Android UI之下拉刷新上拉刷新实现

在实际开发中我们经常要用到上拉刷新和下拉刷新，因此今天我写了一个上拉和下拉刷新的demo，有一个自定义的下拉刷新控件

只需要在布局文件中直接引用就可以使用，非常方便，非常使用，以下是源代码；

自定义的ListView RTPullListView

 package com.ryantang.pulllistview;

 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.LinearInterpolator;
 import android.view.animation.RotateAnimation;
 import android.widget.AbsListView;
 import android.widget.AbsListView.OnScrollListener;
 import android.widget.BaseAdapter;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.ListView;
 import android.widget.ProgressBar;
 import android.widget.TextView;

 public class RTPullListView extends ListView implements OnScrollListener {
     private static final String TAG = "RTPullListView";

     private final static int RELEASE_To_REFRESH = 0;
     private final static int PULL_To_REFRESH = 1;
     private final static int REFRESHING = 2;
     private final static int DONE = 3;
     private final static int LOADING = 4;

     // 实际的padding的距离与界面上偏移距离的比例
     private final static int RATIO = 3;
     private LayoutInflater inflater;
     private LinearLayout headView;
     private TextView tipsTextview;
     private TextView lastUpdatedTextView;
     private ImageView arrowImageView;
     private ProgressBar progressBar;

     private RotateAnimation animation;
     private RotateAnimation reverseAnimation;

     // 用于保证startY的值在一个完整的touch事件中只被记录一次
     private boolean isRecored;

 //    private int headContentWidth;
     private int headContentHeight;

     private int startY;
     private int firstItemIndex;
     private int state;
     private boolean isBack;
     private OnRefreshListener refreshListener;

     private boolean isRefreshable;
     private boolean isPush;

     private int visibleLastIndex;
     private int visibleItemCount;

     public RTPullListView(Context context) {
         super(context);
         init(context);
     }

     public RTPullListView(Context context, AttributeSet attrs) {
         super(context, attrs);
         init(context);
     }

     private void init(Context context) {
         inflater = LayoutInflater.from(context);
         headView = (LinearLayout) inflater.inflate(R.layout.pulllist_head, null);
         arrowImageView = (ImageView) headView.findViewById(R.id.head_arrowImageView);
 //        arrowImageView.setMinimumWidth(70);
 //        arrowImageView.setMinimumHeight(50);
         progressBar = (ProgressBar) headView.findViewById(R.id.head_progressBar);
         tipsTextview = (TextView) headView.findViewById(R.id.head_tipsTextView);
         lastUpdatedTextView = (TextView) headView.findViewById(R.id.head_lastUpdatedTextView);

         measureView(headView);
         headContentHeight = headView.getMeasuredHeight();
 //        headContentWidth = headView.getMeasuredWidth();

         headView.setPadding(0, -1 * headContentHeight, 0, 0);
         headView.invalidate();

         addHeaderView(headView, null, false);
         setOnScrollListener(this);

         animation = new RotateAnimation(0, -180,
                 RotateAnimation.RELATIVE_TO_SELF, 0.5f,
                 RotateAnimation.RELATIVE_TO_SELF, 0.5f);
         animation.setInterpolator(new LinearInterpolator());
         animation.setDuration(250);
         animation.setFillAfter(true);

         reverseAnimation = new RotateAnimation(-180, 0,
                 RotateAnimation.RELATIVE_TO_SELF, 0.5f,
                 RotateAnimation.RELATIVE_TO_SELF, 0.5f);
         reverseAnimation.setInterpolator(new LinearInterpolator());
         reverseAnimation.setDuration(200);
         reverseAnimation.setFillAfter(true);

         state = DONE;
         isRefreshable = false;
         isPush = true;
     }

     public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2,
             int arg3) {
         firstItemIndex = firstVisiableItem;
         visibleLastIndex = firstVisiableItem + arg2 - 1;
         visibleItemCount = arg2;
         if(firstItemIndex == 1 && !isPush){
             setSelection(0);
         }
     }

     public void setSelectionfoot(){
         this.setSelection(visibleLastIndex - visibleItemCount + 1);
     }

     public void onScrollStateChanged(AbsListView arg0, int arg1) {

     }
     @Override
     public boolean onTouchEvent(MotionEvent event) {

         if (isRefreshable) {
             switch (event.getAction()) {
             case MotionEvent.ACTION_DOWN:
                 if (firstItemIndex == 0 && !isRecored) {
                     isRecored = true;
                     isPush = true;
                     startY = (int) event.getY();
                     Log.v(TAG, "在down时候记录当前位置‘");
                 }
                 break;
             case MotionEvent.ACTION_UP:
                 if (state != REFRESHING && state != LOADING) {
                     if (state == DONE) {
                         // 什么都不做
                     }
                     if (state == PULL_To_REFRESH) {
                         state = DONE;
                         changeHeaderViewByState();

                         Log.v(TAG, "由下拉刷新状态，到done状态");
                     }
                     if (state == RELEASE_To_REFRESH) {
                         state = REFRESHING;
                         changeHeaderViewByState();
                         onRefresh();

                         Log.v(TAG, "由松开刷新状态，到done状态");
                     }
                 }

                 isRecored = false;
                 isBack = false;

                 break;

             case MotionEvent.ACTION_MOVE:
                 int tempY = (int) event.getY();

                 if (!isRecored && firstItemIndex == 0) {
                     Log.v(TAG, "在move时候记录下位置");
                     isRecored = true;
                     startY = tempY;
                 }

                 if (state != REFRESHING && isRecored && state != LOADING) {

                     // 保证在设置padding的过程中，当前的位置一直是在head，否则如果当列表超出屏幕的话，当在上推的时候，列表会同时进行滚动

                     // 可以松手去刷新了
                     if (state == RELEASE_To_REFRESH) {

                         setSelection(0);

                         // 往上推了，推到了屏幕足够掩盖head的程度，但是还没有推到全部掩盖的地步
                         if (((tempY - startY) / RATIO < headContentHeight)
                                 && (tempY - startY) > 0) {
                             state = PULL_To_REFRESH;
                             changeHeaderViewByState();

                             Log.v(TAG, "由松开刷新状态转变到下拉刷新状态");
                         }
                         // 一下子推到顶了
                         else if (tempY - startY <= 0) {
                             state = DONE;
                             changeHeaderViewByState();

                             Log.v(TAG, "由松开刷新状态转变到done状态");
                         }
                         // 往下拉了，或者还没有上推到屏幕顶部掩盖head的地步
                         else {
                             // 不用进行特别的操作，只用更新paddingTop的值就行了
                         }
                     }
                     // 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态
                     if (state == PULL_To_REFRESH) {

                         setSelection(0);

                         // 下拉到可以进入RELEASE_TO_REFRESH的状态
                         if ((tempY - startY) / RATIO >= headContentHeight) {
                             state = RELEASE_To_REFRESH;
                             isBack = true;
                             changeHeaderViewByState();
                             Log.v(TAG, "由done或者下拉刷新状态转变到松开刷新");
                         }
                         // 上推到顶了
                         else if (tempY - startY <= 0) {
                             state = DONE;
                             changeHeaderViewByState();
                             isPush = false;
                             Log.v(TAG, "由DOne或者下拉刷新状态转变到done状态");
                         }
                     }

                     // done状态下
                     if (state == DONE) {
                         if (tempY - startY > 0) {
                             state = PULL_To_REFRESH;
                             changeHeaderViewByState();
                         }
                     }

                     // 更新headView的size
                     if (state == PULL_To_REFRESH) {
                         headView.setPadding(0, -1 * headContentHeight
                                 + (tempY - startY) / RATIO, 0, 0);

                     }

                     // 更新headView的paddingTop
                     if (state == RELEASE_To_REFRESH) {
                         headView.setPadding(0, (tempY - startY) / RATIO
                                 - headContentHeight, 0, 0);
                     }

                 }

                 break;
             }
         }

         return super.onTouchEvent(event);
     }

     // 当状态改变时候，调用该方法，以更新界面
     private void changeHeaderViewByState() {
         switch (state) {
         case RELEASE_To_REFRESH:
             arrowImageView.setVisibility(View.VISIBLE);
             progressBar.setVisibility(View.GONE);
             tipsTextview.setVisibility(View.VISIBLE);
             lastUpdatedTextView.setVisibility(View.VISIBLE);

             arrowImageView.clearAnimation();
             arrowImageView.startAnimation(animation);

             tipsTextview.setText(getResources().getString(R.string.release_to_refresh));

             Log.v(TAG, "当前状态，松开刷新");
             break;
         case PULL_To_REFRESH:
             progressBar.setVisibility(View.GONE);
             tipsTextview.setVisibility(View.VISIBLE);
             lastUpdatedTextView.setVisibility(View.VISIBLE);
             arrowImageView.clearAnimation();
             arrowImageView.setVisibility(View.VISIBLE);
             // 是由RELEASE_To_REFRESH状态转变来的
             if (isBack) {
                 isBack = false;
                 arrowImageView.clearAnimation();
                 arrowImageView.startAnimation(reverseAnimation);

                 tipsTextview.setText(getResources().getString(R.string.pull_to_refresh));
             } else {
                 tipsTextview.setText(getResources().getString(R.string.pull_to_refresh));
             }
             Log.v(TAG, "当前状态，下拉刷新");
             break;

         case REFRESHING:

             headView.setPadding(0, 0, 0, 0);

             progressBar.setVisibility(View.VISIBLE);
             arrowImageView.clearAnimation();
             arrowImageView.setVisibility(View.GONE);
             tipsTextview.setText(getResources().getString(R.string.refreshing));
             lastUpdatedTextView.setVisibility(View.VISIBLE);

             Log.v(TAG, "当前状态,正在刷新...");
             break;
         case DONE:
             headView.setPadding(0, -1 * headContentHeight, 0, 0);

             progressBar.setVisibility(View.GONE);
             arrowImageView.clearAnimation();
             arrowImageView.setImageResource(R.drawable.pulltorefresh);
             tipsTextview.setText(getResources().getString(R.string.pull_to_refresh));
             lastUpdatedTextView.setVisibility(View.VISIBLE);

             Log.v(TAG, "当前状态，done");
             break;
         }
     }

     public void setonRefreshListener(OnRefreshListener refreshListener) {
         this.refreshListener = refreshListener;
         isRefreshable = true;
     }

     public interface OnRefreshListener {
         public void onRefresh();
     }

     public void onRefreshComplete() {
         state = DONE;
         lastUpdatedTextView.setText(getResources().getString(R.string.updating) + new Date().toLocaleString());
         changeHeaderViewByState();
         invalidateViews();
         setSelection(0);
     }

     private void onRefresh() {
         if (refreshListener != null) {
             refreshListener.onRefresh();
         }
     }

     public void clickToRefresh(){
         state = REFRESHING;
         changeHeaderViewByState();
     }

     // 此方法直接照搬自网络上的一个下拉刷新的demo，此处是“估计”headView的width以及height
     private void measureView(View child) {
         ViewGroup.LayoutParams p = child.getLayoutParams();
         if (p == null) {
             p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                     ViewGroup.LayoutParams.WRAP_CONTENT);
         }
         int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0 + 0, p.width);
         int lpHeight = p.height;
         int childHeightSpec;
         if (lpHeight > 0) {
             childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight,
                     MeasureSpec.EXACTLY);
         } else {
             childHeightSpec = MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);
         }
         child.measure(childWidthSpec, childHeightSpec);
     }

     public void setAdapter(BaseAdapter adapter) {
         lastUpdatedTextView.setText(getResources().getString(R.string.updating) + new Date().toLocaleString());
         super.setAdapter(adapter);
     }
 }  

以上就是有下拉和上拉刷新功能的自定义的listview，下拉刷新头和上拉刷新的底部样式都可以自定义

这里给出我的下拉头布局和上拉底部布局，你们可以在此基础上进行修改自定义；

pulllist_head.xml 头布局

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ListView的头部 -->
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
     android:paddingTop="5dp"
     android:paddingBottom="5dp"
     android:background="#FFFFFFFF" >

     <!-- 内容 -->

     <RelativeLayout
         android:id="@+id/head_contentLayout"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:layout_marginTop="10dp"
         android:layout_marginBottom="10dp"
         android:paddingLeft="10dp" >

         <!-- 箭头图像、进度条 -->

         <FrameLayout
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_alignParentLeft="true"
             android:layout_centerVertical="true" >

             <!-- 箭头 -->

             <ImageView
                 android:id="@+id/head_arrowImageView"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_gravity="center"
                 android:src="@drawable/pulltorefresh" />

             <!-- 进度条 -->

             <ProgressBar
                 android:id="@+id/head_progressBar"
                 style="@android:style/Widget.ProgressBar.Small"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_gravity="center"
                 android:visibility="gone" />
         </FrameLayout>

         <!-- 提示、最近更新 -->

         <LinearLayout
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_centerHorizontal="true"
             android:gravity="center_horizontal"
             android:orientation="vertical" >

             <!-- 提示 -->

             <TextView
                 android:id="@+id/head_tipsTextView"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:textSize="16sp" />

             <!-- 最近更新 -->

             <TextView
                 android:id="@+id/head_lastUpdatedTextView"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:textSize="13sp" />
         </LinearLayout>
     </RelativeLayout>

 </LinearLayout>

底部布局：list_footview.xml

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/list_footview"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:background="@android:color/white"
     android:orientation="vertical" >

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerInParent="true"
         android:layout_centerVertical="true"
         android:layout_marginBottom="25dp"
         android:layout_marginTop="25dp"
         android:gravity="center"
         android:orientation="horizontal" >

         <TextView
             android:id="@+id/text_view"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:gravity="center"
             android:text="获取更多"
             android:textColor="@android:color/black"
             android:textSize="16sp" />

         <ProgressBar
             android:id="@+id/footer_progress"
             style="?android:attr/progressBarStyleSmall"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginLeft="3dp"
             android:visibility="gone" />
     </LinearLayout>

 </RelativeLayout>

ok这样一个自定义的下拉上拉刷新的listview就定义好了，可以在activity的布局文件中直接引用，并且像操纵listview那样使用

非常方便，这里也给出我使用的源码；

首先是主界面布局：main.xml

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

     <com.ryantang.pulllistview.RTPullListView
         android:id="@+id/pullListView"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content" />

 </LinearLayout>

主界面activity中使用源码：

 package com.ryantang.pulllistview;

 import java.util.ArrayList;
 import java.util.List;

 import android.app.Activity;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.ArrayAdapter;
 import android.widget.ProgressBar;
 import android.widget.RelativeLayout;

 import com.ryantang.pulllistview.RTPullListView.OnRefreshListener;

 /**
  * PullListView
  * @author Ryan
  *
  */
 public class RTPullListViewActivity extends Activity {
     private static final int INTERNET_FAILURE = -1;
     private static final int LOAD_SUCCESS = 1;
     private static final int LOAD_MORE_SUCCESS = 3;
     private static final int NO_MORE_INFO = 4;
     private static final int LOAD_NEW_INFO = 5;
     private RTPullListView pullListView;
     private ProgressBar moreProgressBar;
     private List<String> dataList;
     private ArrayAdapter<String> adapter;

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         pullListView = (RTPullListView) this.findViewById(R.id.pullListView);

         dataList = new ArrayList<String>();
         for (int i = 0; i < 5; i++) {
             dataList.add("Item data "+i);
         }
         adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, dataList);
         pullListView.setAdapter(adapter);

         //添加listview底部获取更多按钮（可自定义）
         LayoutInflater inflater = LayoutInflater.from(this);
         View view = inflater.inflate(R.layout.list_footview, null);
         RelativeLayout footerView =(RelativeLayout) view.findViewById(R.id.list_footview);
         moreProgressBar = (ProgressBar) view.findViewById(R.id.footer_progress);
         pullListView.addFooterView(footerView);

         //下拉刷新监听器
         pullListView.setonRefreshListener(new OnRefreshListener() {

             @Override
             public void onRefresh() {
                 new Thread(new Runnable() {

                     @Override
                     public void run() {
                         try {
                             Thread.sleep(2000);
                             dataList.clear();
                             for (int i = 0; i < 5; i++) {
                                 dataList.add("Item data "+i);
                             }
                             myHandler.sendEmptyMessage(LOAD_NEW_INFO);
                         } catch (InterruptedException e) {
                             e.printStackTrace();
                         }
                     }
                 }).start();
             }
         });

         //获取跟多监听器
         footerView.setOnClickListener(new OnClickListener() {//

             @Override
             public void onClick(View v) {

                 moreProgressBar.setVisibility(View.VISIBLE);

                 new Thread(new Runnable() {

                     @Override
                     public void run() {
                         try {
                             Thread.sleep(2000);
                             for (int i = 0; i < 5; i++) {
                                 dataList.add("New item data "+i);
                             }
                             myHandler.sendEmptyMessage(LOAD_MORE_SUCCESS);
                         } catch (InterruptedException e) {
                             e.printStackTrace();
                         }
                     }
                 }).start();
             }
         });
     }

     //结果处理
     private Handler myHandler = new Handler(){

         @Override
         public void handleMessage(Message msg) {
             super.handleMessage(msg);
             switch (msg.what) {
             case LOAD_MORE_SUCCESS:
                 moreProgressBar.setVisibility(View.GONE);
                 adapter.notifyDataSetChanged();
                 pullListView.setSelectionfoot();
                 break;

             case LOAD_NEW_INFO:
                 adapter.notifyDataSetChanged();
                 pullListView.onRefreshComplete();
                 break;
             default:
                 break;
             }
         }

     };
 }

效果图如下：