基于Android的计步器(Pedometer)的讲解(六)——ListView下拉刷新页面

最新推荐文章于 2022-05-31 15:25:51 发布

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最新推荐文章于 2022-05-31 15:25:51 发布

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分类专栏： Android 文章标签： android 计步器 listview

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本文介绍了一种在Android应用中实现ListView下拉刷新的方法。通过监听手势和滚动状态，结合自定义视图和动画，实现了流畅的刷新体验。文中提供了完整的代码示例。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

计步器（Pedometer）整个项目的源代码，最近做了比较大的修改，可能以前下载的不能运行，感兴趣的朋友可以下载来看看(记得帮小弟在github打个星~)

https://github.com/296777513/pedometer

今天实现实现的下拉刷新的功能，先上几张效果图：

如图所示，今天就是要实现的这个效果

首先，分析ListView下拉刷新实现方式

1、需要添加顶部下拉加载页面

2、需要监听onScrollListener来判断当前是否显示在listview的最顶部

3、因为顶部下拉加载界面是跟随手势滑动状态不断改变界面显示的所以我们需要监听onTouch事件，来改变当前状态以及界面显示；

4、根据当前状态加载数据

一下是ReFlashListView下拉刷新类的代码

package com.example.listviewfreshdemo1;

import java.text.SimpleDateFormat;
import java.util.Date;
import android.annotation.SuppressLint;
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.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;

public class ReFlashListView extends ListView implements OnScrollListener {
	private View header;// 顶部布局文件；
	int headerHeight;// 顶部布局文件的高度；
	int firstVisibleItem;// 当前第一个可见的item的位置；
	int scrollState;// listview 当前滚动状态；
	boolean isRemark;// 标记，当前是在listview最顶端摁下的；
	int startY;// 摁下时的Y值；

	int state;// 当前的状态；
	final int NONE = 0;// 正常状态；
	final int PULL = 1;// 提示下拉状态；
	final int RELESE = 2;// 提示释放状态；
	final int REFLASHING = 3;// 刷新状态；
	private IReflashListener iReflashListener;// 刷新数据的接口

	public ReFlashListView(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		initView(context);
	}

	public ReFlashListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		initView(context);
	}

	public ReFlashListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
		initView(context);
	}

	/**
	 * 初始化界面，添加顶部布局文件到 listview
	 * 
	 * @param context
	 */
	private void initView(Context context) {
		LayoutInflater inflater = LayoutInflater.from(context);
		header = inflater.inflate(R.layout.header, null);//加载顶部布局文件
		measureView(header);
		headerHeight = header.getMeasuredHeight();
		Log.i("tag", "headerHeight = " + headerHeight);
		topPadding(-headerHeight);
		this.addHeaderView(header);
		this.setOnScrollListener(this);
	}

	/**
	 * 通知父布局，占用的宽，高；
	 * 
	 * @param view
	 */
	private void measureView(View view) {
		ViewGroup.LayoutParams p = view.getLayoutParams();
		if (p == null) {
			p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
					ViewGroup.LayoutParams.WRAP_CONTENT);
		}
		int width = ViewGroup.getChildMeasureSpec(0, 0, p.width);
		int height;
		int tempHeight = p.height;
		if (tempHeight > 0) {
			height = MeasureSpec.makeMeasureSpec(tempHeight,
					MeasureSpec.EXACTLY);
		} else {
			height = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
		}
		view.measure(width, height);
	}

	/**
	 * 设置header 布局 上边距；
	 * 
	 * @param topPadding
	 */
	private void topPadding(int topPadding) {
		header.setPadding(header.getPaddingLeft(), topPadding,
				header.getPaddingRight(), header.getPaddingBottom());
		header.invalidate();
	}

	@Override
	public void onScroll(AbsListView view, int firstVisibleItem,
			int visibleItemCount, int totalItemCount) {
		this.firstVisibleItem = firstVisibleItem;
	}

	@Override
	public void onScrollStateChanged(AbsListView view, int scrollState) {
		this.scrollState = scrollState;
	}

	@SuppressLint("ClickableViewAccessibility")
	@Override
	public boolean onTouchEvent(MotionEvent ev) {
		// TODO Auto-generated method stub
		switch (ev.getAction()) {
		case MotionEvent.ACTION_DOWN:
			if (firstVisibleItem == 0) {
				isRemark = true;
				startY = (int) ev.getY();
			}
			break;

		case MotionEvent.ACTION_MOVE:
			onMove(ev);
			break;
		case MotionEvent.ACTION_UP:
			if (state == RELESE) {
				state = REFLASHING;
				// 加载最新数据；
				reflashViewByState();
				iReflashListener.onReflash();
			} else if (state == PULL) {
				state = NONE;
				isRemark = false;
				reflashViewByState();
			}
			break;
		}
		return super.onTouchEvent(ev);
	}

	/**
	 * 判断移动过程操作；
	 * 
	 * @param ev
	 */
	private void onMove(MotionEvent ev) {
		if (!isRemark) {
			return;
		}
		int tempY = (int) ev.getY();
		int space = tempY - startY;
		int topPadding = space - headerHeight;
		switch (state) {
		case NONE:
			if (space > 0) {
				state = PULL;
				reflashViewByState();
			}
			break;
		case PULL:
			topPadding(topPadding);
			if (space > headerHeight + 30
					&& scrollState == SCROLL_STATE_TOUCH_SCROLL) {
				state = RELESE;
				reflashViewByState();
			}
			break;
		case RELESE:
			topPadding(topPadding);
			if (space < headerHeight + 30) {
				state = PULL;
				reflashViewByState();
			} else if (space <= 0) {
				state = NONE;
				isRemark = false;
				reflashViewByState();
			}
			break;
		}
	}

	/**
	 * 根据当前状态，改变界面显示；
	 */
	private void reflashViewByState() {
		TextView tip = (TextView) header.findViewById(R.id.tip);
		ImageView arrow = (ImageView) header.findViewById(R.id.arrow);
		ProgressBar progress = (ProgressBar) header.findViewById(R.id.progress);
		RotateAnimation anim = new RotateAnimation(0, 180,
				RotateAnimation.RELATIVE_TO_SELF, 0.5f,
				RotateAnimation.RELATIVE_TO_SELF, 0.5f);
		anim.setDuration(500);
		anim.setFillAfter(true);
		RotateAnimation anim1 = new RotateAnimation(180, 0,
				RotateAnimation.RELATIVE_TO_SELF, 0.5f,
				RotateAnimation.RELATIVE_TO_SELF, 0.5f);
		anim1.setDuration(500);
		anim1.setFillAfter(true);
		switch (state) {
		case NONE:
			arrow.clearAnimation();
			topPadding(-headerHeight);
			break;

		case PULL:
			arrow.setVisibility(View.VISIBLE);
			progress.setVisibility(View.GONE);
			tip.setText("下拉可以刷新！");
			arrow.clearAnimation();
			arrow.setAnimation(anim1);
			break;
		case RELESE:
			arrow.setVisibility(View.VISIBLE);
			progress.setVisibility(View.GONE);
			tip.setText("松开可以刷新！");
			arrow.clearAnimation();
			arrow.setAnimation(anim);
			break;
		case REFLASHING:
			topPadding(50);
			arrow.setVisibility(View.GONE);
			progress.setVisibility(View.VISIBLE);
			tip.setText("正在刷新...");
			arrow.clearAnimation();
			break;
		}
	}

	/**
	 * 获取完数据；
	 */
	public void reflashComplete() {
		state = NONE;
		isRemark = false;
		reflashViewByState();
		TextView lastupdatetime = (TextView) header
				.findViewById(R.id.freshTime);
		SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日 hh:mm:ss");
		Date date = new Date(System.currentTimeMillis());
		String time = format.format(date);
		lastupdatetime.setText(time);
	}

	public void setInterface(IReflashListener iReflashListener) {
		this.iReflashListener = iReflashListener;
	}

	/**
	 * 刷新数据接口
	 * 
	 * @author Administrator
	 */
	public interface IReflashListener {
		public void onReflash();
	}
}

实现刷新页面的测试类代码

package com.example.listviewfreshdemo1;

import java.util.ArrayList;
import java.util.List;
import com.example.listviewfreshdemo1.ReFlashListView.IReflashListener;
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;

public class FragmentPK_1 extends Fragment implements IReflashListener {
	private View view;
	private ReFlashListView myListView;
	private MyAdapter myAdapter;
	private List<User> users;

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {

		view = inflater.inflate(R.layout.pk_1, container, false);
		setData();
		showList();
		return view;
	}

	/**
	 * 通知界面显示
	 */
	private void showList() {
		if (myAdapter == null) {
			myListView = (ReFlashListView) view.findViewById(R.id.flashView);
			myAdapter = new MyAdapter(getActivity(), users, myListView);
			myListView.setAdapter(myAdapter);
			myListView.setInterface(this);
		} else {
			myAdapter.DataChanged(users);
		}
	}

	/**
	 * 设置数据
	 */
	private void setData() {
		users = new ArrayList<User>();
		for (int i = 0; i < 10; i++) {
			User user = new User();
			user.setName("old big: " + i);
			user.setInfo("坑爹:" + i);
			users.add(user);
		}
	}
	/**
	 * 设置刷新后的数据
	 */
	private void setReflashData() {
		for (int i = 0; i < 2; i++) {
			User user = new User();
			user.setName("这是重生的old big: " + i);
			user.setInfo("继续坑爹:" + i);
			users.add(0, user);
		}
		
	}
	@Override
	public void onReflash() {
		Handler handler = new Handler();
		handler.postDelayed(new Runnable() {
			
			@Override
			public void run() {
				//获取最新数据
				setReflashData();
				//通知界面显示
				showList();
				//通知listview 刷新数据完毕；
				myListView.reflashComplete();
				
			}

			
		}, 2000);

	}

}

这个例子的demo下载页面（0分下载，并且增加指示器随页面变化而改变）

http://download.youkuaiyun.com/detail/a296777513/8346699