Android常用控件之下拉刷新Wifi列表

有些列表信息需要手动去更新，此时比较常用的就是下拉刷新列表，在这里就使用下拉列表来刷新当前Wifi信息

目录结构

界面

      

      

关键代码

下拉列表类

package com.example.dropdownrefresh.ui;

import java.text.SimpleDateFormat;
import java.util.Date;

import com.example.dropdownrefresh.R;

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;

/**
 * 下拉列表类
 * @author Administrator
 *
 */
public class DropdownListView extends ListView implements OnScrollListener {

	private static final String TAG = "listview";

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

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

	private void init(Context context) {
		setCacheColorHint(context.getResources().getColor(R.color.transparent));
		inflater = LayoutInflater.from(context);

		headView = (LinearLayout) inflater.inflate(R.layout.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();

		Log.v("size", "width:" + headContentWidth + " height:"
				+ headContentHeight);

		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;
	}

	@Override
	public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2,
			int arg3) {
		// TODO Auto-generated method stub
		firstItemIndex = firstVisiableItem;
	}

	@Override
	public void onScrollStateChanged(AbsListView view, int scrollState) {
		// TODO Auto-generated method stub

	}

	public boolean onTouchEvent(MotionEvent event) {

		if (isRefreshable) {
			switch (event.getAction()) {
			case MotionEvent.ACTION_DOWN:
				if (firstItemIndex == 0 && !isRecored) {
					isRecored = 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();

							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("松开刷新");

			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("下拉刷新");
			} else {
				tipsTextview.setText("下拉刷新");
			}
			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("正在刷新...");
			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.arrow);
			tipsTextview.setText("下拉刷新");
			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;
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		lastUpdatedTextView.setText("最近更新:" + sdf.format(new Date()));
		changeHeaderViewByState();
	}

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

	/**
	 * 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
	 * @param child
	 */
	private void measureView(View child) {
		ViewGroup.LayoutParams p = child.getLayoutParams();
		if (p == null) {
			p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_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) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		lastUpdatedTextView.setText("最近更新:" + sdf.format(new Date()));
		super.setAdapter(adapter);
	}
}

main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/bg"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <com.example.dropdownrefresh.ui.DropdownListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:cacheColorHint="#00000000"
        android:childDivider="@drawable/list_driver"
        android:divider="@drawable/list_driver" />

</LinearLayout>

下拉头的布局head.xml

<?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" >

    <!-- 内容 -->

    <RelativeLayout
        android:id="@+id/head_contentLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingLeft="30dp" >

        <!-- 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:contentDescription="@null"
                android:src="@drawable/arrow" />

            <!-- 进度条 -->

            <ProgressBar
                android:id="@+id/head_progressBar"
                style="?android:attr/progressBarStyleSmall"
                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:text="下拉刷新"
                android:textColor="@color/white"
                android:textSize="20sp" />

            <!-- 最近更新 -->

            <TextView
                android:id="@+id/head_lastUpdatedTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="上次更新"
                android:textColor="@color/gold"
                android:textSize="12sp" />
        </LinearLayout>
    </RelativeLayout>

</LinearLayout>

下拉列表松开后需要扫描Wifi，再刷新列表

package com.example.dropdownrefresh;

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

import android.app.Activity;
import android.net.wifi.ScanResult;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.example.dropdownrefresh.ui.DropdownListView;
import com.example.dropdownrefresh.ui.DropdownListView.OnRefreshListener;
import com.example.dropdownrefresh.utils.WifiAdmin;

/**
 * 使用下拉刷新搜索wifi
 * @author Administrator
 *
 */
public class MainActivity extends Activity {

	WifiAdmin wifiAdmin = null;
	private ArrayList<HashMap<String, String>> list;
	private BaseAdapter adapter;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		wifiAdmin = new WifiAdmin(this);
		list = new ArrayList<HashMap<String, String>>();
		RefreshList();

		final DropdownListView listView = (DropdownListView) findViewById(R.id.listView);
		adapter = new BaseAdapter() {
			public View getView(int position, View convertView, ViewGroup parent) {
				LinearLayout layout = new LinearLayout(getApplicationContext());
				layout.setOrientation(LinearLayout.VERTICAL);  //垂直布局
				HashMap<String, String> map = list.get(position);
				TextView txtName = new TextView(getApplicationContext());
				TextView txtSignal = new TextView(getApplicationContext());
				txtName.setText(map.get("wifi_name"));
				txtSignal.setText(map.get("wifi_signal"));
				layout.addView(txtName);
				layout.addView(txtSignal);
				return layout;
			}

			public long getItemId(int position) {
				return 0;
			}

			public Object getItem(int position) {
				return null;
			}

			public int getCount() {
				return list.size();
			}
		};
		listView.setAdapter(adapter);

		listView.setonRefreshListener(new OnRefreshListener() {
			public void onRefresh() {
				new AsyncTask<Void, Void, Void>() {
					protected Void doInBackground(Void... params) {
						try {
							Thread.sleep(1000);
						} catch (Exception e) {
							e.printStackTrace();
						}
						list.clear();
						RefreshList();
						return null;
					}

					@Override
					protected void onPostExecute(Void result) {
						adapter.notifyDataSetChanged();
						listView.onRefreshComplete();
					}

				}.execute(null, null, null);
			}
		});
	}

	private void RefreshList(){
		wifiAdmin.startScan(); // 扫描wifi热点，前提是wifi已经打开
		List<ScanResult> wifiList = wifiAdmin.getWifiList();
		for (int index = 0; index < wifiList.size(); index++) {
			HashMap<String, String> map = new HashMap<String, String>();
			map.put("wifi_name", (wifiList.get(index)).SSID);
			map.put("wifi_signal", "signal: "
					+ (-(wifiList.get(index)).level) + "%");
			list.add(map);
		}
	}
}

相关代码：http://download.csdn.net/detail/deng0zhaotai/7969215

时间： 2024-08-06 19:05:45

Android常用控件之下拉刷新Wifi列表的相关文章

android控件 下拉刷新pulltorefresh

外国人写的下拉刷新控件,我把他下载下来放在网盘,有时候访问不了github 支持各种控件下拉刷新 ListView.ViewPager.WevView.ExpandableListView.GridView.(Horizontal )ScrollView.Fragment上下左右拉动刷新,比下面johannilsson那个只支持ListView的强大的多.并且他实现的下拉刷新ListView在item不足一屏情况下也不会显示刷新提示,体验更好. 国内网盘地址:http://www.400gb.c

Android常用控件：进度条

各种进度条属于 ProgressBar的子类 Sytle: 水平风格:Horizontal小风格:Small大风格:Large反向风格:Inverse小反向风格:Small.Inverse大反向风格:Large.Inverse 设置style:   style="?android:attr/progressBarStyle..." 主要属性:最大值:max当前进度:progress次要进度值:SecondaryProgress --效果类似于看电影那些缓冲 判断进度条是转圈还是水平的方

android常用控件

在 Android 中使用各种控件(View) DatePicker - 日期选择控件 TimePicker - 时间选择控件 ToggleButton - 双状态按钮控件 EditText - 可编辑文本控件 ProgressBar - 进度条控件 SeekBar - 可拖动的进度条控件 AutoCompleteTextView - 支持自动完成功能的可编辑文本控件 MultiAutoCompleteTextView - 支持自动完成功能的可编辑文本控件,允许输入多值(多值之间会自动地用指定的

Android 常用控件接口监听

Android控件监听方面,用接口实现监听是最好的,在Android 本身就提供了各种控件监听接口,我们只要按照这样实现,看起来代码会很整洁.实现的效果也是很好的,下面我列举了常用控件的接口监听,layout ,checkbox,RadioGroup,以及listview的单击或者长按监听.下面请看代码,有注释. 本文项目源码地址: 点击此处下载 转载请注明出处: http://blog.csdn.net/qq_16064871 package com.example.impletedemo;

Android常用控件及对应Robotium API

最近发现Android控件不熟悉,看Robotium的API都费劲. 常用Android控件: 控件类型 描述 相关类 Button 按钮,可以被用户按下或点击,以执行?个动作 Button Text field 可编辑的文本区域,可以使用AutoCompleteTextView创建一个带有自动完成功能的编辑文本域 EditText,AutoCompleteTextView Checkbox 复选框,?个可以由用户切换的ON/OFF开关.当提供给用户?组不互斥的可选项时,你应该使用复选框 Che

C#自定义用户控件之下拉框

WebForm中,若一个asp页面中需要有很多个DropDownList控件的话,在后台即需写很多的绑定数据源方法,代码量较多且不易维护:然后咱自己就写了个用户自定义的控件,便于重用:但所牺牲的即是程序上的效率:话不多说,直接上代码: 控件源代码: <%@ Control Language="C#" AutoEventWireup="true" CodeBehind="WUCDropDownList.ascx.cs" Inherits=&q

Android常用控件之AutoCompleteTextView、Spinner

概述 1.AutoCompleteTextView:相对于普通的TextView,AutoCompleteTextView的特点是可以自动提示文本,它可以通过SetAdapter()方法加载适配器. 2.Spinner:一种下拉列表. 知识内容 AutoCompletedTextView 布局文件 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="

Android常用控件之GridView与ExpandableListView的用法

概述 1.GridView:与ListView相比,可以显示多列,xml布局时其属性numColumns可以设置显示的列数. 2.ExpandableListView:与ListView相比,可以让每一列单元都拥有子列表. 内容 GridView 显示3列和多行的图片以及名称 布局 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://sc

android常用控件纪录

<?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:orien