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：