android 获取系统自带通讯录 示例源码下载

视频压缩

电商模版代码

该资源基于RTKLIB，整理了相对定位中调用的函数及公式，从读文件到解算结果的步骤，包括文件读取、计算基站位置、卫星位置、双差、卡尔曼滤波、模糊度估计等的原理与公式。

【实例简介】

一、ExpandableListView介绍 　　　　一个垂直滚动的显示两个级别（Child,Group）列表项的视图，列表项来自ExpandableListAdapter 。组可以单独展开。 　　1.重要方法 　　　　　　expandGroup(int groupPos) :在分组列表视图中展开一组，　　　　　　setSelectedGroup(int groupPosition) ：设置选择指定的组。　　　　　　setSelectedChild(int groupPosition, int childPosition, boolean shouldExpandGroup) ：设置选择指定的子项。　　　　　　getPackedPositionGroup(long packedPosition) ：返回所选择的组　　　　　　getPackedPositionForChild(int groupPosition, int childPosition) ：返回所选择的子项　　　　　　getPackedPositionType(long packedPosition) ：返回所选择项的类型（Child,Group）　　　　　　isGroupExpanded(int groupPosition) :判断此组是否展开　　2.代码：ExpandableListContextMenuInfo menuInfo=(ExpandableListContextMenuInfo)item.getMenuInfo();String title=((TextView)menuInfo.targetView).getText().toString();int type=ExpandableListView.getPackedPositionType(menuInfo.packedPosition);if (type==ExpandableListView.PACKED_POSITION_TYPE_CHILD) {int groupPos =ExpandableListView.getPackedPositionGroup(menuInfo.packedPosition);int childPos =ExpandableListView.getPackedPositionChild(menuInfo.packedPosition);二、ExpandableListAdapter　　　　一个接口，将基础数据链接到一个ExpandableListView。此接口的实施将提供访问Child的数据（由组分类），并实例化的Child和Group。 getChildId(int groupPosition, int childPosition) 获取与在给定组给予孩子相关的数据。 　　　　getChildrenCount(int groupPosition) 返回在指定Group的Child数目。

Rules::The AsyncTask instance must be created in UI thread. .execute must be invoked on the UI thread.Never call  objMyTask.onPreExecute(), objMyTask.doInBackground(), objMyTask.onProgressUpdate(),  objMyTask.onPostExecute manually.The AsyncTask can be executed only once (an exception will be thrown if a second execution is attempted.)AsyncTask have Four Main Method... onPreExecute()  doInBackground() onProgressUpdate() onPostExecute()  onPreExecute-This method is called first when you start AsyncTask using objAsync.execute().And mostly this method is use for initializing dialog(ProgressDialog,CustomDialog) and showing. doInBackground-The main purpose of AsyncTask is accomplished by this method.Any non-UI thread process is running in this method.Such as Rss Feed Reader,Image and video Uploading and Downloading.You cant handle your View in this method.Because this method is non-UI thread.While any background process is running if you want to handle UI therea are  onProgressUpdate method. after completion of process this method send result to OnPostExecute. onProgressUpdate-While backgrounding task is running ,you can handle your UI using this method .Such as status of downloading or uploading task.and this method is called from  doInBackground.Using publishProgress() you can call onProgressUpdate method to update UI while process is running. onPostExecute -This method is called after the background computation finishes.The result of background process in passed in this method as parameters.And now you can dismiss progress dialog ,to indicate that background task is completed. You can cancel AsyncTask using objAsyncTask.cancel().then you just check in doInBackground, if (isCancelled()) { break; } else {        //continue... } See this Image For more Clear.

Activity生命周期实例

可收缩界面控件

android 滑动删除例子源码下载

安装之后就能不断的唤醒，实现后台service持续运行，并且唤醒之后进入自定义界面