问安卓中特定字段后的ScrollView自动滚动

EN

package com.example.scrollview;

import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.EditText;
import android.widget.ScrollView;


public class MainActivity extends Activity{
EditText edtText4,edtText8;
ScrollView scrollView;
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

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

    edtText4 = (EditText)findViewById(R.id.editText4);
    edtText8 = (EditText)findViewById(R.id.editText8);  

    edtText4.setOnTouchListener(selectedFieldTouchListener);
    edtText8.setOnTouchListener(selectedFieldTouchListener);

}
private OnTouchListener selectedFieldTouchListener = new OnTouchListener() {

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        int top1 = 0;
        switch (v.getId()) {
        case R.id.editText4:
            top1 = edtText4.getTop();  
            break;
        case R.id.editText8:
            top1 = edtText8.getTop();
            break;
        }
        final int top = top1;
        scrollView.postDelayed(new Runnable() {//must be in postDelayed otherwise wont work

            @Override
            public void run() {
                scrollView.scrollTo(0, edtText4.getTop());
            }
        }, 100);

        return false;
    }
};