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
这段代码检测左右滑动，避免了废弃的API调用，并对之前的答案进行了其他改进。
/**
* Detects left and right swipes across a view.
*/
public class OnSwipeTouchListener implements OnTouchListener {
private final GestureDetector gestureDetector;
public OnSwipeTouchListener(Context context) {
gestureDetector = new GestureDetector(context, new GestureListener());
}
public void onSwipeLeft() {
}
public void onSwipeRight() {
}
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
private final class GestureListener extends SimpleOnGestureListener {
private static final int SWIPE_DISTANCE_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) {
float distanceX = e2.getX() - e1.getX();
float distanceY = e2.getY() - e1.getY();
if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (distanceX > 0)
onSwipeRight();
else
onSwipeLeft();
return true;
}
return false;
}
}
}
像这样使用它:
view.setOnTouchListener(new OnSwipeTouchListener(context) {
@Override
public void onSwipeLeft() {
// Whatever
}
});
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
}
}
}
我的解决方案与上述类似，但我将手势处理抽象为一个抽象类OnGestureRegisterListener.java，其中包括滑动、单击和长按手势。
OnGestureRegisterListener.java
public abstract class OnGestureRegisterListener implements View.OnTouchListener {
private final GestureDetector gestureDetector;
private View view;
public OnGestureRegisterListener(Context context) {
gestureDetector = new GestureDetector(context, new GestureListener());
}
@Override
public boolean onTouch(View view, MotionEvent event) {
this.view = view;
return gestureDetector.onTouchEvent(event);
}
public abstract void onSwipeRight(View view);
public abstract void onSwipeLeft(View view);
public abstract void onSwipeBottom(View view);
public abstract void onSwipeTop(View view);
public abstract void onClick(View view);
public abstract boolean onLongClick(View view);
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 void onLongPress(MotionEvent e) {
onLongClick(view);
super.onLongPress(e);
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
onClick(view);
return super.onSingleTapUp(e);
}
@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(view);
} else {
onSwipeLeft(view);
}
result = true;
}
}
else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
if (diffY > 0) {
onSwipeBottom(view);
} else {
onSwipeTop(view);
}
result = true;
}
} catch (Exception exception) {
exception.printStackTrace();
}
return result;
}
}
}
像这样使用它。注意，您还可以轻松地传入您的View参数。
OnGestureRegisterListener onGestureRegisterListener = new OnGestureRegisterListener(this) {
public void onSwipeRight(View view) {
// Do something
}
public void onSwipeLeft(View view) {
// Do something
}
public void onSwipeBottom(View view) {
// Do something
}
public void onSwipeTop(View view) {
// Do something
}
public void onClick(View view) {
// Do something
}
public boolean onLongClick(View view) {
// Do something
return true;
}
};
Button button = findViewById(R.id.my_button);
button.setOnTouchListener(onGestureRegisterListener);
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();
}
});
使用SwipeListView，让它为你处理手势检测。
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