我希望我的应用程序能够识别用户在手机屏幕上从右向左滑动。
如何做到这一点?
我希望我的应用程序能够识别用户在手机屏幕上从右向左滑动。
如何做到这一点?
当前回答
我一直在做类似的事情,但仅限于水平滑动
import android.content.Context
import android.view.GestureDetector
import android.view.MotionEvent
import android.view.View
abstract class OnHorizontalSwipeListener(val context: Context) : View.OnTouchListener {
companion object {
const val SWIPE_MIN = 50
const val SWIPE_VELOCITY_MIN = 100
}
private val detector = GestureDetector(context, GestureListener())
override fun onTouch(view: View, event: MotionEvent) = detector.onTouchEvent(event)
abstract fun onRightSwipe()
abstract fun onLeftSwipe()
private inner class GestureListener : GestureDetector.SimpleOnGestureListener() {
override fun onDown(e: MotionEvent) = true
override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float)
: Boolean {
val deltaY = e2.y - e1.y
val deltaX = e2.x - e1.x
if (Math.abs(deltaX) < Math.abs(deltaY)) return false
if (Math.abs(deltaX) < SWIPE_MIN
&& Math.abs(velocityX) < SWIPE_VELOCITY_MIN) return false
if (deltaX > 0) onRightSwipe() else onLeftSwipe()
return true
}
}
}
然后它可以用于视图组件
private fun listenHorizontalSwipe(view: View) {
view.setOnTouchListener(object : OnHorizontalSwipeListener(context!!) {
override fun onRightSwipe() {
Log.d(TAG, "Swipe right")
}
override fun onLeftSwipe() {
Log.d(TAG, "Swipe left")
}
}
)
}
其他回答
你不需要复杂的计算。 这可以通过使用来自GestureDetector类的OnGestureListener接口来完成。
在onFling方法中,你可以像这样检测所有四个方向:
MyGestureListener.java:
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
public class MyGestureListener implements GestureDetector.OnGestureListener{
private static final long VELOCITY_THRESHOLD = 3000;
@Override
public boolean onDown(final MotionEvent e){ return false; }
@Override
public void onShowPress(final MotionEvent e){ }
@Override
public boolean onSingleTapUp(final MotionEvent e){ return false; }
@Override
public boolean onScroll(final MotionEvent e1, final MotionEvent e2, final float distanceX,
final float distanceY){ return false; }
@Override
public void onLongPress(final MotionEvent e){ }
@Override
public boolean onFling(final MotionEvent e1, final MotionEvent e2,
final float velocityX,
final float velocityY){
if(Math.abs(velocityX) < VELOCITY_THRESHOLD
&& Math.abs(velocityY) < VELOCITY_THRESHOLD){
return false;//if the fling is not fast enough then it's just like drag
}
//if velocity in X direction is higher than velocity in Y direction,
//then the fling is horizontal, else->vertical
if(Math.abs(velocityX) > Math.abs(velocityY)){
if(velocityX >= 0){
Log.i("TAG", "swipe right");
}else{//if velocityX is negative, then it's towards left
Log.i("TAG", "swipe left");
}
}else{
if(velocityY >= 0){
Log.i("TAG", "swipe down");
}else{
Log.i("TAG", "swipe up");
}
}
return true;
}
}
用法:
GestureDetector mDetector = new GestureDetector(MainActivity.this, new MyGestureListener());
view.setOnTouchListener(new View.OnTouchListener(){
@Override
public boolean onTouch(final View v, final MotionEvent event){
return mDetector.onTouchEvent(event);
}
});
为了有点击监听器,双击监听器,OnLongPress监听器,向左滑动,向右滑动,向上滑动,在单视图上向下滑动,你需要setOnTouchListener。也就是说,
view.setOnTouchListener(new OnSwipeTouchListener(MainActivity.this) {
@Override
public void onClick() {
super.onClick();
// your on click here
}
@Override
public void onDoubleClick() {
super.onDoubleClick();
// your on onDoubleClick here
}
@Override
public void onLongClick() {
super.onLongClick();
// your on onLongClick here
}
@Override
public void onSwipeUp() {
super.onSwipeUp();
// your swipe up here
}
@Override
public void onSwipeDown() {
super.onSwipeDown();
// your swipe down here.
}
@Override
public void onSwipeLeft() {
super.onSwipeLeft();
// your swipe left here.
}
@Override
public void onSwipeRight() {
super.onSwipeRight();
// your swipe right here.
}
});
}
为此,你需要实现OnTouchListener的OnSwipeTouchListener类。
public class OnSwipeTouchListener implements View.OnTouchListener {
private GestureDetector gestureDetector;
public OnSwipeTouchListener(Context c) {
gestureDetector = new GestureDetector(c, new GestureListener());
}
public boolean onTouch(final View view, final MotionEvent motionEvent) {
return gestureDetector.onTouchEvent(motionEvent);
}
private final class GestureListener extends GestureDetector.SimpleOnGestureListener {
private static final int SWIPE_THRESHOLD = 100;
private static final int SWIPE_VELOCITY_THRESHOLD = 100;
@Override
public boolean onDown(MotionEvent e) {
return true;
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
onClick();
return super.onSingleTapUp(e);
}
@Override
public boolean onDoubleTap(MotionEvent e) {
onDoubleClick();
return super.onDoubleTap(e);
}
@Override
public void onLongPress(MotionEvent e) {
onLongClick();
super.onLongPress(e);
}
// Determines the fling velocity and then fires the appropriate swipe event accordingly
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
boolean result = false;
try {
float diffY = e2.getY() - e1.getY();
float diffX = e2.getX() - e1.getX();
if (Math.abs(diffX) > Math.abs(diffY)) {
if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (diffX > 0) {
onSwipeRight();
} else {
onSwipeLeft();
}
}
} else {
if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
if (diffY > 0) {
onSwipeDown();
} else {
onSwipeUp();
}
}
}
} catch (Exception exception) {
exception.printStackTrace();
}
return result;
}
}
public void onSwipeRight() {
}
public void onSwipeLeft() {
}
public void onSwipeUp() {
}
public void onSwipeDown() {
}
public void onClick() {
}
public void onDoubleClick() {
}
public void onLongClick() {
}
}
If you want to display some buttons with actions when an list item is swipe are a lot of libraries on the internet that have this behavior. I implemented the library that I found on the internet and I am very satisfied. It is very simple to use and very quick. I improved the original library and I added a new click listener for item click. Also I added font awesome library (http://fortawesome.github.io/Font-Awesome/) and now you can simply add a new item title and specify the icon name from font awesome.
这是github的链接
@Edward Brey的方法很有效。如果有人也想复制和粘贴导入的OnSwipeTouchListener,他们是:
import android.content.Context;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
OnSwipeTouchListener.java:
import android.content.Context;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
public class OnSwipeTouchListener implements OnTouchListener {
private final GestureDetector gestureDetector;
public OnSwipeTouchListener (Context ctx){
gestureDetector = new GestureDetector(ctx, new GestureListener());
}
@Override
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
private final class GestureListener extends SimpleOnGestureListener {
private static final int SWIPE_THRESHOLD = 100;
private static final int SWIPE_VELOCITY_THRESHOLD = 100;
@Override
public boolean onDown(MotionEvent e) {
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
boolean result = false;
try {
float diffY = e2.getY() - e1.getY();
float diffX = e2.getX() - e1.getX();
if (Math.abs(diffX) > Math.abs(diffY)) {
if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (diffX > 0) {
onSwipeRight();
} else {
onSwipeLeft();
}
result = true;
}
}
else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
if (diffY > 0) {
onSwipeBottom();
} else {
onSwipeTop();
}
result = true;
}
} catch (Exception exception) {
exception.printStackTrace();
}
return result;
}
}
public void onSwipeRight() {
}
public void onSwipeLeft() {
}
public void onSwipeTop() {
}
public void onSwipeBottom() {
}
}
用法:
imageView.setOnTouchListener(new OnSwipeTouchListener(MyActivity.this) {
public void onSwipeTop() {
Toast.makeText(MyActivity.this, "top", Toast.LENGTH_SHORT).show();
}
public void onSwipeRight() {
Toast.makeText(MyActivity.this, "right", Toast.LENGTH_SHORT).show();
}
public void onSwipeLeft() {
Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();
}
public void onSwipeBottom() {
Toast.makeText(MyActivity.this, "bottom", Toast.LENGTH_SHORT).show();
}
});