来源: 互联网  发布时间: 2014-02-18

下拉刷新功能

参照别人的代码，然后根据需求，拉过来的，很实用

 

1。首先创建一个头部xml文件：

<?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:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:id="@+id/head_contentLayout"
  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:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_gravity="center"
  android:src="/blog_article/@drawable/pull_down_arrow/index.html"
  android:id="@+id/head_arrowImageView"
  />
  
  <!-- 进度条 -->
  <ProgressBar
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  
  android:layout_gravity="center"
  android:id="@+id/head_progressBar"
  
  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:orientation="vertical"
  android:gravity="center_horizontal"
  >
  
  <!-- 提示 -->
  <TextView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="下拉刷新"
  android:textColor="@color/white"
  android:textSize="20sp"
  android:id="@+id/head_tipsTextView"
  />
  
  <!-- 最近更新 -->
  <TextView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:id="@+id/head_lastUpdatedTextView"
  android:text="上次更新"
  android:textColor="@color/gold"
  android:textSize="10sp"
  />
  
  </LinearLayout>
  
  
  </RelativeLayout>
  
  
</LinearLayout>

 

 

2.然后写一个class：

package com.laohuai.appdemo.customui.ui;

import java.util.Date;

import com.laohuai.appdemo.customui.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.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MyListView 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 MyListView(Context context) {
		super(context);
		init(context);
	}

	public MyListView(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;
	}

	public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2,
			int arg3) {
		firstItemIndex = firstVisiableItem;
	}

	public void onScrollStateChanged(AbsListView arg0, int arg1) {
	}

	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.pull_down_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;
		lastUpdatedTextView.setText("最近更新:" + new Date().toLocaleString());
		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
	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("最近更新:" + new Date().toLocaleString());
		super.setAdapter(adapter);
	}

}

 

 

3.在main.xml 中调用上面的这个class：

<?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" 
    android:background="#FFFFFF">
    
    <com.laohuai.appdemo.customui.ui.MyListView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/listView"
    android:listSelector="@android:color/transparent"
    />
    
</LinearLayout>

 

 

4.实现Activity：

package com.laohuai.appdemo.customui;

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

import com.laohuai.appdemo.customui.ui.MyListView;
import com.laohuai.appdemo.customui.ui.MyListView.OnRefreshListener;

import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class MainActivity extends Activity {
	HashMap<String, Object> maps;
	MyListView listView;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		listView = (MyListView) findViewById(R.id.listView);
		getData();
	}

	private void getData() {
		List<HashMap<String, Object>> lists = new ArrayList<HashMap<String, Object>>();

		for (int i = 0; i < 40; i++) {

			maps = new HashMap<String, Object>();
			maps.put("test", "搞定了没有啊");

			lists.add(maps);
		}
		final ListAdapter adapter = new ListAdapter(MainActivity.this, lists);
		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();
						}
						maps.get("刷新后添加的内容");
						return null;
					}

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

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

	class ListAdapter extends BaseAdapter {

		private Context mContext;
		private List<HashMap<String, Object>> data;

		public ListAdapter(Context mContext, List<HashMap<String, Object>> data) {
			super();
			this.mContext = mContext;
			this.data = data;
		}

		public int getCount() {
			// TODO Auto-generated method stub
			return data.size();
		}

		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		public View getView(int position, View convertView, ViewGroup parent) {
			TextView tv = new TextView(getApplicationContext());
			tv.setText((String)data.get(position).get("test"));
			Resources rs = getResources();
			tv.setTextColor(rs.getColor(R.color.white));
			return tv;
		}

	}
}

 

    

    来源: 互联网  发布时间: 2014-02-18

你真的会用AsyncTask吗
一个典型的AsyncTask应用

public class DialogTestActivity extends Activity {
	private Button button1;
	private Task task;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		this.button1 = (Button) findViewById(R.id.button1);
		button1.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View v) {
				if (task != null && task.getStatus() == AsyncTask.Status.RUNNING) {
					Toast.makeText(DialogTestActivity.this, "task 正在运行", Toast.LENGTH_SHORT).show();
					//task.cancel(true);  //  如果Task还在运行，则先取消它
					//task = null;
				} else {
					task = new Task();
					task.execute();
				}
			}
		});
	}

	@Override
	protected void onDestroy() {
		super.onDestroy();
		// 用户按回退的时候要取消正在进行的任务
		task.cancel(true);
	}

	private class Task extends AsyncTask<Void, Void, Void> {
		
		@Override
		protected void onPreExecute() {
			super.onPreExecute();
			Toast.makeText(DialogTestActivity.this, "task 开始运行", Toast.LENGTH_SHORT).show();
		}
		
		@Override
		protected Void doInBackground(Void... params) {
			try {
				// 模拟耗时操作 比如网络连接等
				Thread.sleep(5000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			// 判断如果task已经cancel就没有必须继续进行下面的操作
			if (!isCancelled()) {
				System.out.println("task 如果被cancel,就不会显示");
			}
			return null;
		}

		@Override
		protected void onPostExecute(Void result) {
			super.onPostExecute(result);
			Toast.makeText(DialogTestActivity.this, "task 完成", Toast.LENGTH_SHORT).show();
			// 所有调用当前context的对象要注意判断activity是否还存在
			// 典型的比如弹窗
			if (!isFinishing()) {
				try {
					createAlertDialog().show();
				} catch (Exception e) {
				}
			}
		}

		@Override
		protected void onCancelled() {
			super.onCancelled();
			System.out.println("task 取消");
		}

	}

	private AlertDialog createAlertDialog() {
		return new AlertDialog.Builder(DialogTestActivity.this).setTitle("fadfasdf")
				.setPositiveButton("OK", new DialogInterface.OnClickListener() {
					public void onClick(DialogInterface dialog, int whichButton) {

					}
				}).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
					public void onClick(DialogInterface dialog, int whichButton) {

					}
				}).create();
	}
}

    

    来源: 互联网  发布时间: 2014-02-18

wap开发中中文问题的解决
下面这句话是从网上摘录的，仅供参考的：
JSP中中文的解决：
中国移动加入以下几句后，页面中可以直接写中文，不用转换，提交的中文直接request.getParameter("")获得，不用转换
<%@ page contentType="text/vnd.wap.wml;charset=gb2312"%>
<%response.setContentType("text/vnd.wap.wml;charset=UTF-8");%>
<%request.setCharacterEncoding("UTF-8");%>
中国联通加入以下几句后，页面中可以直接写中文，不用转换，提交的中文直接request.getParameter("")获得，不用转换
<%@ page contentType="text/vnd.wap.wml;charset=gb2312"%>
<%request.setCharacterEncoding("UTF-8");%>
操作系统win2000,Web Server resin(或tomcat)
都是从实践中摸索出来的，业务已上线，没问题。

本人：
（1）在wml文件中定义为：
<?xml version="1.0" encoding="UTF-8"?>
（2）对提交数据采用post传递
<go href="/wapapp/servlet_wap/index.html" method="post">
<!-- go href="/servlet/wap86test/index.html"  -->
<postfield name="serviceID" value="0002"/>
<postfield name="phone" value="$(phone:e)"/>
<postfield name="passwd" value="$(passwd:e)"/>
</go>
（3）后台转换
移动——>
在servlet里面的doget和dopost方法设置
request.setCharacterEncoding("UTF-8");
response.setContentType(Const.CONTENT_TYPE);//Const.CONTENT_TYPE为：text/vnd.wap.wml;charset=UTF-8
①post提交处理表单：
一般都是直接request.getParameter("xxx")取过来的就是中文了，不需要再进行转码；
如增加成员
增加成员的post代码为：
<do type="accept" label="确定"><go href="/wapapp/servlet_wap/index.html" method="post"  >
<postfield name="serviceID" value="0207"/>
<postfield name="groupname" value="按时的发射点222"/>
<postfield name="groupcode" value="4"/>
<postfield name="aphone" value="$aphone"/>
<postfield name="aname" value="$(aname:e)"/>
</go></do>
在处理编号为”0207“的程序块中，对获得的参数是这样来处理的
String groupcode = request.getParameter("groupcode");
String groupName = request.getParameter("groupname");
String ctcPhone = request.getParameter("aphone");
String ctcName = request.getParameter("aname");
ctcName = ctcName.replaceAll(" ", "");
ctcName = ctcName.replaceAll("　", "");
if (!UserType.equals(SysChinaMobile)) {//移动的话直接getparameter的就是中文，而联通的却不是，所以需要转码
    try {
          groupName = WapUtil.decode(groupName, "UTF-8");
          ctcName = WapUtil.decode(ctcName, "UTF-8");
         } catch (Exception e) {
           e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
           out.println(returnPrevPage(strErrosOnServerCallAdmin));
          }
}
②get提交的url参数：
如果是通过get方式，或者是通过url来传递参数的话就不能用decode这个方法来实现转码,而是用togbk这个方法来实现；
而且如果是在servlet里面打印wml页面，码制转换也只能用togbk这个方法；
如：显示个组信息首页面
请求显示修改组的页面url为：/wapapp/servlet_wap?serviceID=0212&groupcode=6&groupname=%B0%B4%CA%B1%B5%C4%B7%A8333
在处理编号为”0212“的程序块中，对获得的参数是这样来处理的
String groupcode = request.getParameter("groupcode");
String groupname = request.getParameter("groupname");
try {
        groupname = WapUtil.togbk(groupname);
        groupcode = WapUtil.togbk(groupcode);
}catch (Exception e) {
         e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
         out.println(returnPrevPage(strErrosOnServerCallAdmin));
}

联通——>
在servlet里面的doget和dopost方法设置
response.setContentType(Const.CONTENT_TYPE);//Const.CONTENT_TYPE为：text/vnd.wap.wml;charset=UTF-8
①post提交处理表单：
需要调用decode方法进行转码；
②get提交的url参数：
需要调用togbk方法进行转码

思考：也许这不是联通与移动的问题，也许是tomcat在不同操作系统上的原因导致；

Waputil中最重要的几个方法：
WapUtil.toUrl(/blog_article/String gbkStr/index.html) :如果有中文参数，需要用此方法转换
WapUtil.gbk2unicode(String gbkStr):将中文转成utf-8格式的文字，显示在页面上；
WapUtil.togbk(String Utfstr)：将utf格式的文字转成gbk格式，用于后台处理；
WapUtil.decode(String s, String encoding)：将指定码制格式的文字转成gbk格式，用于后台处理；