Android实现字幕滚动的方法

本文实例介绍了安卓android实现字幕滚动效果的方法。主要是一个现成的java类文件实现的，该程序由android达人tony编写，本次是转发，还望原作者tony不要介意。这个android字幕滚动类的自定义功能比较多，可定义当前滚动到结尾时的停顿时间，单位：毫秒，还可设置当前的滚动速度，值越小，速度越快。

主要实现代码如下：

package com.tony.autoscroll;
import android.content.context;
import android.os.handler;
import android.util.attributeset;
import android.util.log;
import android.view.motionevent;
import android.widget.scrollview;
/**
 * @author tony
 */
public class autoscrollview extends scrollview {
 private final handler handler   = new handler();
 private long     duration   = 50;
 private boolean    isscrolled  = false;
 private int      currentindex = 0;
 private long     period    = 1000;
 private int      currenty   = -1;
 private double   x;
 private double   y;
 private int type = -1;
 /**
 * @param context
 */
 public autoscrollview(context context) {
 this(context, null);
 }
 /**
 * @param context
 * @param attrs
 */
 public autoscrollview(context context, attributeset attrs) {
 this(context, attrs, 0);
 }
 /**
 * @param context
 * @param attrs
 * @param defstyle
 */
 public autoscrollview(context context, attributeset attrs, int defstyle) {
 super(context, attrs, defstyle);
 }
 public boolean ontouchevent(motionevent event) {
 int action = event.getaction();
 switch (action) {
  case motionevent.action_down:
  x=event.getx();
  y=event.gety();
  if (type == 0) {
   setscrolled(false);
        }
  break;
  case motionevent.action_move:
  double movey = event.gety() - y;
  double movex = event.getx() - x;
  log.d("test", "movey = " + movey + " movex = " + movex );
  if ((movey>20||movey<-20) && (movex < 50 || movex > -50) && getparent() != null) {
   getparent().requestdisallowintercepttouchevent(true); 
        }
  break;
  case motionevent.action_up:
  if (type == 0) {
   currentindex = getscrolly();
   setscrolled(true);
        }
  break;
  default:
  break;
 }
    return super.ontouchevent(event); 
 }
  @override 
   public boolean onintercepttouchevent(motionevent p_event) 
   { 
  log.d("test", "onintercepttouchevent");
     return true; 
   } 
 /**
 * 判断当前是否为滚动状态
 * @return the isscrolled
 */
 public boolean isscrolled() {
 return isscrolled;
 }
 /**
 * 开启或者关闭自动滚动功能
 * @param isscrolled
 *      true为开启，false为关闭
 */
 public void setscrolled(boolean isscrolled) {
 this.isscrolled = isscrolled;
 autoscroll();
 }
 /**
 * 获取当前滚动到结尾时的停顿时间，单位：毫秒
 * @return the period
 */
 public long getperiod() {
 return period;
 }
 /**
 * 设置当前滚动到结尾时的停顿时间，单位：毫秒
 * @param period
 *the period to set
 */
 public void setperiod(long period) {
 this.period = period;
 }
 /**
 * 获取当前的滚动速度，单位：毫秒，值越小，速度越快。
 * @return the speed
 */
 public long getspeed() {
 return duration;
 }
 /**
 * 设置当前的滚动速度，单位：毫秒，值越小，速度越快。
 * @param speed
 *the duration to set
 */
 public void setspeed(long speed) {
 this.duration = speed;
 }
 public void settype(int type){
 this.type = type;
 }
 private void autoscroll() {
 handler.postdelayed(new runnable() {
  @override
  public void run() {
  boolean flag = isscrolled;
  if (flag) {
   //log.d("test", "currenty = " + currenty + " getscrolly() = "+ getscrolly() );
   if (currenty == getscrolly()) {
   try {
    thread.sleep(period);
   } catch (interruptedexception e) {
    e.printstacktrace();
   }
   currentindex = 0;
   scrollto(0, 0);
   handler.postdelayed(this, period);
   } else {
   currenty = getscrolly();
   handler.postdelayed(this, duration);
   currentindex++;
   scrollto(0, currentindex * 1);
   }
  } else {
  //currentindex = 0;
  //scrollto(0, 0);
  }
  }
 }, duration);
 }
}