Android多点触摸支持
我想知道Android多点触摸支持是否可靠?我读到它有一些问题 我还想知道,如何定义自定义多点触控手势?例如:3个手指旋转或3个手指静止,第四个手指移动 我在developer.android.com上遇到过一些资源手势或MotionEvent,但没有明确说明 问候,Android多点触摸支持,android,multi-touch,Android,Multi Touch,我想知道Android多点触摸支持是否可靠?我读到它有一些问题 我还想知道,如何定义自定义多点触控手势?例如:3个手指旋转或3个手指静止,第四个手指移动 我在developer.android.com上遇到过一些资源手势或MotionEvent,但没有明确说明 问候, Zdenek我在API中进行了深入研究,找到了一种执行捏/反向捏等手势的方法,因此我相信您描述的手势是可能的——只需要弄清楚如何编写它们。下面我粘贴了一个我实现的反向挤压示例。我希望只有在水平方向的情况下,夹点才能注册。它不是非常
Zdenek我在API中进行了深入研究,找到了一种执行捏/反向捏等手势的方法,因此我相信您描述的手势是可能的——只需要弄清楚如何编写它们。下面我粘贴了一个我实现的反向挤压示例。我希望只有在水平方向的情况下,夹点才能注册。它不是非常干净或可重用的代码,但它应该可以帮助您向前迈进。它在安卓2.0.x上运行。我读过multi-touch在早期版本中可能存在问题。该示例是我从活动的onTouchEvent中调用的一个类,将事件转发给该类
public class HorizontalReversePinchDetector {
public boolean onTouchEvent(MotionEvent e) {
int pointerCount = e.getPointerCount();
if(pointerCount != 2) {
Log.d(GESTURE, "not pinching - exactly 2 fingers are needed but have " + pointerCount);
clearPinch();
return false;
}
int firstIndex = e.getX(0) < e.getX(1) ? 0: 1;
int secondIndex = e.getX(0) < e.getX(1) ? 1: 0;
Finger currentLeftFinger = new Finger(e.getX(firstIndex), e.getY(firstIndex));
Finger currentRightFinger = new Finger(e.getX(secondIndex), e.getY(secondIndex));
float yDifference = Math.abs(currentLeftFinger.getY() - currentRightFinger.getY());
if(yDifference > 80) {
Log.d(GESTURE, "not pinching - fingers too vertically-oriented");
clearPinch();
return false;
}
if(initialLeftFinger == null) {
initialLeftFinger = currentLeftFinger;
initialRightFinger = currentRightFinger;
Log.d(GESTURE, "not pinching, but might be starting a pinch...");
return false;
}
float leftFingerDistance = initialLeftFinger.getX() - currentLeftFinger.getX();
float rightFingerDistance = currentRightFinger.getX() - initialRightFinger.getX();
float xDistanceBetweenFingers = Math.abs(currentLeftFinger.getX() - currentRightFinger.getX());
if(xDistanceBetweenFingers < minimumDistanceBetweenFingers) {
Log.d(GESTURE, "pinching, but fingers are not far enough apart...");
return true;
}
if(leftFingerDistance < minimumDistanceForEachFinger) {
Log.d(GESTURE, "pinching, but left finger has not moved enough...");
return true;
}
if(rightFingerDistance < minimumDistanceForEachFinger) {
Log.d(GESTURE, "pinching, but right finger has not moved enough...");
return true;
}
pinchCompleted();
return true;
}
private void pinchCompleted() {
Log.d(GESTURE, "pinch completed");
if(pinchListener != null) pinchListener.onPinch();
clearPinch();
}
public static interface OnPinchListener {
void onPinch();
}
private void clearPinch() {
initialLeftFinger = null;
initialRightFinger = null;
}
public void setPinchListener(OnPinchListener pinchListener) {
this.pinchListener = pinchListener;
}
private static class Finger {
private Finger(float x, float y) {
this.x = x;
this.y = y;
}
public float getX() {
return x;
}
public float getY() {
return y;
}
private float x;
private float y;
}
private Finger initialLeftFinger;
private Finger initialRightFinger;
private OnPinchListener pinchListener;
private static final float minimumDistanceForEachFinger = 30;
private static final float minimumDistanceBetweenFingers = 50;
}
关于可靠性,本规范是完全可靠的。同样,仅在Android 2.0.x上。我没有在平台的其他版本上测试过它。太好了!谢谢你的回复,这正是我一直在寻找的东西。