使用谷歌提供的SwipeRefreshLayout下拉控件,并自定义实现下拉加载的功能
package com.loaderman.swiperefreshdemo; import android.os.Bundle; import android.os.Handler; import android.support.v4.widget.SwipeRefreshLayout; import android.support.v7.app.AppCompatActivity; import android.view.Gravity; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.loaderman.swiperefreshdemo.view.SwipeRefreshView; import java.util.ArrayList; import java.util.List; import java.util.Random; /** * 使用谷歌提供的SwipeRefreshLayout下拉控件进行下拉刷新 */ public class MainActivity extends AppCompatActivity { private List<String> mList; private int mCount; private StringAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final SwipeRefreshView swipeRefreshView = (SwipeRefreshView) findViewById(R.id.srl); ListView listView = (ListView) findViewById(R.id.lv); // 设置适配器数据 mList = new ArrayList<>(); for (int i = 0; i < 30; i++) { mList.add("我是天才" + i + "号"); mCount++; } mAdapter = new StringAdapter(); listView.setAdapter(mAdapter); // 不能在onCreate中设置,这个表示当前是刷新状态,如果一进来就是刷新状态,SwipeRefreshLayout会屏蔽掉下拉事件 //swipeRefreshLayout.setRefreshing(true); // 设置颜色属性的时候一定要注意是引用了资源文件还是直接设置16进制的颜色,因为都是int值容易搞混 // 设置下拉进度的背景颜色,默认就是白色的 swipeRefreshView.setProgressBackgroundColorSchemeResource(android.R.color.white); // 设置下拉进度的主题颜色 swipeRefreshView.setColorSchemeResources(R.color.colorAccent, R.color.colorPrimary, R.color.colorPrimaryDark); // 下拉时触发SwipeRefreshLayout的下拉动画,动画完毕之后就会回调这个方法 swipeRefreshView.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() { @Override public void onRefresh() { // 开始刷新,设置当前为刷新状态 //swipeRefreshLayout.setRefreshing(true); // 这里是主线程 // 一些比较耗时的操作,比如联网获取数据,需要放到子线程去执行 // TODO 获取数据 final Random random = new Random(); new Handler().postDelayed(new Runnable() { @Override public void run() { mList.add(0, "我是天才" + random.nextInt(100) + "号"); mAdapter.notifyDataSetChanged(); Toast.makeText(MainActivity.this, "刷新了一条数据", Toast.LENGTH_SHORT).show(); // 加载完数据设置为不刷新状态,将下拉进度收起来 swipeRefreshView.setRefreshing(false); } }, 1200); // System.out.println(Thread.currentThread().getName()); // 这个不能写在外边,不然会直接收起来 //swipeRefreshLayout.setRefreshing(false); } }); // 设置下拉加载更多 swipeRefreshView.setOnLoadListener(new SwipeRefreshView.OnLoadListener() { @Override public void onLoad() { new Handler().postDelayed(new Runnable() { @Override public void run() { // 添加数据 for (int i = 30; i < 35; i++) { mList.add("我是天才" + i+ "号"); // 这里要放在里面刷新,放在外面会导致刷新的进度条卡住 mAdapter.notifyDataSetChanged(); } Toast.makeText(MainActivity.this, "加载了" + 5 + "条数据", Toast.LENGTH_SHORT).show(); // 加载完数据设置为不加载状态,将加载进度收起来 swipeRefreshView.setLoading(false); } }, 1200); } }); } /** * 适配器 */ private class StringAdapter extends BaseAdapter { @Override public int getCount() { return mList.size(); } @Override public Object getItem(int position) { return mList.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { if (convertView == null) { convertView = View.inflate(MainActivity.this, android.R.layout.simple_list_item_1, null); } TextView tv = (TextView) convertView; tv.setGravity(Gravity.CENTER); tv.setPadding(0, 20, 0, 20); tv.setText(mList.get(position)); return convertView; } } }
package com.loaderman.swiperefreshdemo.view; import android.content.Context; import android.support.v4.widget.SwipeRefreshLayout; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.widget.AbsListView; import android.widget.ListView; import com.loaderman.swiperefreshdemo.R; /** * 自定义View继承SwipeRefreshLayout,添加上拉加载更多的布局属性 * Created by Pinger on 2016/9/26. */ public class SwipeRefreshView extends SwipeRefreshLayout { private final int mScaledTouchSlop; private final View mFooterView; private ListView mListView; private OnLoadListener mOnLoadListener; /** * 正在加载状态 */ private boolean isLoading; public SwipeRefreshView(Context context, AttributeSet attrs) { super(context, attrs); // 填充底部加载布局 mFooterView = View.inflate(context, R.layout.view_footer, null); // 表示控件移动的最小距离,手移动的距离大于这个距离才能拖动控件 mScaledTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop(); System.out.println("====" + mScaledTouchSlop); } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); // 获取ListView,设置ListView的布局位置 if (mListView == null) { // 判断容器有多少个孩子 if (getChildCount() > 0) { // 判断第一个孩子是不是ListView if (getChildAt(0) instanceof ListView) { // 创建ListView对象 mListView = (ListView) getChildAt(0); // 设置ListView的滑动监听 setListViewOnScroll(); } } } } /** * 在分发事件的时候处理子控件的触摸事件 * * @param ev * @return */ private float mDownY, mUpY; @Override public boolean dispatchTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: // 移动的起点 mDownY = ev.getY(); break; case MotionEvent.ACTION_MOVE: // 移动过程中判断时候能下拉加载更多 if (canLoadMore()) { // 加载数据 loadData(); } break; case MotionEvent.ACTION_UP: // 移动的终点 mUpY = getY(); break; } return super.dispatchTouchEvent(ev); } /** * 判断是否满足加载更多条件 * * @return */ private boolean canLoadMore() { // 1. 是上拉状态 boolean condition1 = (mDownY - mUpY) >= mScaledTouchSlop; if (condition1) { System.out.println("是上拉状态"); } // 2. 当前页面可见的item是最后一个条目 boolean condition2 = false; if (mListView != null && mListView.getAdapter() != null) { condition2 = mListView.getLastVisiblePosition() == (mListView.getAdapter().getCount() - 1); } if (condition2) { System.out.println("是最后一个条目"); } // 3. 正在加载状态 boolean condition3 = !isLoading; if (condition3) { System.out.println("不是正在加载状态"); } return condition1 && condition2 && condition3; } /** * 处理加载数据的逻辑 */ private void loadData() { System.out.println("加载数据..."); if (mOnLoadListener != null) { // 设置加载状态,让布局显示出来 setLoading(true); mOnLoadListener.onLoad(); } } /** * 设置加载状态,是否加载传入boolean值进行判断 * * @param loading */ public void setLoading(boolean loading) { // 修改当前的状态 isLoading = loading; if (isLoading) { // 显示布局 mListView.addFooterView(mFooterView); } else { // 隐藏布局 // mListView.removeFooterView(mFooterView); // 重置滑动的坐标 mDownY = 0; mUpY = 0; } } /** * 设置ListView的滑动监听 */ private void setListViewOnScroll() { mListView.setOnScrollListener(new AbsListView.OnScrollListener() { @Override public void onScrollStateChanged(AbsListView view, int scrollState) { // 移动过程中判断时候能下拉加载更多 if (canLoadMore()) { // 加载数据 loadData(); } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } }); } /** * 上拉加载的接口回调 */ public interface OnLoadListener { void onLoad(); } public void setOnLoadListener(OnLoadListener listener) { this.mOnLoadListener = listener; } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.pinger.swiperefreshdemo.MainActivity"> <!--使用谷歌官方的下拉刷新组件,只有下拉刷新功能--> <!-- <android.support.v4.widget.SwipeRefreshLayout android:id="@+id/srl" android:layout_width="match_parent" android:layout_height="match_parent"> <ListView android:id="@+id/lv" android:layout_width="match_parent" android:layout_height="match_parent"/> </android.support.v4.widget.SwipeRefreshLayout> --> <!--自定义View实现SwipeRefreshLayout,添加上拉加载更多的功能--> <com.loaderman.swiperefreshdemo.view.SwipeRefreshView android:id="@+id/srl" android:layout_width="match_parent" android:layout_height="match_parent"> <ListView android:id="@+id/lv" android:layout_width="match_parent" android:layout_height="match_parent"/> </com.loaderman.swiperefreshdemo.view.SwipeRefreshView> </RelativeLayout>
view-footer.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <RelativeLayout android:layout_width="match_parent" android:layout_height="50dp"> <ProgressBar android:id="@+id/load_progress" android:layout_width="25dp" android:layout_height="25dp" android:layout_centerVertical="true" android:layout_marginLeft="30dp"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:text="正在努力加载中..." android:textColor="@android:color/holo_red_dark" android:textSize="16sp"/> </RelativeLayout> </RelativeLayout>
效果图:
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