ListView中条目指定位置停留和动画效果

最近查看主流app练习时遇到了个挺蛋疼的布局实现,一个可以上下滑动布局滑动到指定条目时,这个条目在顶部停下来下面的条目还可以继续滑动,
于是照猫画虎的自己写了个实现,当指定一个位置停留时想清除了需求其实很简单,当条目位置确定是置顶后用另一个长相相同和这个条目相同的View覆盖就可以了.毕竟小弟刚学,对自定义控件不是特别熟练,就用了个特简单的方法实现.
//布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
   
    <ListView 
        android:id="@+id/lv_demo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        
        />
 <TextView 
     android:background="#fff"
        android:id="@+id/tv_listdemo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="条目1"
        android:visibility="invisible"
        />
</RelativeLayout>
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.TranslateAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class ListViewDemo extends Activity {
private ListView lv;
private List<String> list;
private TextView tv_demo;
private MyBaseAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.listdemo);
initView();
initData();
initLinter();
}
/**
 * 监听
 * */
private void initLinter() {
//滑动监听
lv.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
//当出现在指定位置为1时显示出来
if(firstVisibleItem==1){
tv_demo.setVisibility(View.VISIBLE);
}else if(firstVisibleItem<1){
tv_demo.setVisibility(View.GONE);
}
}
});
//条目监听
lv.setOnItemClickListener(new OnItemClickListener() {

@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
int id2 = lv.getSelectedItemPosition();
System.out.println(id2);
if(position>1){
//过时的方法
//int i = getWindowManager().getDefaultDisplay().getWidth();
//替代方法:通过获取分辨率信息来过去宽度
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int i = metrics.widthPixels;
//从左侧移动到最右侧
TranslateAnimation animation = new TranslateAnimation(0, i, 0, 0);
animation.setDuration(500);
view.startAnimation(animation);
final int state = position;
//动画监听
animation.setAnimationListener(new AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {
// TODO Auto-generated method stub
}
@Override
public void onAnimationRepeat(Animation animation) {
// TODO Auto-generated method stub
}
//动画结束
@Override
public void onAnimationEnd(Animation animation) {
//删除选定条目
list.remove(list.get(state));
//更新填充
adapter.notifyDataSetChanged();
}
});
}
}
});
}
/**
 * 数据填充
 * */
private void initData() {
list = new ArrayList<String>();
for (int i = 0; i < 50; i++) {
list.add("条目"+i);
}
adapter = new MyBaseAdapter(list);
lv.setAdapter(adapter);
}
/**
 * 数据初始化
 * */
private void initView() {
lv = (ListView) findViewById(R.id.lv_demo);
tv_demo = (TextView) findViewById(R.id.tv_listdemo);
}
class MyBaseAdapter extends BaseAdapter{

private List<String> list;

public MyBaseAdapter(List<String> list) {
this.list = list;
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}

@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView==null){
convertView = View.inflate(ListViewDemo.this, R.layout.item_lv_main, null);
}
TextView view = (TextView) convertView.findViewById(R.id.tv_item);
view.setText(list.get(position));
return convertView;
}
}
}