android开发分享Android使用ScrollView实现滚动效果

  <?xml version="1.0" encoding="utf-8"?>  <android.support.constraint.constraintlayout xmlns:android="https://schemas.android.com/apk/res/android"    xmlns:app="https://schemas.android.com/apk/res-auto"    xmlns:tools="https://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.lenovo.scrollview.mainactivity">       <scrollview      android:id="@+id/scroll"      android:layout_width="match_parent"      android:layout_height="wrap_content"      android:scrollbars="none"><!--不显示右侧滚动条 -->         <textview        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:id="@+id/content"        />       </scrollview>     </android.support.constraint.constraintlayout>

  package com.example.lenovo.scrollview;     import android.annotation.suppresslint;  import android.app.activity;  import android.support.v7.app.appcompatactivity;  import android.os.bundle;  import android.util.log;  import android.view.motionevent;  import android.view.view;  import android.widget.button;  import android.widget.scrollview;  import android.widget.textview;     public class mainactivity extends activity {       private textview tv;    private scrollview scrollview;       @suppresslint("clickableviewaccessibility")    @override    protected void oncreate(bundle savedinstancestate) {      super.oncreate(savedinstancestate);      setcontentview(r.layout.activity_main);      tv=findviewbyid(r.id.content);      tv.settext(getresources().getstring(r.string.content));         scrollview=findviewbyid(r.id.scroll);      //设置监听器      scrollview.setontouchlistener(new view.ontouchlistener() {        public boolean ontouch(view view, motionevent motionevent) {          //对motionevent的参数作判断          switch (motionevent.getaction()){            case motionevent.action_up:            {              break;            }            case motionevent.action_down:            {              break;            }            case motionevent.action_move:{              /*              * (1)getscrolly()--滚动条滑动的距离,从0开始计算              * (2)getmeasuredheight()--全长              * (3)getheight()--一屏幕的高度              * */              //顶部状态              if(scrollview.getscrolly()<=0){                log.i("main","滑动到顶部");              }              //底部状态              if(scrollview.getchildat(0).getmeasuredheight()<=scrollview.getheight()+scrollview.getscrolly()){                log.i("main","滑动到底部");                tv.append(getresources().getstring(r.string.content));//滑动到底部时再次追加本篇文字              }                 break;            }             }          return false;        }      });    }     }