listview下拉刷新，上拉加载更多的实现方法

r囧r小猫 2022-08-04 16:47 217阅读 0赞

今天在某网站学习了listview的下拉刷新，上拉加载更多。记录一下防止忘记。

1.要实现listview的下拉刷新，上拉加载更多需要重写listview代码如下：

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.httprequest.R;  
  
  
public class ReflashLoadListView 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 iReflashListener;// 刷新数据的接口  
  
  
View footer;// 底部布局  
int totalItemCount;// 总数量  
int lastVisibleItem;// 最后一个可见的Item  
boolean isLoading;// 正在加载  
ILoadListener iLoadListener;  
  
  
public ReflashLoadListView(Context context) \{  
super(context);  
initView(context);  
\}  
  
  
public ReflashLoadListView(Context context, AttributeSet attrs) \{  
super(context, attrs);  
initView(context);  
\}  
  
  
public ReflashLoadListView(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,添加底部加载提示布局到listview  
\*   
\* @param context  
\*/  
private void initView(Context context) \{  
  
  
LayoutInflater inflater = LayoutInflater.from(context);  
  
  
header = inflater.inflate(R.layout.header\_layout, null);  
measureView(header);  
headerHeight = header.getMeasuredHeight();  
Log.i("tag", "headerHeight = " + headerHeight);  
topPadding(-headerHeight);  
this.addHeaderView(header);  
  
  
footer = inflater.inflate(R.layout.footer\_layout, null);  
footer.findViewById(R.id.load\_layout).setVisibility(View.GONE);  
this.addFooterView(footer);  
this.setOnScrollListener(this);  
\}  
  
  
@Override  
public void onScrollStateChanged(AbsListView view, int scrollState) \{  
this.scrollState = scrollState;  
if (totalItemCount == lastVisibleItem && scrollState == SCROLL\_STATE\_IDLE) \{  
if (!isLoading) \{  
isLoading = true;  
footer.findViewById(R.id.load\_layout).setVisibility(View.VISIBLE);  
// 加载更多  
iLoadListener.onLoad();  
\}  
  
  
\}  
\}  
  
  
@Override  
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) \{  
this.firstVisibleItem = firstVisibleItem;  
this.lastVisibleItem = firstVisibleItem + visibleItemCount;  
this.totalItemCount = totalItemCount;  
\}  
  
  
/\*\*  
\* 通知父布局，占用的宽，高；  
\*   
\* @param view  
\*/  
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);  
\}  
int width = ViewGroup.getChildMeasureSpec(0, 0, p.width);  
int height;  
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；  
\*   
\* @param topPadding  
\*/  
private void topPadding(int topPadding) \{  
header.setPadding(header.getPaddingLeft(), topPadding, header.getPaddingRight(), header.getPaddingBottom());  
header.invalidate();  
\}  
  
  
@Override  
public boolean onTouchEvent(MotionEvent ev) \{  
// TODO Auto-generated method stub  
switch (ev.getAction()) \{  
case MotionEvent.ACTION\_DOWN:  
if (firstVisibleItem == 0) \{  
isRemark = true;  
startY = (int) ev.getY();  
\}  
break;  
  
  
case MotionEvent.ACTION\_MOVE:  
onMove(ev);  
break;  
case MotionEvent.ACTION\_UP:  
if (state == RELESE) \{  
state = REFLASHING;  
// 加载最新数据；  
reflashViewByState();  
iReflashListener.onReflash();  
\} else if (state == PULL) \{  
state = NONE;  
isRemark = false;  
reflashViewByState();  
\}  
break;  
\}  
return super.onTouchEvent(ev);  
\}  
  
  
/\*\*  
\* 判断移动过程操作；  
\*   
\* @param ev  
\*/  
private void onMove(MotionEvent ev) \{  
if (!isRemark) \{  
return;  
\}  
int tempY = (int) ev.getY();  
int space = tempY - startY;  
int topPadding = space - headerHeight;  
switch (state) \{  
case NONE:  
if (space > 0) \{  
state = PULL;  
reflashViewByState();  
\}  
break;  
case PULL:  
topPadding(topPadding);  
if (space > headerHeight + 30 && scrollState == SCROLL\_STATE\_TOUCH\_SCROLL) \{  
state = RELESE;  
reflashViewByState();  
\}  
break;  
case RELESE:  
topPadding(topPadding);  
if (space < headerHeight + 30) \{  
state = PULL;  
reflashViewByState();  
\} else if (space <= 0) \{  
state = NONE;  
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() \{  
state = NONE;  
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);  
\}  
  
  
/\*\*  
\* 刷新数据的回调接口  
\*   
\* @author Administrator  
\*/  
public interface IReflashListener \{  
public void onReflash();  
\}  
  
  
/\*\*  
\* 加载完毕  
\*/  
public void LoadComplete() \{  
isLoading = false;  
footer.findViewById(R.id.load\_layout).setVisibility(View.GONE);  
\}  
  
  
/\*\*  
\* 加载更多数据的回调接口  
\*   
\* @author Administrator  
\*   
\*/  
public interface ILoadListener \{  
public void onLoad();  
\}  
  
  
/\*\*  
\* 设置回调接口  
\*   
\* @param iReflashListener  
\* @param iLoadListener  
\*/  
public void setInterface(IReflashListener iReflashListener, ILoadListener iLoadListener) \{  
this.iReflashListener = iReflashListener;  
this.iLoadListener = iLoadListener;  
\}  
\}

2.header\_layout布局文件如下：

<?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" >  
  
  
    <RelativeLayout  
        android:layout\_width="match\_parent"  
        android:layout\_height="wrap\_content"  
        android:paddingBottom="10dip"  
        android:paddingTop="10dip" >  
  
  
        <LinearLayout  
            android:id="@+id/layout"  
            android:layout\_width="wrap\_content"  
            android:layout\_height="wrap\_content"  
            android:layout\_centerInParent="true"  
            android:gravity="center"  
            android:orientation="vertical" >  
  
  
            <TextView  
                android:id="@+id/tip"  
                android:layout\_width="wrap\_content"  
                android:layout\_height="wrap\_content"  
                android:text="下拉可以刷新！" />  
  
  
            <TextView  
                android:id="@+id/lastupdate\_time"  
                android:layout\_width="wrap\_content"  
                android:layout\_height="wrap\_content" />  
        </LinearLayout>  
  
  
        <ImageView  
            android: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" />  
  
  
        <ProgressBar  
            android: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>

3.footer\_layout布局如下：

4.使用方法：

a.将布局中使用listview的地方换成 xxx.xxx.xxx.ReflashLoadListView

b.代码中listview换成ReflashLoadListView,并实现ILoadListener和IReflashListener两个接口，如在MainActivity中使用可以这样写public class MainActivity extends Activity           implements ILoadListener, IReflashListener

c.重写其中的两个方法onReflash()和onLoad()如：

public void onReflash() \{  
  
 //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();  
\}

public void onLoad() \{   
//获取更多数据  
getLoadData();  
//更新listview显示；  
showListView(apk\_list);  
//通知listview加载完毕  
listview.loadComplete();  
\}

d.并在初始化listview后为listview设置接口listView.setInterface(this, this);