Animating on the Fling event

问题

package com.example.flingtry;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.graphics.drawable.AnimationDrawable;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.View.OnClickListener;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.support.v4.app.NavUtils;

public class MainActivity extends Activity implements OnClickListener 
{
    private static final int SWIPE_MIN_DISTANCE = 10;
    private static final int SWIPE_MAX_OFF_PATH = 50;
    private static final int SWIPE_THRESHOLD_VELOCITY = 10;
    private GestureDetector gestureDetector;
    TextView img;
    AnimationDrawable ribinclickanimation;
    Button btn1;
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        gestureDetector = new GestureDetector(new MyGestureDetector());
        img= (TextView) findViewById(R.id.img);
        img.setBackgroundResource(R.anim.clickframeanimation);
        ribinclickanimation= (AnimationDrawable) img.getBackground();
        btn1= (Button) findViewById(R.id.btn1);
        btn1.setOnClickListener(this);
        // Set the touch listener for the main view to be our custom gesture listener
        img.setOnTouchListener(new View.OnTouchListener() 
        {
            public boolean onTouch(View v, MotionEvent event) 
            {
                if (gestureDetector.onTouchEvent(event)) 
                {
                    return true;
                }
                return false;
            }
        });
    }
    class MyGestureDetector extends SimpleOnGestureListener 
    {
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) 
        {
            if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH && Math.abs(velocityY) > SWIPE_THRESHOLD_VELOCITY) 
            {
                ribinclickanimation.stop();
                Toast.makeText(getApplicationContext(), "Helloooo", Toast.LENGTH_SHORT).show();
                img.setBackgroundResource(R.anim.clickframeanimation);
                ribinclickanimation= (AnimationDrawable) img.getBackground();
                ribinclickanimation.start();
                return false;
            }
            return false;
        }

        // It is necessary to return true from onDown for the onFling event to register
        @Override
        public boolean onDown(MotionEvent e) 
        {
                return true;
        }
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2,float distanceX, float distanceY) 
        {
            // beware, it can scroll to infinity
            return true;
        }
    }
    public void onClick(View arg0) 
    {
        // TODO Auto-generated method stub
        Toast.makeText(getApplicationContext(), "Helloooo", Toast.LENGTH_SHORT).show(); 
    }
}

This code is used for animating image on fling event using Gestures. but the problem here is that it takes time for animation to happen after the drag is done.. what i want is as i drag down the image should animate at the same time .

回答1:

suggestion is use onTouch instead of gesture listner

write cases for MotionEvent.ACTION_DOWN: MotionEvent.ACTION_UP: and MotionEvent.ACTION_MOVE

Once you detect the direction to move in MotionEvent.ACTION_MOVE use view.setTranslationX or view.setTranslationY depending on direction you want .... Rest what you want after certain drag/move you can write in MotionEvent.ACTION_UP with view

This is just instruction google it for sample code loads of code available

来源：https://stackoverflow.com/questions/13008435/animating-on-the-fling-event