Android Studio-如何将onFling应用于imageView？

Question

I'm pretty new to developing apps, so at the moment I'm just trying to learn the basics.

So far my code runs and if I swipe the screen the image moves (which is what I want). However, at the moment the image moves if I swipe anywhere on the screen, but I only want it to move when I swipe the image.

Here's my Main Activity code:

package com.colourdrop.swipeattempt;

import android.os.Bundle;
import android.support.v4.view.GestureDetectorCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.GestureDetector;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;


public class MyActivity extends AppCompatActivity implements
        GestureDetector.OnGestureListener,GestureDetector.OnDoubleTapListener{

    private TextView text;
    private ImageView image;
    private GestureDetectorCompat gestureDetector;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        text = (TextView) findViewById(R.id.textView);
        image = (ImageView) findViewById(R.id.image);
        this.gestureDetector = new GestureDetectorCompat(this, this);
        gestureDetector.setOnDoubleTapListener(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }


    public void update(View v){
        text.setText("You pressed the button!");
    }

    ////// BEGIN GESTURES //////
    @Override
    public boolean onSingleTapConfirmed(MotionEvent e) {
        text.setText("onSingleTapConfirmed");
        return true;
    }

    @Override
    public boolean onDoubleTap(MotionEvent e) {
        text.setText("onDoubleTap");
        return true;
    }

    @Override
    public boolean onDoubleTapEvent(MotionEvent e) {
        text.setText("onDoubleTapEvent");
        return true;
    }

    @Override
    public boolean onDown(MotionEvent e) {
        text.setText("onDown");
        return true;
    }

    @Override
    public void onShowPress(MotionEvent e) {
        text.setText("onShowPress");

    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        text.setText("onSingleTapUp");
        return false;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        text.setText("onScroll");
        return false;
    }

    @Override
    public void onLongPress(MotionEvent e) {
        text.setText("onLongPress");
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        text.setText("onFling");
        image.setX(image.getX()+200);

        return false;
    }


    @Override
    public boolean onTouchEvent(MotionEvent event) {
        this.gestureDetector.onTouchEvent(event);
        return super.onTouchEvent(event);
    }
}

Answer 1

Instead of delegating the Activity's onTouchEvent to the GestureDetector , simply delegate your imageView's onTouch .

image.setOnTouchListener(new View.OnTouchListener() {
    public boolean onTouch(View v, MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
    }
});