仿照知乎Android APP五——为ListView中同时实现上拉加载和下拉刷新，点击
模仿知乎Android APP五——为ListView中同时实现上拉加载和下拉刷新，点击
结果图：
上拉加载之前跟大家分享过，就是通过监听listview的滚动事件，确定最后一个可视条目为listview的最后一个条目，这时候用户继续下拉，就去加载更多，然后需要注意的是需要本次加载完成之后才能去加载更多，所以需要有一个flag去标志是否完成加载。用户执行下拉刷新或者是上拉加载的操作是不同时的，就是下拉刷新的时候不能上拉加载，反之亦然。这样下拉就可以完成这个功能。
下拉刷新，首先，我们下拉得到的数据需要添加在原有数据的前面。然后下拉刷新的时候我们需要注意的地方一个是header的显示，他的提示文字随着用户的滑动不停的改变。然后当用户滑动到一定程度的时候，释放可以刷新数据。
所以，我们首先需要定义上拉刷新的四种状态，没有动作，开始下拉，释放可以刷新，正在刷新。然后，我们首次需要隐藏掉header，就利用到header的padding Top，不断改变该属性可以实现header随用户手滑动而改变。大概的效果如下图
下面是详细的代码实现：自定义ListView，继承ListView，然后实现OnScrollListener，主要的功能：下拉刷新header的显示处理，下拉加载footer的显示处理，定义两个接口对应下拉刷新和上拉加载，用于接口回调，与Activity通行。没有什么，需要注意一点的就是下拉刷新过程中的header可以转变的，可以有NONE 到RELEASE 反之也可以，需要作出处理，每一次处理之后都要及时调用refreshHeaderViewByState这个方法去重新显示header。当用户拖动的距离大于headerHeigh+30之后就可以松开刷新了，这个是可以自定义的。
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
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.guanggong.operatestdemo01.R;
/**
* @author Administrator liweijie
* @since 5.19
* @version 2.0
* 是一个自定义的listview，可作用于上拉刷新下拉加载
*
*/
@SuppressLint("ClickableViewAccessibility")
public class OperaSumListView extends ListView implements OnScrollListener
{
// 区分是下拉刷新还是上拉加载
public static final int LOAD = 0;
public static final int REFRESH = 1;
// 这是上拉加载的一些view+需要的变量
private View footer;
private TextView loadFull;
private TextView noData;
private TextView loading;
private ProgressBar loadProgressbar;
private int lastVisiableitem;
private int totleItem;
private boolean isLoading = false; // 每一次都需要先把上次加载的完成之后才可以去加载下一次
//用于保证下拉刷新的时候不可以上拉加载，反之一样
private boolean isRefresh = false;
private boolean isLoad = false;
private View header;
private int heighHeader;
private int SPACE = 30; // 控制下拉到什么程度的时候开始改变state的值为RELEASE,松开可以刷新
private int scrollState; // 滚动状态，只有是手指摁在屏幕导致的下拉刷新事件有效，假如是由于惯性的则无销，个人设定
private int firstVisiableItem; // 第一个可见的item，用于判断当前情况是否可以下拉刷新
private boolean isRemark = false;// 标记是否正在下拉刷新状态
private int startY;// 手指摁下的时候后的y值
private ImageView arrow;
private TextView tip;
private TextView lastUpdate;
private ProgressBar refreshBar;
// 下拉刷新的四种状态，一开始没有显示出来为NONE
// 下拉显示出header的时候提示信息有所改变，下拉可刷新
// 下拉一定程度的时候文字变为松开可刷新
// 最后为正在刷新
private static final int NONE = 0;
private static final int PULL = 1;
private static final int RELEASE = 2;
private static final int REFRESHING = 3;
private int state;
// 箭头动画
private RotateAnimation anim;
private RotateAnimation anim1;
public OperaSumListView(Context context)
{
super(context);
initView(context);
}
public OperaSumListView(Context context, AttributeSet attrs)
{
super(context, attrs);
initView(context);
}
public OperaSumListView(Context context, AttributeSet attrs, int defStyleAttr)
{
super(context, attrs, defStyleAttr);
initView(context);
}
/**
* 每一次header的状态改变的时候都需要对他的布局进行相关的处理
*/
@SuppressLint("InflateParams")
private void initView(Context context)
{
anim = new RotateAnimation(0, -180, RotateAnimation.RELATIVE_TO_SELF, (float) 0.5,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
anim.setDuration(400);
anim.setFillAfter(true);
anim1 = new RotateAnimation(180, 0, RotateAnimation.RELATIVE_TO_SELF, (float) 0.5,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
anim1.setDuration(400);
anim1.setFillAfter(true);
LayoutInflater inflater = LayoutInflater.from(context);
footer = inflater.inflate(R.layout.opera_sumfragment_listview_footer, null);
loadFull = (TextView) footer.findViewById(R.id.id_sum_listview_footer_lv_textview01);
noData = (TextView) footer.findViewById(R.id.id_sum_listview_footer_lv_textview02);
loading = (TextView) footer.findViewById(R.id.id_sum_listview_footer_lv_textview03);
loadProgressbar = (ProgressBar) footer.findViewById(R.id.id_sum_listview_footer_lv_progress);
this.addFooterView(footer);
footer.setVisibility(View.GONE);
header = inflater.inflate(R.layout.opera_sumfragment_listview_header, null);
arrow = (ImageView) header.findViewById(R.id.id_sum_listview_header_lv_rv_imageview);
tip = (TextView) header.findViewById(R.id.id_sum_listview_header_lv_rv_lv_textview);
lastUpdate = (TextView) header.findViewById(R.id.id_sum_listview_header_lv_rv_lv_textview02);
lastUpdate.setText(new SimpleDateFormat("yyyy年MM月dd日 hh时mm分ss秒", Locale.getDefault())
.format(new Date()));
refreshBar = (ProgressBar) header.findViewById(R.id.id_sum_listview_header_lv_rv_progress);
measureHeader(header);
heighHeader = header.getMeasuredHeight();
toPadding(-heighHeader);
this.addHeaderView(header);
this.setOnScrollListener(this);
}
private void measureHeader(View child)
{
ViewGroup.LayoutParams lp = child.getLayoutParams();
if (lp == null)
{
lp = new android.view.ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
}
int widthSpec = ViewGroup.getChildMeasureSpec(0, 0, lp.width);
int temp = lp.height;
int heighSpec;
if (temp > 0)
{
heighSpec = MeasureSpec.makeMeasureSpec(temp, MeasureSpec.EXACTLY);
} else
{
heighSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
}
child.measure(widthSpec, heighSpec);
}
/**
* 设置header的padding top的值
*
* @param i
*/
private void toPadding(int i)
{
header.setPadding(header.getPaddingLeft(), i, header.getPaddingRight(),
header.getPaddingBottom());
header.invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent ev)
{
switch (ev.getAction())
{
case MotionEvent.ACTION_DOWN: // 首次手指摁下
if (firstVisiableItem == 0)
{
isRemark = true;
startY = (int) ev.getY();
}
break;
case MotionEvent.ACTION_MOVE:// 手指移动
whenMove(ev);
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:// 手指抬起
System.out.println("state=" + state);
if (state == PULL || state == NONE)
{
state = NONE;
refreshHeaderViewByState();
} else if (state == RELEASE)
{
System.out.println("有执行到");
state = REFRESHING;
refreshHeaderViewByState();
if (onRefreshListener != null && !isLoad)
{
isRefresh = true;
onRefreshListener.onRefresh();
}
}
isRemark = false;
break;
}
return super.onTouchEvent(ev);
}
/**
* 用于控制移动时候的状态改变和切换 计算padding top的值
*
* @param ev
*/
private void whenMove(MotionEvent ev)
{
if (!isRemark)
{
return;
}
int tmpY = (int) ev.getY();
int space = tmpY - startY;
int topPadding = space - heighHeader;
switch (state)
{
case NONE:
if (space > 0)
{
state = PULL;
refreshHeaderViewByState();
}
break;
case PULL:
toPadding(topPadding);
if (space > heighHeader + SPACE && scrollState == OnScrollListener.SCROLL_STATE_TOUCH_SCROLL)
{
state = RELEASE;
refreshHeaderViewByState();
} else if (space < 0)
{
state = NONE;
refreshHeaderViewByState();
}
break;
case RELEASE:
toPadding(topPadding);
if (space < heighHeader + SPACE && space > 0)
{
state = PULL;
refreshHeaderViewByState();
} else if (space <= 0)
{
state = NONE;
refreshHeaderViewByState();
}
break;
}
}
/**
* 每一次header的状态改变的时候都需要对他的布局进行相关的处理
*/
private void refreshHeaderViewByState()
{
switch (state)
{
case NONE:
toPadding(-heighHeader);
break;
case PULL:
tip.setText("下拉可以刷新");
arrow.clearAnimation();
arrow.setAnimation(anim1);
arrow.startAnimation(anim1);
refreshBar.setVisibility(View.GONE);
arrow.setVisibility(View.VISIBLE);
break;
case RELEASE:
tip.setText("松开可以刷新");
arrow.clearAnimation();
arrow.setAnimation(anim);
arrow.startAnimation(anim);
arrow.setVisibility(View.VISIBLE);
refreshBar.setVisibility(View.GONE);
break;
case REFRESHING:
System.out.println("123有执行力过");
toPadding(30);
arrow.clearAnimation();
arrow.setVisibility(View.GONE);
refreshBar.setVisibility(View.VISIBLE);
tip.setText("正在刷新");
}
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState)
{
this.scrollState = scrollState;
if (lastVisiableitem == totleItem && scrollState == OnScrollListener.SCROLL_STATE_IDLE &&!isRefresh)
{
if (!isLoading)
{
isLoading = true;
isLoad = true;
footer.setVisibility(View.VISIBLE);
if (onLoadListener != null)
{
onLoadListener.onLoad();
}
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
int totalItemCount)
{
this.firstVisiableItem = firstVisibleItem;
this.lastVisiableitem = firstVisibleItem + visibleItemCount;
this.totleItem = totalItemCount;
}
/**
* 上拉加载监听
*
* @author Administrator
*
*/
public interface OnLoadListener
{
void onLoad();
}
private OnLoadListener onLoadListener;
public void setOnLoadListener(OnLoadListener onLoadListener)
{
this.onLoadListener = onLoadListener;
}
/**
* 下拉刷新监听
*
* @author Administrator
*
*/
public interface OnRefreshListener
{
void onRefresh();
}
private OnRefreshListener onRefreshListener;
public void setOnRefreshListener(OnRefreshListener onRefreshListener)
{
this.onRefreshListener = onRefreshListener;
}
/**
* 对于下拉加载的各种情况进行处理 1，数据还有很多，没有加载完成，下拉可以继续加载 2，数据本次加载完成，下次下拉不会再加载
* 3，数据已经之前巧合加载完成，不会再去加载
*
* @param result
*/
public void setFooterResult(int result)
{
isLoad = false;
System.out.println(result + "result");
if (result == 10)// 还有剩余数据
{
isLoading = false;
loading.setVisibility(View.VISIBLE);
loadProgressbar.setVisibility(View.VISIBLE);
noData.setVisibility(View.GONE);
loadFull.setVisibility(View.GONE);
footer.setVisibility(View.GONE);
} else if (result < 10 && result > 0)// 已经完全没有数据可以加载，这是最后一次加载数据
{
isLoading = true;
loading.setVisibility(View.GONE);
loadProgressbar.setVisibility(View.GONE);
noData.setVisibility(View.GONE);
loadFull.setVisibility(View.VISIBLE);
footer.setVisibility(View.VISIBLE);
} else
{
isLoading = true;// 已经完全没有数据可以加载
loading.setVisibility(View.GONE);
loadProgressbar.setVisibility(View.GONE);
noData.setVisibility(View.VISIBLE);
loadFull.setVisibility(View.GONE);
footer.setVisibility(View.VISIBLE);
}
}
/**
* 刷新完成之后需要做一些后续工作
*/
public void refreshCompleted(boolean flag)
{
isRefresh = false;
state = NONE;
isRemark = false;
if(flag)
{
lastUpdate.setText(new SimpleDateFormat("yyyy年MM月dd日 hh时mm分ss秒", Locale.getDefault())
.format(new Date()));
}
refreshHeaderViewByState();
}
}
由于这一篇blog是接着之前的，需要在OperaSumFragment之中去实现MyListView的接口，包括之前的一些处理，如下，代码
import java.util.List;
import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import com.guanggong.operatestdemo01.R;
import com.guanggong.operatestdemo01.Constant.Constant;
import com.guanggong.operatestdemo01.Tools.MyToast;
import com.guanggong.operatestdemo01.activity.OperaDetailNewsActivity;
import com.guanggong.operatestdemo01.adapter.OperaSumAdapter;
import com.guanggong.operatestdemo01.domain.NewsInfo;
import com.guanggong.operatestdemo01.thread.ThreadOfLoadXMLInfo;
import com.guanggong.operatestdemo01.view.OperaSumListView;
import com.guanggong.operatestdemo01.view.OperaSumListView.OnLoadListener;
import com.guanggong.operatestdemo01.view.OperaSumListView.OnRefreshListener;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer;
/**
* @author Administrator liweijie
* @since 5.12
* @version 1.0 设置OperaMultiFragment的第一个tab的内容Fragment 粤剧近况，他会显示最近的粤剧新闻
*
*/
public class OperaSumFragment extends Fragment implements OnItemClickListener,OnRefreshListener,OnLoadListener
{
private View mOperaSumFragmentLayoutView;
private OperaSumListView mListView;
private OperaSumAdapter mAdapter;
private DisplayImageOptions options;
private String path = "http://10.21.64.112:8080/web/News.xml";
@SuppressLint("HandlerLeak")
private Handler mHandler = new Handler()
{
@SuppressWarnings("unchecked")
public void handleMessage(android.os.Message msg)
{
if (msg.what == Constant.OK)//首次进入的时候自动去加载，成功之后就绑定适配器
{
mAdapter = new OperaSumAdapter(getActivity(), (List<NewsInfo>) msg.obj, options);
mListView.setAdapter(mAdapter);
}
if(msg.what == Constant.REFRESH_OK)//下拉刷新获取数据成功之后
{
mAdapter.addDatasToFirst((List<NewsInfo>) msg.obj);
mListView.refreshCompleted(true);
}
if(msg.what == Constant.LOAD_OK)<span style="font-family: Arial, Helvetica, sans-serif;">//上拉加载更多获取数据成功的时候</span>
{
mAdapter.addDatasToLadst((List<NewsInfo>) msg.obj);
mListView.setFooterResult(((List<NewsInfo>) msg.obj).size());
}
if (msg.what == Constant.ERROR)
{
MyToast.showToast(getActivity(), "获取失败，请检查网络");
mListView.refreshCompleted(false);
}
};
};
@SuppressLint("InflateParams")
@SuppressWarnings("deprecation")
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
mOperaSumFragmentLayoutView = inflater.inflate(R.layout.layout_of_operasum_fragment, null);
mListView = (OperaSumListView) mOperaSumFragmentLayoutView.findViewById(R.id.id_sum_lv_listview);
options = new DisplayImageOptions.Builder().showStubImage(R.drawable.ic_launcher)
.showImageForEmptyUri(R.drawable.ic_empty).showImageOnFail(R.drawable.ic_error)
.displayer(new RoundedBitmapDisplayer(20)).build();
new ThreadOfLoadXMLInfo(mHandler, path, Constant.OPERASUM_FRAGMENT).start();
mListView.setOnItemClickListener(this);
mListView.setOnRefreshListener(this);
mListView.setOnLoadListener(this);
return mOperaSumFragmentLayoutView;
}
/*
* (non-Javadoc)
*
* @see
* android.widget.AdapterView.OnItemClickListener#onItemClick(android.widget
* .AdapterView, android.view.View, int, long) 参数说明，第一个adapter
* 第二个，显示一个item的view，这里是包括三个textview+一个imageview 第三个在适配器额位置 第四个，他在listview的第几行
*/
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
String pathOfDetailed = ((NewsInfo) parent.getAdapter().getItem(position)).getPathOfDetailed();
if(!pathOfDetailed.equals(null) && pathOfDetailed.trim().length()>0)
{
Intent intent = new Intent(getActivity(), OperaDetailNewsActivity.class);
intent.putExtra(Constant.NewsDetailPath, pathOfDetailed);
System.out.println(pathOfDetailed+"详细新闻的路径");
startActivity(intent);
}
}
@Override
public void onLoad()
{
System.out.println("有执行加载");
path = "http://10.21.64.112:8080/web/load.xml";
new ThreadOfLoadXMLInfo(mHandler, path, Constant.OPERASUM_FRAGEMTN_LOAD).start();
}
@Override
public void onRefresh()
{
System.out.println("有执行刷新");
path = "http://10.21.64.112:8080/web/fresh.xml";
new ThreadOfLoadXMLInfo(mHandler, path, Constant.OPERASUM_FRAGEMTN_FRFRESH).start();
}
}
在ThreadOfLoadXMLInfo类中，多了如下的代码，由于下拉刷新或者是上拉加载，数据都是和之前的一开始进入OperaSumFragment去加载的一样，就可以使用同样的API去实现，不用写过多的方法。
//在sum，头条界面下拉刷新时候
case Constant.OPERASUM_FRAGEMTN_FRFRESH:
try
{
if (mNewsDatas.addAll(LoadInfoControl.getOperaSumData(loadPath)))
{
sendMessage(mNewsDatas,Constant.REFRESH_OK);
} else
{
uIHandler.sendEmptyMessage(Constant.ERROR);
}
} catch (Exception e)
{
e.printStackTrace();
}
break;
//上拉加载
case Constant.OPERASUM_FRAGEMTN_LOAD:
try
{
if (mNewsDatas.addAll(LoadInfoControl.getOperaSumData(loadPath)))
{
sendMessage(mNewsDatas,Constant.LOAD_OK);
} else
{
uIHandler.sendEmptyMessage(Constant.ERROR);
}
} catch (Exception e)
{
e.printStackTrace();
}
break;
结果图：