如果您正在寻找像 ImageView.setOnGestureListener 这样的方法,则没有。你可以去看看Android源代码。您最好的选择是在 View 对象的 onTouch() 中处理它。
这是我能做的最简单的 GestureDetector。
我有一个名为 GenesMotionDetector.java 的类。这是它的代码:
package gene.com.motioneventssample;
import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class GenesMotionDetector extends Activity implements GestureDetector.OnGestureListener {
private GestureDetector gestureScanner;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.nothing);
gestureScanner= new GestureDetector(getBaseContext(),this);
}
@Override
public boolean onTouchEvent(MotionEvent me) {
System.out.println("Inside onTouchEvent() of GenesMotionDetector.java");
return gestureScanner.onTouchEvent(me);
}
@Override
public boolean onDown(MotionEvent e) {
System.out.println("Inside onDown() of GenesMotionDetector.java");
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
System.out.println("Inside onFling() of GenesMotionDetector.java");
return true;
}
@Override
public void onLongPress(MotionEvent e) {
System.out.println("Inside onLongPress() of GenesMotionDetector.java");
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
System.out.println("Inside onScroll() of GenesMotionDetector.java");
return true;
}
@Override
public void onShowPress(MotionEvent e) {
System.out.println("Inside onShowPress() of GenesMotionDetector.java");
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
System.out.println("Inside onSingleTapUp() of GenesMotionDetector.java");
return true;
}
}
该类对应的 XML 布局文件是 nothing.xml。这是它的代码:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/screen"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/text"
android:background="#17528c"
android:text="testing"
android:layout_width="100dp"
android:layout_height="200dp" />
<ImageView
android:id="@+id/image"
android:background="#f8af20"
android:layout_width="100dp"
android:layout_height="200dp" />
</LinearLayout>
现在,采用我可以(从上面)制作的最简单的 GestureDetector 并根据您的需要对其进行修改,我得到了:
package gene.com.motioneventssample;
import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.widget.ImageView;
public class GenesMotionDetector3 extends Activity implements GestureDetector.OnGestureListener {
private GestureDetector gestureScanner;
ImageView mView3;
View.OnTouchListener gestureListener;
MotionEvent initialME, finalME;
private VelocityTracker mVelocityTracker = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.nothing);
mView3 = (ImageView) findViewById(R.id.image);
// Gesture detection
gestureScanner = new GestureDetector(getBaseContext(), this);
gestureListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
initialME= event;
if(mVelocityTracker == null) {
// Retrieve a new VelocityTracker object to watch the velocity of a motion.
mVelocityTracker = VelocityTracker.obtain();
}
else {
// Reset the velocity tracker back to its initial state.
mVelocityTracker.clear();
}
// Add a user's movement to the tracker.
mVelocityTracker.addMovement(event);
break;
case MotionEvent.ACTION_MOVE:
mVelocityTracker.addMovement(event);
// When you want to determine the velocity, call
// computeCurrentVelocity(). Then call getXVelocity()
// and getYVelocity() to retrieve the velocity for each pointer ID.
mVelocityTracker.computeCurrentVelocity(1000);
break;
case MotionEvent.ACTION_UP:
finalME=event;
break;
case MotionEvent.ACTION_CANCEL:
// Return a VelocityTracker object back to be re-used by others.
mVelocityTracker.recycle();
break;
}
return onFling(initialME, finalME, mVelocityTracker.getXVelocity(), mVelocityTracker.getYVelocity());
//return false;
}
};
mView3.setOnTouchListener(gestureListener);
}
@Override
public boolean onTouchEvent(MotionEvent me) {
System.out.println("Inside onTouchEvent() of GenesMotionDetector.java");
return gestureScanner.onTouchEvent(me);
}
@Override
public boolean onDown(MotionEvent e) {
System.out.println("Inside onDown() of GenesMotionDetector.java");
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
System.out.println("Inside onFling() of GenesMotionDetector.java");
System.out.println("e1= "+ e1);
System.out.println("e2= "+ e2);
System.out.println("velocityX= "+ velocityX);
System.out.println("velocityY= "+ velocityY);
return true;
}
@Override
public void onLongPress(MotionEvent e) {
System.out.println("Inside onLongPress() of GenesMotionDetector.java");
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
System.out.println("Inside onScroll() of GenesMotionDetector.java");
return true;
}
@Override
public void onShowPress(MotionEvent e) {
System.out.println("Inside onShowPress() of GenesMotionDetector.java");
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
System.out.println("Inside onSingleTapUp() of GenesMotionDetector.java");
return true;
}
}
你还不如在 onTouch() 中处理所有事情。我基本上是在 onTouch 中获取手势并将其传递给 onFling()。