Android仿QQ可拉伸头部控件

本文实例为大家分享了android仿qq可拉伸头部控件的具体实现代码，供大家参考，具体内容如下

该控件大致思路：

1.采用继承listview加入头部view。
2.监听listview滚动。
3.自定义动画回弹。

先看效果吧：

activity-main.xml布局如下：

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="horizontal"
 tools:context=".mainactivity" >

 <com.example.headerlistview.headerlistview
 android:id="@+id/header_lv"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:cachecolorhint="@android:color/transparent"
 android:divider="@android:color/darker_gray"
 android:dividerheight="1dip"
 android:duplicateparentstate="true"
 android:scrollbars="none" >
 </com.example.headerlistview.headerlistview>

</linearlayout>

headerview.xml布局：

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:orientation="vertical" >

 <imageview 
 android:id="@+id/header_image"
 android:layout_width="match_parent"
 android:layout_height="150dip"
 android:scaletype="centercrop"
 android:src="@drawable/lifei987"
 />

</linearlayout>

list_item布局：

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="80dip"
 android:gravity="center_vertical"
 android:orientation="horizontal" >
"

 <imageview
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:src="@drawable/ic_launcher" />

 <linearlayout
 android:layout_width="match_parent"
 android:layout_height="80dip"
 android:layout_marginleft="10dip"
 android:orientation="vertical" >

 <textview
 android:id="@+id/tv_name"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_margintop="10dip"
 android:text="lifei" />

 <textview
 android:id="@+id/tv_describe"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_margintop="10dip"
 android:text="lifeiasdfasdfasfsadfasf" />
 </linearlayout>

</linearlayout>

activity代码：

package com.example.headerlistview;

import java.util.arraylist;
import java.util.hashmap;
import java.util.list;
import java.util.map;

import android.os.bundle;
import android.app.activity;
import android.view.layoutinflater;
import android.view.menu;
import android.view.view;
import android.widget.baseadapter;
import android.widget.imageview;
import android.widget.listview;
import android.widget.simpleadapter;

public class mainactivity extends activity {

 private headerlistview header_lv;

 private imageview header_iv;

 @override
 protected void oncreate(bundle savedinstancestate) {
 super.oncreate(savedinstancestate);
 setcontentview(r.layout.activity_main);
 getheaderview();
 initview();
 }


 private void initview() {
 // todo auto-generated method stub
 header_lv=(headerlistview) findviewbyid(r.id.header_lv);
 header_lv.addheaderview(getheaderview());
 header_lv.setheaderview(header_iv);
 header_lv.setadapter(getsimpleadapter());
 }

 public baseadapter getsimpleadapter(){
 list<map<string, object>> data=new arraylist<map<string,object>>();
 for(int i=0;i<15;i++){
 map<string, object> map=new hashmap<string, object>();
 map.put("name", "郑州___"+i);
 map.put("describe", "asdfasdfasdfasdfasdfsadfsad");
 data.add(map);
 }

 simpleadapter simpleadapter=new simpleadapter(this, data, r.layout.list_item, new string[]{"name","describe"}, new int[]{r.id.tv_name,r.id.tv_describe});
 return simpleadapter;
 }

 public view getheaderview(){
 view view= getlayoutinflater().inflate(r.layout.headerview, null);
 header_iv =(imageview) view.findviewbyid(r.id.header_image);
 return view;
 }

}

自定义控件headerlistview:

package com.example.headerlistview;

import java.security.spec.ecfield;

import android.annotation.suppresslint;
import android.content.context;
import android.util.attributeset;
import android.view.motionevent;
import android.view.view;
import android.view.animation.animation;
import android.view.animation.transformation;
import android.widget.imageview;
import android.widget.listview;

public class headerlistview extends listview {

 private imageview headerview;

 private int headerview_initheight;//imageview初始高度

 public void setheaderview(imageview headerview) {
 this.headerview = headerview;
 }

 public headerlistview(context context) {
 super(context);
 // todo auto-generated constructor stub
 }

 public headerlistview(context context, attributeset attrs, int defstyle) {
 super(context, attrs, defstyle);
 // todo auto-generated constructor stub
 }

 public headerlistview(context context, attributeset attrs) {
 super(context, attrs);
 // todo auto-generated constructor stub
 }

 /**
 * listview焦点改变时--获取iamgeview高度的初始值，该值不能在构造方法中获取
 */
 @override
 public void onwindowfocuschanged(boolean haswindowfocus) {
 // todo auto-generated method stub
 super.onwindowfocuschanged(haswindowfocus);
 if(haswindowfocus){
 this.headerview_initheight=headerview.getheight();
 }
 }

 @suppresslint("newapi") @override
 protected boolean overscrollby(int deltax, int deltay, int scrollx,
 int scrolly, int scrollrangex, int scrollrangey,
 int maxoverscrollx, int maxoverscrolly, boolean istouchevent) {
 // 滑动过头的时候调用
 boolean bl=resizeheaderview(deltay);

 return bl?true:super.overscrollby(deltax, deltay, scrollx, scrolly, scrollrangex,
 scrollrangey, maxoverscrollx, maxoverscrolly, istouchevent);
 }

 /**
 * 控制imageview高度的增加
 * @param deltay 偏移量
 */
 private boolean resizeheaderview(int deltay) {
 if(math.abs((double)deltay)<200){
 if(deltay<0){
 headerview.getlayoutparams().height=headerview.getheight()-deltay;
 //重新绘制
 headerview.requestlayout();
 }else{
 headerview.getlayoutparams().height=headerview.getheight()-deltay;
 headerview.requestlayout();
 }
 }

 return false;
 }

 @override
 protected void onscrollchanged(int l, int t, int oldl, int oldt) {
 // todo auto-generated method stub
 super.onscrollchanged(l, t, oldl, oldt);
 //获取imageview父控件
 view parent=(view) headerview.getparent();
 //当父控件的top值小于零或者高度大于原始高度时触发
 if(parent.gettop()<0||headerview.getheight()>headerview_initheight){
 headerview.getlayoutparams().height=headerview.getheight()+parent.gettop();
 parent.layout(parent.getleft(),0, parent.getright(), parent.getheight());
 headerview.requestlayout();
 }
 }

 @override
 public boolean ontouchevent(motionevent ev) {
 // todo auto-generated method stub
 if(ev.getaction()==motionevent.action_up||ev.getaction()==motionevent.action_cancel){
 myanimation animation=new myanimation(headerview, headerview_initheight);
 animation.setduration(200);
 headerview.startanimation(animation);
 }
 return super.ontouchevent(ev);
 }

 public class myanimation extends animation{

 private imageview header_iv;
 private int currentheight;
 private int targetheight;
 private int poorheight;

 public myanimation(imageview iv,int targetheight){
 this.header_iv=iv;
 this.targetheight=targetheight;
 this.currentheight=iv.getheight();
 this.poorheight=this.currentheight-this.targetheight;
 }

 /**
 * 动画执行期间执行该方法，不断执行
 * interpolatedtime：当前时间与duration的时间比（时间执行百分比）
 */
 @override
 protected void applytransformation(float interpolatedtime,
 transformation t) {
 // todo auto-generated method stub
 super.applytransformation(interpolatedtime, t);
 this.header_iv.getlayoutparams().height=(int)(currentheight-poorheight*interpolatedtime);
 this.header_iv.requestlayout();
 }
 }

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。