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
对@Mirek Rusin的回答做了一点修改,现在你可以检测多点触摸了。这段代码在Kotlin上:
class OnSwipeTouchListener(ctx: Context, val onGesture: (gestureCode: Int) -> Unit) : OnTouchListener {
private val SWIPE_THRESHOLD = 200
private val SWIPE_VELOCITY_THRESHOLD = 200
private val gestureDetector: GestureDetector
var fingersCount = 0
fun resetFingers() {
fingersCount = 0
}
init {
gestureDetector = GestureDetector(ctx, GestureListener())
}
override fun onTouch(v: View, event: MotionEvent): Boolean {
if (event.pointerCount > fingersCount) {
fingersCount = event.pointerCount
}
return gestureDetector.onTouchEvent(event)
}
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 {
var result = false
try {
val diffY = e2.y - e1.y
val diffX = e2.x - e1.x
if (Math.abs(diffX) > Math.abs(diffY)) {
if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (diffX > 0) {
val gesture = when (fingersCount) {
1 -> Gesture.SWIPE_RIGHT
2 -> Gesture.TWO_FINGER_SWIPE_RIGHT
3 -> Gesture.THREE_FINGER_SWIPE_RIGHT
else -> -1
}
if (gesture > 0) {
onGesture.invoke(gesture)
}
} else {
val gesture = when (fingersCount) {
1 -> Gesture.SWIPE_LEFT
2 -> Gesture.TWO_FINGER_SWIPE_LEFT
3 -> Gesture.THREE_FINGER_SWIPE_LEFT
else -> -1
}
if (gesture > 0) {
onGesture.invoke(gesture)
}
}
resetFingers()
}
} else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
if (diffY > 0) {
val gesture = when (fingersCount) {
1 -> Gesture.SWIPE_DOWN
2 -> Gesture.TWO_FINGER_SWIPE_DOWN
3 -> Gesture.THREE_FINGER_SWIPE_DOWN
else -> -1
}
if (gesture > 0) {
onGesture.invoke(gesture)
}
} else {
val gesture = when (fingersCount) {
1 -> Gesture.SWIPE_UP
2 -> Gesture.TWO_FINGER_SWIPE_UP
3 -> Gesture.THREE_FINGER_SWIPE_UP
else -> -1
}
if (gesture > 0) {
onGesture.invoke(gesture)
}
}
resetFingers()
}
result = true
} catch (exception: Exception) {
exception.printStackTrace()
}
return result
}
}}
在姿态。SWIPE_RIGHT和其他是唯一的整数标识符的手势,我用它来检测一种手势在我的活动:
rootView?.setOnTouchListener(OnSwipeTouchListener(this, {
gesture -> log(Gesture.parseName(this, gesture))
}))
这里的gesture是一个整型变量它包含了我之前传递的值。
其他回答
@Mirek Rusin的回答很好。 但是,有一个小bug,需要修复
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) {
if (getOnSwipeListener() != null) {
getOnSwipeListener().onSwipeRight();
}
} else {
if (getOnSwipeListener() != null) {
getOnSwipeListener().onSwipeLeft();
}
}
result = true;
}
}
else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
if (diffY > 0) {
if (getOnSwipeListener() != null) {
getOnSwipeListener().onSwipeBottom();
}
} else {
if (getOnSwipeListener() != null) {
getOnSwipeListener().onSwipeTop();
}
}
result = true;
}
有什么不同?我们设置result = true,仅当我们检查了所有的需求(SWIPE_THRESHOLD和SWIPE_VELOCITY_THRESHOLD都是Ok的)。这是重要的,如果我们放弃滑动,如果一些需求没有实现,我们必须做smth在OnSwipeTouchListener的onTouchEvent方法!
这是一个简单的Android代码,用于检测手势方向
在MainActivity.java和activity_main.xml中编写如下代码:
MainActivity.java
import java.util.ArrayList;
import android.app.Activity;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.GestureOverlayView.OnGesturePerformedListener;
import android.gesture.GestureStroke;
import android.gesture.Prediction;
import android.os.Bundle;
import android.widget.Toast;
public class MainActivity extends Activity implements
OnGesturePerformedListener {
GestureOverlayView gesture;
GestureLibrary lib;
ArrayList<Prediction> prediction;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lib = GestureLibraries.fromRawResource(MainActivity.this,
R.id.gestureOverlayView1);
gesture = (GestureOverlayView) findViewById(R.id.gestureOverlayView1);
gesture.addOnGesturePerformedListener(this);
}
@Override
public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
ArrayList<GestureStroke> strokeList = gesture.getStrokes();
// prediction = lib.recognize(gesture);
float f[] = strokeList.get(0).points;
String str = "";
if (f[0] < f[f.length - 2]) {
str = "Right gesture";
} else if (f[0] > f[f.length - 2]) {
str = "Left gesture";
} else {
str = "no direction";
}
Toast.makeText(getApplicationContext(), str, Toast.LENGTH_LONG).show();
}
}
activity_main.xml
<android.gesture.GestureOverlayView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android1="http://schemas.android.com/apk/res/android"
xmlns:android2="http://schemas.android.com/apk/res/android"
android:id="@+id/gestureOverlayView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android1:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Draw gesture"
android:textAppearance="?android:attr/textAppearanceMedium" />
</android.gesture.GestureOverlayView>
@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;
我知道从2012年开始有点晚了,但我希望它能帮助到一些人,因为我认为它比大多数答案都更短,更干净:
view.setOnTouchListener((v, event) -> {
int action = MotionEventCompat.getActionMasked(event);
switch(action) {
case (MotionEvent.ACTION_DOWN) :
Log.d(DEBUG_TAG,"Action was DOWN");
return true;
case (MotionEvent.ACTION_MOVE) :
Log.d(DEBUG_TAG,"Action was MOVE");
return true;
case (MotionEvent.ACTION_UP) :
Log.d(DEBUG_TAG,"Action was UP");
return true;
case (MotionEvent.ACTION_CANCEL) :
Log.d(DEBUG_TAG,"Action was CANCEL");
return true;
case (MotionEvent.ACTION_OUTSIDE) :
Log.d(DEBUG_TAG,"Movement occurred outside bounds " +
"of current screen element");
return true;
default :
return super.onTouchEvent(event);
}
});
当然,你可以只留下相关的手势。
src: https://developer.android.com/training/gestures/detector
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")
}
}
)
}