Android监听ScrollView滑动到顶端和底部

Android监听ScrollView滑动到顶端和底部

package cn.testscrollview;

import android.os.Bundle;

import android.view.MotionEvent;

import android.view.View;

import android.view.View.OnTouchListener;

import android.widget.ScrollView;

import android.app.Activity;

/**

 * Demo描述:

 * 监听ScrollView滑动到顶端和底部

 *

 * 注意事项:

 * 1 mScrollView.getChildAt(0).getMeasuredHeight()表示:

 *   ScrollView所占的高度.即ScrollView内容的高度.常常有一

 *   部分内容要滑动后才可见,这部分的高度也包含在了

 *   mScrollView.getChildAt(0).getMeasuredHeight()中

 *  

 * 2 view.getScrollY表示:

 *   ScrollView顶端已经滑出去的高度

 *  

 * 3 view.getHeight()表示:

 *   ScrollView的可见高度

 *  

 */

public class MainActivity extends Activity {

    private ScrollView mScrollView;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        init();

    }

    private void init(){

        mScrollView=(ScrollView) findViewById(R.id.scrollView);

        mScrollView.setOnTouchListener(new TouchListenerImpl());

    }

    private class TouchListenerImpl implements OnTouchListener{

        @Override

        public boolean onTouch(View view, MotionEvent motionEvent) {

            switch (motionEvent.getAction()) {

            case MotionEvent.ACTION_DOWN:

                break;

            case MotionEvent.ACTION_MOVE:

                 int scrollY=view.getScrollY();

                 int height=view.getHeight();

                 int scrollViewMeasuredHeight=mScrollView.getChildAt(0).getMeasuredHeight();

                 if(scrollY==0){

                        System.out.println("滑动到了顶端 view.getScrollY()="+scrollY);

                    }

                 if((scrollY+height)==scrollViewMeasuredHeight){

                        System.out.println("滑动到了底部 scrollY="+scrollY);

                        System.out.println("滑动到了底部 height="+height);

                        System.out.println("滑动到了底部 scrollViewMeasuredHeight="+scrollViewMeasuredHeight);

                    }

                break;

            default:

                break;

            }

            return false;

        }

         

    };

}