下拉刷新-------
1.addHeaderView必须在setAdapter之前调用 2.将paddingTop设置一个headerView高度的负值去隐藏它 getHeight()和getMeasuredHeight()的区别： getMeasuredHeight():获取测量完的高度，只要在onMeasure方法执行完，就可以用 它获取到宽高，在自定义控件内部多使用这个 使用view.measure(0,0)方法可以主动通知系统去测量，然后就 可以直接使用它获取宽高 getHeight()：必须在onLayout方法执行完后，才能获得宽高 view.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() { @Override public void onGlobalLayout() { headerView.getViewTreeObserver().removeGlobalOnLayoutListener(this); int headerViewHeight = headerView.getHeight(); //直接可以获取宽高 } }); 3.setSelection(position);将对应位置的item放置到屏幕顶端
第一步：制作一个旋转的箭头动画indeterminate_drawable.xml
旋转360度
第二步：下拉加载布局文件layout_header.xml
第三步：上拉加载布局文件layout_footer.xml
第四步：自定义一个带下拉刷新，上拉加载的listView
package com.zaizai.dropdownrefresh.view; import java.text.SimpleDateFormat; import java.util.Date; import android.widget.AbsListView.OnScrollListener; import android.content.Context; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.animation.RotateAnimation; import android.widget.AbsListView; import android.widget.ImageView; import android.widget.ListView; import android.widget.ProgressBar; import android.widget.TextView; import com.zaizai.dropdownrefresh.R; public class RefreshListView extends ListView implements OnScrollListener { private View headerView;//headerView private ImageView ivArrow; private ProgressBar pbRotate; private TextView tvState, tvTime; private View footerView; private int footerViewHeight; private int headerViewHeight;//headerView高 private int downY;//按下时y坐标 private final int PULL_REFRESH = 0;//下拉刷新的状态 private final int RELEASE_REFRESH = 1;//松开刷新的状态 private final int REFRESHING = 2;//正在刷新的状态 private int currentState = PULL_REFRESH; private RotateAnimation upAnimation, downAnimation; private boolean isLoadingMore = false;//当前是否正在处于加载更多 public RefreshListView(Context context) { super(context); init(); } public RefreshListView(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init() { //设置滚动监听事件 setOnScrollListener(this); initHeaderView(); initRotateAnimation(); initFooterView(); } /** * 初始化headerView */ private void initHeaderView() { headerView = View.inflate(getContext(), R.layout.layout_header, null); ivArrow = (ImageView) headerView.findViewById(R.id.iv_arrow); pbRotate = (ProgressBar) headerView.findViewById(R.id.pb_rotate); tvState = (TextView) headerView.findViewById(R.id.tv_state); tvTime = (TextView) headerView.findViewById(R.id.tv_time); headerView.measure(0, 0);//主动通知系统去测量该view; headerViewHeight = headerView.getMeasuredHeight(); //获得View的高度 headerView.setPadding(0, -headerViewHeight, 0, 0); //将View隐藏，在下拉时在显示 //将其放在第一个view位置 addHeaderView(headerView); } /** * 初始化旋转动画 */ private void initRotateAnimation() { upAnimation = new RotateAnimation(0, -180, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); upAnimation.setDuration(300); upAnimation.setFillAfter(true); downAnimation = new RotateAnimation(-180, -360, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); downAnimation.setDuration(300); downAnimation.setFillAfter(true); } private void initFooterView() { footerView = View.inflate(getContext(), R.layout.layout_footer, null); footerView.measure(0, 0);//主动通知系统去测量该view; footerViewHeight = footerView.getMeasuredHeight(); //获得底部view的高度 footerView.setPadding(0, -footerViewHeight, 0, 0); //将其隐藏 addFooterView(footerView); //设置为最底部的View } @Override public boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: { //获得按下的Y值 downY = (int) ev.getY(); break; } case MotionEvent.ACTION_MOVE: { if (currentState == REFRESHING) { //正在加载数据未完成，此时拖动不处理 break; } //下拉的距离 int deltaY = (int) (ev.getY() - downY); int paddingTop = -headerViewHeight + deltaY; //下拉的距离大于0且第一个条目已经出现 if (paddingTop > -headerViewHeight && getFirstVisiblePosition() == 0) { /*根据下拉的距离重新定位headerView*/ headerView.setPadding(0, paddingTop, 0, 0); // Log.e("RefreshListView", "paddingTop: "+paddingTop); if (paddingTop >= 0 && currentState == PULL_REFRESH) { //从下拉刷新进入松开刷新状态 currentState = RELEASE_REFRESH; //更新headerView状态 refreshHeaderView(); } else if (paddingTop < 0 && currentState == RELEASE_REFRESH) { //进入下拉刷新状态 currentState = PULL_REFRESH; refreshHeaderView(); } return true;//拦截TouchMove。不让listview处理该次move事件,会造成listview无法滑动 } break; } case MotionEvent.ACTION_UP: { if (currentState == PULL_REFRESH) { //隐藏headerView headerView.setPadding(0, -headerViewHeight, 0, 0); } else if (currentState == RELEASE_REFRESH) { headerView.setPadding(0, 0, 0, 0); currentState = REFRESHING; refreshHeaderView(); if (listener != null) { listener.onPullRefresh(); } } break; } default: { break; } } return super.onTouchEvent(ev); } /** * 根据currentState来更新headerView状态 */ private void refreshHeaderView() { switch (currentState) { case PULL_REFRESH: tvState.setText("下拉刷新"); ivArrow.startAnimation(downAnimation); break; case RELEASE_REFRESH: tvState.setText("松开刷新"); ivArrow.startAnimation(upAnimation); break; case REFRESHING: ivArrow.clearAnimation();//因为向上的旋转动画有可能没有执行完 ivArrow.setVisibility(View.INVISIBLE); pbRotate.setVisibility(View.VISIBLE); tvState.setText("正在刷新..."); break; } } /** * 完成刷新操作，重置状态,在你获取完数据并更新完adater之后，去在UI线程中调用该方法 */ public void completeRefresh() { if (isLoadingMore) { //重置footerView状态 footerView.setPadding(0, -footerViewHeight, 0, 0); isLoadingMore = false; } else { //重置headerView状态 headerView.setPadding(0, -headerViewHeight, 0, 0); currentState = PULL_REFRESH; pbRotate.setVisibility(View.INVISIBLE); ivArrow.setVisibility(View.VISIBLE); tvState.setText("下拉刷新"); tvTime.setText("最后刷新：" + getCurrentTime()); } } /** * 获取当前系统时间，并格式化 * * @return */ private String getCurrentTime() { SimpleDateFormat format = new SimpleDateFormat("yy-MM-dd HH:mm:ss"); return format.format(new Date()); } private OnRefreshListener listener; public void setOnRefreshListener(OnRefreshListener listener) { this.listener = listener; } public interface OnRefreshListener { void onPullRefresh(); void onLoadingMore(); } /** * SCROLL_STATE_IDLE:闲置状态，就是手指松开 * SCROLL_STATE_TOUCH_SCROLL：手指触摸滑动，就是按着来滑动 * SCROLL_STATE_FLING：快速滑动后松开 */ @Override public void onScrollStateChanged(AbsListView view, int scrollState) { if (scrollState == OnScrollListener.SCROLL_STATE_IDLE && getLastVisiblePosition() == (getCount() - 1) && !isLoadingMore) { isLoadingMore = true; footerView.setPadding(0, 0, 0, 0);//显示出footerView setSelection(getCount());//让listview最后一条显示出来 if (listener != null) { listener.onLoadingMore(); } } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } } 第五步：自定义listView使用
package com.zaizai.dropdownrefresh; import android.os.Handler; import android.os.SystemClock; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.view.Window; import android.widget.BaseAdapter; import android.widget.TextView; import com.zaizai.dropdownrefresh.view.RefreshListView; import java.util.ArrayList; public class MainActivity extends AppCompatActivity { private RefreshListView refreshListView; private ArrayList list = new ArrayList (); private MyAdapter adapter; private Handler handler = new Handler() { public void handleMessage(android.os.Message msg) { //更新UI adapter.notifyDataSetChanged(); refreshListView.completeRefresh(); } ; }; @Override protected void onCreate(Bundle savedInstanceState) { requestWindowFeature(Window.FEATURE_NO_TITLE); super.onCreate(savedInstanceState); initView(); initData(); } private void initView() { setContentView(R.layout.activity_main); refreshListView = (RefreshListView) findViewById(R.id.refreshListView); } private void initData() { for (int i = 0; i < 15; i++) { list.add("listview原来的数据 - " + i); } // final View headerView = View.inflate(this, R.layout.layout_header, null); //第一种方法 // headerView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() { // @Override // public void onGlobalLayout() { // headerView.getViewTreeObserver().removeGlobalOnLayoutListener(this); // int headerViewHeight = headerView.getHeight(); // // // Log.e("MainActivity", "headerViewHeight: "+headerViewHeight); // headerView.setPadding(0, -headerViewHeight, 0, 0); // refreshListView.addHeaderView(headerView);// // } // }); //第二种方法 // headerView.measure(0, 0);//主动通知系统去测量 // int headerViewHeight = headerView.getMeasuredHeight(); // Log.e("MainActivity", "headerViewHeight: "+headerViewHeight); // headerView.setPadding(0, -headerViewHeight, 0, 0); // refreshListView.addHeaderView(headerView);// adapter = new MyAdapter(); refreshListView.setAdapter(adapter); refreshListView.setOnRefreshListener(new RefreshListView.OnRefreshListener() { @Override public void onPullRefresh() { //需要联网请求服务器的数据，然后更新UI requestDataFromServer(false); } @Override public void onLoadingMore() { requestDataFromServer(true); } }); } /** * 模拟向服务器请求数据 */ private void requestDataFromServer(final boolean isLoadingMore) { new Thread() { public void run() { SystemClock.sleep(3000);//模拟请求服务器的一个时间长度 if (isLoadingMore) { list.add("加载更多的数据-1"); list.add("加载更多的数据-2"); list.add("加载更多的数据-3"); } else { list.add(0, "下拉刷新的数据"); } //在UI线程更新UI handler.sendEmptyMessage(0); } ; }.start(); } class MyAdapter extends BaseAdapter { @Override public int getCount() { return list.size(); } @Override public Object getItem(int position) { return null; } @Override public long getItemId(int position) { return 0; } @Override public View getView(int position, View convertView, ViewGroup parent) { TextView textView = new TextView(MainActivity.this); textView.setPadding(20, 20, 20, 20); textView.setTextSize(18); textView.setText(list.get(position)); return textView; } } }