下拉刷新(二)!

本文主要是介绍下拉刷新(二)!，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

先看主布局activity_main.xml

<RelativeLayout 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:background="@color/white"tools:context=".MainActivity" ><com.imooc.listviewfrashdemo1.ReFlashListViewandroid:id="@+id/listview"android:layout_width="fill_parent"android:layout_height="fill_parent"android:background="@color/white"android:cacheColorHint="#00000000"android:dividerHeight="5dip" />
</RelativeLayout>

再看头布局header_layout.xml

<?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" ><RelativeLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:paddingBottom="10dip"android:paddingTop="10dip" ><LinearLayoutandroid:id="@+id/layout"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_centerInParent="true"android:gravity="center"android:orientation="vertical" ><TextViewandroid:id="@+id/tip"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="下拉可以刷新！" /><TextViewandroid:id="@+id/lastupdate_time"android:layout_width="wrap_content"android:layout_height="wrap_content" /></LinearLayout><ImageViewandroid:id="@+id/arrow"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_toLeftOf="@id/layout"android:layout_marginRight="20dip"android:src="@drawable/pull_to_refresh_arrow" /><ProgressBarandroid:id="@+id/progress"style="?android:attr/progressBarStyleSmall"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_toLeftOf="@id/layout"android:layout_marginRight="20dip"android:visibility="gone" /></RelativeLayout></LinearLayout>

在看listview的每个item的布局

item_layout.xml

<?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="match_parent"android:orientation="vertical" ><LinearLayoutandroid:layout_width="fill_parent"android:layout_height="60dip"android:gravity="center_vertical"android:background="@drawable/app_item_bg"android:orientation="horizontal" ><ImageViewandroid:id="@+id/item3_apkiv"android:layout_width="50dip"android:layout_height="50dip"android:background="@drawable/test_icon"android:layout_marginLeft="10dip" /><LinearLayoutandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_weight="1"android:layout_marginLeft="10dip"android:orientation="vertical" ><TextViewandroid:id="@+id/item3_apkname"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="应用程序名字"android:textColor="@color/black"android:textSize="18dip" /><TextViewandroid:id="@+id/item3_apkinfo"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginTop="5dip"android:text="应用程序信息"android:textSize="14dip" /></LinearLayout><Buttonandroid:layout_width="60dip"android:layout_height="30dip"android:background="@drawable/ic_launcher"android:id="@+id/item3_dlbtn"android:layout_marginRight="10dip"android:text="安装"/></LinearLayout><TextViewandroid:id="@+id/item3_apkdes"android:layout_width="fill_parent"android:layout_height="30dip"android:layout_marginLeft="5dip"android:layout_marginRight="5dip"android:gravity="center_vertical"android:text="应用程序描述"android:textSize="14dip" /></LinearLayout>

以上的三个布局可以看截图，知道个大概，这个不是主要的

接下来看bean类

ApkEntity

package com.imooc.listviewfrashdemo1;public class ApkEntity {private String name;private String des;private String info;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDes() {return des;}public void setDes(String des) {this.des = des;}public String getInfo() {return info;}public void setInfo(String info) {this.info = info;}}

接下来看主程代码

MainActivity

package com.imooc.listviewfrashdemo1;import java.util.ArrayList;import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;import com.example.listviewfrashdemo1.R;
import com.imooc.listviewfrashdemo1.ReFlashListView.IReflashListener;public class MainActivity extends Activity implements IReflashListener {ArrayList<ApkEntity> apk_list;MyAdapter adapter;ReFlashListView listview;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);// 加载布局--只有一个listViewsetContentView(R.layout.activity_main);// 设置数据setData();//填充数据showList(apk_list);}/*** 设置数据源*/private void setData() {apk_list = new ArrayList<ApkEntity>();for (int i = 0; i < 10; i++) {ApkEntity entity = new ApkEntity();entity.setName("默认数据");entity.setInfo("50w用户");entity.setDes("这是一个神奇的应用");apk_list.add(entity);}}private void showList(ArrayList<ApkEntity> apk_list) {if (adapter == null) {listview = (ReFlashListView) findViewById(R.id.listview);//为本类设置监听，然后implements IReflashListenerlistview.setInterface(this);adapter = new MyAdapter(this, apk_list);//如果适配器为null,设置适配器即可listview.setAdapter(adapter);} else {//如果适配器不为null,就更新数据源，进行notifyDataSetChanged()adapter.onDateChange(apk_list);}}/*** 实现刷新操作的回调方法*/@Overridepublic void onReflush () {Handler handler = new Handler();handler.postDelayed(new Runnable() {@Overridepublic void run() {// 获取最新数据setReflashData();// 通知界面显示showList(apk_list);// 通知listview 刷新数据完毕！！！！！！！！！！！！！！listview.reflashComplete();}}, 2000);}private void setReflashData() {for (int i = 0; i < 2; i++) {ApkEntity entity = new ApkEntity();entity.setName("刷新数据");entity.setDes("这是一个神奇的应用");entity.setInfo("50w用户");apk_list.add(0, entity);}}}

接下来看适配器代码

MyAdapter

package com.imooc.listviewfrashdemo1;import java.util.ArrayList;import com.example.listviewfrashdemo1.R;import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;public class MyAdapter extends BaseAdapter {ArrayList<ApkEntity> apk_list;LayoutInflater inflater;public MyAdapter(Context context, ArrayList<ApkEntity> apk_list) {this.apk_list = apk_list;this.inflater = LayoutInflater.from(context);}public void onDateChange(ArrayList<ApkEntity> apk_list) {this.apk_list = apk_list;this.notifyDataSetChanged();}@Overridepublic int getCount() {return apk_list.size();}@Overridepublic Object getItem(int position) {return apk_list.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ApkEntity entity = apk_list.get(position);ViewHolder holder;if (convertView == null) {holder = new ViewHolder();convertView = inflater.inflate(R.layout.item_layout, null);holder.name_tv = (TextView) convertView.findViewById(R.id.item3_apkname);holder.des_tv = (TextView) convertView.findViewById(R.id.item3_apkdes);holder.info_tv = (TextView) convertView.findViewById(R.id.item3_apkinfo);convertView.setTag(holder);}else{holder = (ViewHolder) convertView.getTag();}holder.name_tv.setText(entity.getName());holder.des_tv.setText(entity.getDes());holder.info_tv.setText(entity.getInfo());return convertView;}class ViewHolder {TextView name_tv;TextView des_tv;TextView info_tv;}
}

接下来看自定义listview类了（里面代码详细）

ReFlashListView

package com.imooc.listviewfrashdemo1;import java.text.SimpleDateFormat;
import java.util.Date;import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;import com.example.listviewfrashdemo1.R;
/*** 隐藏头布局--先测量父布局，获取头布局高度，设置padding,然后隐藏头布局，listview在添加头布局* 设置监听事件* 判断ontouch时间* 设置监听加载刷新的数据*/
public class ReFlashListView extends ListView implements OnScrollListener {View header;// 顶部布局文件；int headerHeight;// 顶部布局文件的高度；int firstVisibleItem;// 当前第一个可见的item的位置；int scrollState;// listview 当前滚动状态；boolean isRemark;// 标记，当前是在listview最顶端摁下的；int startY;// 摁下时的Y值；int state;// 当前的状态；final int NONE = 0;// 正常状态；final int PULL = 1;// 提示下拉状态；final int RELESE = 2;// 提示释放状态；final int REFLASHING = 3;// 刷新状态；IReflashListener iReflushListener;//刷新数据的接口/*** 三个构造方法，并且初始化视图*/public ReFlashListView(Context context) {super(context);initView(context);}public ReFlashListView(Context context, AttributeSet attrs) {super(context, attrs);initView(context);}public ReFlashListView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);initView(context);}/*** 初始化界面，添加顶部布局文件到 listview*/private void initView(Context context) {LayoutInflater inflater = LayoutInflater.from(context);header = inflater.inflate(R.layout.header_layout, null);//先测量父布局，不然headerHeight为0measureView(header);//获取头布局文件的高度headerHeight = header.getMeasuredHeight();Log.i("tag", "headerHeight = " + headerHeight);//隐藏头布局文件topPadding(-headerHeight);//listview添加头布局this.addHeaderView(header);//设置滑动监听this.setOnScrollListener(this);}/*** 通知父布局，占用的宽，高；*/private void measureView(View view) {ViewGroup.LayoutParams p = view.getLayoutParams();if (p == null) {p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT);}/*** 因为listView不限制高度。child有多高，listView就给它多高的空间* 但是listView是限制宽度的，所以需要getChildMeasureSpec*/int width = ViewGroup.getChildMeasureSpec(0, 0, p.width);int height;//获取itme的高度值int tempHeight = p.height;if (tempHeight > 0) {height = MeasureSpec.makeMeasureSpec(tempHeight,MeasureSpec.EXACTLY);} else {height = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);}view.measure(width, height);}/*** 设置header 布局 上边距；--站在父布局的角度看待问题*/private void topPadding(int topPadding) {header.setPadding(header.getPaddingLeft(), topPadding,header.getPaddingRight(), header.getPaddingBottom());header.invalidate();}/*** 实现接口方法*/@Overridepublic void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) {this.firstVisibleItem = firstVisibleItem;}@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) {this.scrollState = scrollState;}/*** 实现touch方法*/@Overridepublic boolean onTouchEvent(MotionEvent ev) {switch (ev.getAction()) {/*** 如果手指按下，如果firstVisibleItem == 0就设置标记为true,代表是在最顶端按下的* 并且获取按下的坐标Y轴距离*/case MotionEvent.ACTION_DOWN:if (firstVisibleItem == 0) {isRemark = true;startY = (int) ev.getY();}break;case MotionEvent.ACTION_MOVE:/*** 判断移动过程操作；*/onMove(ev);break;case MotionEvent.ACTION_UP:if (state == RELESE) {state = REFLASHING;// 加载最新数据；reflashViewByState();iReflushListener.onReflush();} else if (state == PULL) {state = NONE;isRemark = false;reflashViewByState();}break;}return super.onTouchEvent(ev);}/*** 当手指按下*/private void onMove(MotionEvent ev) {//如果不是在listview在最顶端时候按下的，直接返回，不做处理if (!isRemark) {return;}int tempY = (int) ev.getY();//获取移动的距离int space = tempY - startY;//获取最新的头布局的padding值int topPadding = space - headerHeight;switch (state) {/*** 判断刷新箭头的状态值*/case NONE://如果稍微移动就改成状态是--下拉可以刷新if (space > 0) {//如果是正常状态，就修改状态为下拉可以刷新state = PULL;//根据当前状态，改变界面显示；reflashViewByState();}break;case PULL://重绘最新的头布局隐藏程度topPadding(topPadding);//如果比头布局高度还大于30就直接改变状态值if (space-headerHeight>  30&& scrollState == SCROLL_STATE_TOUCH_SCROLL) {//修改状态为--松开可以刷新state = RELESE;reflashViewByState();}break;case RELESE://重绘最新的头布局隐藏程度topPadding(topPadding);if (space-headerHeight < 30) {//改变状态--下拉可以刷新state = PULL;reflashViewByState();} else if (space <= 0) {//当space<=0,即可见的item索引不是0state = NONE;//还原isRemark = false;reflashViewByState();}break;}}/*** 根据当前状态，改变界面显示；*/private void reflashViewByState() {TextView tip = (TextView) header.findViewById(R.id.tip);ImageView arrow = (ImageView) header.findViewById(R.id.arrow);ProgressBar progress = (ProgressBar) header.findViewById(R.id.progress);RotateAnimation anim = new RotateAnimation(0, 180,RotateAnimation.RELATIVE_TO_SELF, 0.5f,RotateAnimation.RELATIVE_TO_SELF, 0.5f);anim.setDuration(500);anim.setFillAfter(true);RotateAnimation anim1 = new RotateAnimation(180, 0,RotateAnimation.RELATIVE_TO_SELF, 0.5f,RotateAnimation.RELATIVE_TO_SELF, 0.5f);anim1.setDuration(500);anim1.setFillAfter(true);switch (state) {case NONE:arrow.clearAnimation();topPadding(-headerHeight);break;case PULL:arrow.setVisibility(View.VISIBLE);progress.setVisibility(View.GONE);tip.setText("下拉可以刷新！");arrow.clearAnimation();arrow.setAnimation(anim1);break;case RELESE:arrow.setVisibility(View.VISIBLE);progress.setVisibility(View.GONE);tip.setText("松开可以刷新！");arrow.clearAnimation();arrow.setAnimation(anim);break;case REFLASHING:topPadding(50);arrow.setVisibility(View.GONE);progress.setVisibility(View.VISIBLE);tip.setText("正在刷新...");arrow.clearAnimation();break;}}/*** 获取完数据；*/public void reflashComplete() {//将刷新状态还原成正常状态state = NONE;//还原状态isRemark = false;reflashViewByState();TextView lastupdatetime = (TextView) header.findViewById(R.id.lastupdate_time);SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日 hh:mm:ss");Date date = new Date(System.currentTimeMillis());String time = format.format(date);lastupdatetime.setText(time);}public void setInterface(IReflashListener iReflushListener){this.iReflushListener = iReflushListener;}/*** 刷新数据接口* @author Administrator*/public interface IReflashListener{public void onReflush();}
}

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