor;
        paint.setColor(lastColor);
        invalidate();
        handler.postDelayed(this, 1000);

    }
};



@Override 
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    handler.post(updateCircle);
}

@Override 
protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    handler.removeCallbacks(updateCircle);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    // your other stuff here

    canvas.drawCircle(randomWidth, randomHeight + radius/2f, radius, paint);
}

@Override
public boolean onTouchEvent (MotionEvent event) {

    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN : 
            randomWidth = (int) event.getX();
            randomHeight = (int) event.getY();
            invalidate(); 
            break;
    }

    return true;

}

告诉我这是否可以完成，或者我是否必须完全更改我的代码，谢谢，这是我的主课，如果这有帮助的话，这是我唯一的其他代码，所以这里请忽略我试图自己学习的评论，但每次都失败了

public class Main extends Activity {
    DrawingView v;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);


        LinearLayout layout1 = new LinearLayout (this);
        FrameLayout game = new FrameLayout(this);
        DrawingView v = new DrawingView (this);

        TextView myText = new TextView(this);

        //int w = getResources().getInteger(DrawingView.redColor);
        //Button redCircle = (Button) findViewById(w);



         //redCircle.setWidth(300);
         //redCircle.setText("Start Game");


        layout1.addView(myText);
       // layout1.addView(redCircle); 
        //redCircle.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

        //game.addView(myText);
        game.addView(v);
        game.addView(layout1);
        setContentView(game);
        //redCircle.setOnClickListener((OnClickListener) this);
    }
    public void onClick(View v) {
        Intent intent = new Intent(this, Main.class);
            startActivity(intent);

        // re-starts this activity from game-view. add this.finish(); to remove from stack
   }

    @Override
    public boolean onCreateOptionsMenu(Menu menu){
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

我现在在日志猫中收到这些错误

03-31 01:48:52.594: E/AndroidRuntime(2395): FATAL EXCEPTION: main
03-31 01:48:52.594: E/AndroidRuntime(2395): Process: com.Tripps.thesimplegame, PID: 2395
03-31 01:48:52.594: E/AndroidRuntime(2395): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Tripps.thesimplegame/com.Tripps.thesimplegame.Main}: java.lang.IllegalArgumentException: n <= 0: -115
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.ActivityThread.access$800(ActivityThread.java:144)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.os.Looper.loop(Looper.java:135)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.ActivityThread.main(ActivityThread.java:5221)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at java.lang.reflect.Method.invoke(Native Method)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at java.lang.reflect.Method.invoke(Method.java:372)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
03-31 01:48:52.594: E/AndroidRuntime(2395): Caused by: java.lang.IllegalArgumentException: n <= 0: -115
03-31 01:48:52.594: E/AndroidRuntime(2395):     at java.util.Random.nextInt(Random.java:182)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at com.Tripps.thesimplegame.DrawingView.<init>(DrawingView.java:37)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at com.Tripps.thesimplegame.Main.onCreate(Main.java:30)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.Activity.performCreate(Activity.java:5933)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
03-31 01:48:52.594: E/AndroidRuntime(2395):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
03-31 01:48:52.594: E/AndroidRuntime(2395):     ... 10 more

Answer 1

对于这些行，您在 random.nextInt() 中使用负数，考虑使用 Math.abs() 时必须使用正数

而不是

int randomWidth =(int) (random.nextInt(getWidth()-radius/2) + radius/2f);
int randomHeight = (random.nextInt((int) (getHeight()-radius/2 + radius/2f)));

使用 Math.abs() 这样你就不会给 random.nextInt() 一个负数

int randomWidth =(int) (random.nextInt(Math.abs(getWidth()-radius/2)) + radius/2f);
    int randomHeight = (random.nextInt((int) Math.abs((getHeight()-radius/2 + radius/2f))));