scrollview监听滑动位置

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 ;
        }

    };
}