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
为了添加一个onClick,下面是我所做的。
....
// in OnSwipeTouchListener class
private final class GestureListener extends SimpleOnGestureListener {
.... // normal GestureListener code
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
onClick(); // my method
return super.onSingleTapConfirmed(e);
}
} // end GestureListener class
public void onSwipeRight() {
}
public void onSwipeLeft() {
}
public void onSwipeTop() {
}
public void onSwipeBottom() {
}
public void onClick(){
}
// as normal
@Override
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
} // end OnSwipeTouchListener class
我正在使用Fragments,因此使用getActivity()作为上下文。这就是我实现它的方法——而且它很有效。
myLayout.setOnTouchListener(new OnSwipeTouchListener(getActivity()) {
public void onSwipeTop() {
Toast.makeText(getActivity(), "top", Toast.LENGTH_SHORT).show();
}
public void onSwipeRight() {
Toast.makeText(getActivity(), "right", Toast.LENGTH_SHORT).show();
}
public void onSwipeLeft() {
Toast.makeText(getActivity(), "left", Toast.LENGTH_SHORT).show();
}
public void onSwipeBottom() {
Toast.makeText(getActivity(), "bottom", Toast.LENGTH_SHORT).show();
}
public void onClick(){
Toast.makeText(getActivity(), "clicked", Toast.LENGTH_SHORT).show();
}
});
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);
}
});
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
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
/**
* Detects left and right swipes across a view.
*/
class OnSwipeTouchListener(context: Context, onSwipeCallBack: OnSwipeCallBack?) : OnTouchListener {
private var gestureDetector : GestureDetector
private var onSwipeCallBack: OnSwipeCallBack?=null
init {
gestureDetector = GestureDetector(context, GestureListener())
this.onSwipeCallBack = onSwipeCallBack!!
}
companion object {
private val SWIPE_DISTANCE_THRESHOLD = 100
private val SWIPE_VELOCITY_THRESHOLD = 100
}
/* fun onSwipeLeft() {}
fun onSwipeRight() {}*/
override fun onTouch(v: View, event: MotionEvent): Boolean {
return gestureDetector.onTouchEvent(event)
}
private inner class GestureListener : SimpleOnGestureListener() {
override fun onDown(e: MotionEvent): Boolean {
return true
}
override fun onFling(eve1: MotionEvent?, eve2: MotionEvent?, velocityX: Float, velocityY: Float): Boolean {
try {
if(eve1 != null&& eve2!= null) {
val distanceX = eve2?.x - eve1?.x
val distanceY = eve2?.y - eve1?.y
if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (distanceX > 0)
onSwipeCallBack!!.onSwipeLeftCallback()
else
onSwipeCallBack!!.onSwipeRightCallback()
return true
}
}
}catch (exception:Exception){
exception.printStackTrace()
}
return false
}
}
}
因为这个问题有点老,很流行,我试图更新答案,并通过结合答案和评论中的多种建议来改进它。
从Java切换到Kotlin并使用一些Kotlin语法Eyecandy(主观) 使onswipe函数返回它们是否消耗了事件(ruX答案) 从if语句中移除结果赋值并删除变量(直接返回) 仅检测垂直和水平滑动的替代方案 只能检测上、下、右、左的选择。 为保持一致性(方向,而不是位置),将上下重命名为上下。
四个方向都刷:
open class OnSwipeTouchListener(val context: Context?) : OnTouchListener {
companion object {
private const val SwipeThreshold = 100
private const val SwipeVelocityThreshold = 100
}
private val gestureDetector = GestureDetector(context, GestureListener())
override fun onTouch(v: View, event: MotionEvent): Boolean {
return gestureDetector.onTouchEvent(event)
}
open fun onSwipeRight(): Boolean { return false }
open fun onSwipeLeft(): Boolean { return false }
open fun onSwipeUp(): Boolean { return false }
open fun onSwipeDown(): Boolean { return false }
private inner class GestureListener : SimpleOnGestureListener() {
override fun onDown(e: MotionEvent): Boolean {
return true
}
override fun onFling(
e1: MotionEvent,
e2: MotionEvent,
velocityX: Float,
velocityY: Float,
): Boolean {
try {
val diffY = e2.y - e1.y
val diffX = e2.x - e1.x
if (abs(diffX) > abs(diffY)) {
if (abs(diffX) > SwipeThreshold && abs(velocityX) > SwipeVelocityThreshold) {
return when {
diffX > 0 -> onSwipeRight()
else -> onSwipeLeft()
}
}
} else if (abs(diffY) > SwipeThreshold && abs(velocityY) > SwipeVelocityThreshold) {
return when {
diffY > 0 -> onSwipeDown()
else -> onSwipeUp()
}
}
} catch (exception: Exception) {
exception.printStackTrace()
}
return false
}
}
}
用法:
myView.setOnTouchListener(object : OnSwipeTouchListener(context) {
// Implement any function you need:
override fun onSwipeUp(): Boolean {
Toast.makeText(context, "UP", Toast.LENGTH_SHORT).show()
return true
}
override fun onSwipeLeft(): Boolean {
Toast.makeText(context, "LEFT", Toast.LENGTH_SHORT).show()
return true
}
})
onFling()的替代方案
替代方案删除更多代码并重新排序检查。重新排序是没有必要的,但我认为它看起来更整洁,更容易理解。 代码将放在try括号中。用法保持不变,只是实现各自的onSwipe函数
水平
val diffY = e2。Y - e1。Y 返回if (abs(velocityY) > SwipeVelocityThreshold) { 当{ > SwipeThreshold -> onSwipeDown() diffY < - swipethreshold -> onSwipeUp() Else -> false } }其他false
垂直
val diffX = e2。X - e1。X 返回if (abs(velocityX) > SwipeVelocityThreshold) { 当{ > SwipeThreshold -> onSwipeRight() diffX < - swipethreshold -> onSwipeLeft() Else -> false } }其他false
一个方向
"up"的例子
val diffY = e2。Y - e1。Y 返回{ diffY < - swipethreshold -> onSwipeUp() Else -> false }
Additional Notes: In (ruX answer) they discussed removing onDown to also detect an onClickListener for the same view. However, when I removed onDown, the class did not work anymore. I don't exactly know why. I looked into the code of GestureDetector but it is very complex and the consequences of the return value of onDown seems to have some implications. So I left it in. Also, you can just use SimpleOnGestureListener.onSingleTapUp() just like you did onFling and create a onClick() function that is called there.
版本信息:
compileSdkVersion 31 minSdkVersion 24 targetSdkVersion 31
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")
}
}
)
}