如何在 Android 上只允许一次触摸?我不想支持多点触摸,并且如果我的一个手指已经触摸屏幕,我希望我的应用程序放弃其他触摸。这就像在 iOS 上使用专有触摸。
另外,是否有一种方法可以设置允许的触摸数?
谢谢!
编辑:最低目标 API = 8。
如何在 Android 上只允许一次触摸?我不想支持多点触摸,并且如果我的一个手指已经触摸屏幕,我希望我的应用程序放弃其他触摸。这就像在 iOS 上使用专有触摸。
另外,是否有一种方法可以设置允许的触摸数?
谢谢!
编辑:最低目标 API = 8。
您可以通过使用 android:splitMotionEvents="false"
或者 android:windowEnableSplitTouch="false"
来禁用多点触控。
你需要追踪第一个触摸的指针id,并仅使用与该触摸相对应的触摸事件。以下是来自Android官方博客“理解多点触控”的好例子
private static final int INVALID_POINTER_ID = -1;
// The ‘active pointer’ is the one currently moving our object.
private int mActivePointerId = INVALID_POINTER_ID;
// Existing code ...
@Override
public boolean onTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
// Save the ID of this pointer
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
// Find the index of the active pointer and fetch its position
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
mLastTouchX = x;
mLastTouchY = y;
invalidate();
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
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;
}
}
return true;
}