Java 语法 >>, &, ?和 :

Question

我不明白>>、&、？ and : 在此程序中的意思是:

case MotionEvent.ACTION_POINTER_UP: {
        // Extract the index of the pointer that left the touch sensor
        final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) 
                >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
        final int pointerId = ev.getPointerId(pointerIndex);
        if (pointerId == mActivePointerId) {
            // This was our active pointer going up. Choose a new
            // active pointer and adjust accordingly.
            final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
            mLastTouchX = ev.getX(newPointerIndex);
            mLastTouchY = ev.getY(newPointerIndex);
            mActivePointerId = ev.getPointerId(newPointerIndex);
        }
        break;

你能帮帮我吗？ Google 不会搜索非字母数字字符...

Answer 1

• Bitwise Shift - >>>
• Bitwise AND - &
• Ternary - ? :