Android Studio如何将ScrollView设置为Scroll＆＃34; SLOWLY＆＃34;向下

Question

我已经有了滚动滚动视图的代码一直向下onCreate。但我的问题是我用来实现这一目的的代码使自动滚动变得更快。我需要慢慢滚动滚动视图。我需要这样做，因为我有一个正在阅读我工作内容的narator。因此我想在Narator阅读时自动向下滚动内容。为此，我使用以下代码：

final ScrollView sv = (ScrollView) findViewById(R.id.sv);
    sv.fullScroll(sv.FOCUS_DOWN);
    sv.postDelayed(new Runnable() {
        @Override
        public void run() {
            sv.fullScroll(sv.FOCUS_DOWN);
        }
    },100L);

这里也是我的所有代码

package org.intercode.lifeatceu;

import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.ScrollView;

public class pm extends AppCompatActivity {

LinearLayout ll;
MediaPlayer mpPM;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_pm);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    ll = (LinearLayout) findViewById(R.id.ll);

    mpPM = MediaPlayer.create(this,R.raw.pm);
    mpPM.start();

    final ScrollView sv = (ScrollView) findViewById(R.id.sv);
    sv.fullScroll(sv.FOCUS_DOWN);
    sv.postDelayed(new Runnable() {
        @Override
        public void run() {
            sv.fullScroll(sv.FOCUS_DOWN);
        }
    },100L);
}
@Override
public boolean onCreateOptionsMenu(Menu menu){
    getMenuInflater().inflate(R.menu.menu_mainmenu,menu);
    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item){
    int id = item.getItemId();
    switch(id){
        case R.id.menu_home:
            startActivity(new Intent(this, mainmenu.class));
            mpPM.stop();

            break;
        case R.id.menu_browse:
            startActivity(new Intent(this, browse.class));
            mpPM.stop();

            break;
        case R.id.menu_quiz:
            startActivity(new Intent(this, Chooselevel.class));
            mpPM.stop();

            break;
    }
    return super.onOptionsItemSelected(item);
}
@Override
public void onBackPressed()
{
    mpPM.stop();
    startActivity(new Intent(getApplicationContext(), browse.class));

}
@Override
protected void onStop()
{
    super.onStop();
    mpPM.stop();
}

}

我的问题是，如何更改滚动的速度？