2. Drop-down refresh, two-dimensional code

Drop-down Refresh

• Pulltorefresh

  • Support Listview,webview,gridview,expandablelistview Many controls

    1,lv_list = refreshListView.getRefreshableView();//需要拿到refreshListView这个组合控件里面的具体的listview,才可以设置adapter2.refreshListView.setRefreshing();//开始加载数据的时候.应该显示.正在刷新3.refreshListView.onRefreshComplete();//结束刷新状态4.  refreshListView.setOnRefreshListener(new OnRefreshListener() {@Overridepublic void onRefresh() {    //下拉刷新中.我们应该去重写请求数据    initData();    System.out.println("===setOnRefreshListener====");}});

• Xlistview: Easy to modify layout

  • Only ListView supported

  • Key methods

    xlv.setPullLoadEnable(true);//开启上拉加载更多xlv.setPullRefreshEnable(true);//开启下拉刷新xlv.stopRefresh();//停止刷新xlv.stopLoadMore();//停止加载更多xlv.setXListViewListener(new IXListViewListener() {//设置监听@Overridepublic void onRefresh() {    handler.sendMessageDelayed(new Message(), 2000);}@Overridepublic void onLoadMore() {    for (int i = 0; i < 100; i++) {        String str = "这个是一个item条目 " + i;        dataSource.add(str);    }    handler.sendMessageDelayed(new Message(), 2000);}});xlv.setRefreshTime(preUpdateTime2);//设置上次更新时间

Encapsulation of the network engine

• The network request is encapsulated into the cloudengine.class and exposed in the form of a method;
• Processing of all network request results. Callback back by means of interface method;

Interface callbacks

• Handler mechanism +thread
• How to understand the interface callback--the interface callback is a notification mechanism
• Effect: 1. Simple notification 2. Notification + value
• Steps:
  • 1. Define interfaces, and interface methods
  • 2. Defining Interface Objects
  • 3. In a certain place. Interface Object Call interface method
  • 4. Exposing interface Objects (construction method, setter method)

Asynctask Basic Use

onPredoInbackGrouponpost

Asynctask Source Code Analysis

private static final int CORE_POOL_SIZE = 5;        //核心线程数private static final int MAXIMUM_POOL_SIZE = 128;   //最大线程数private static final int KEEP_ALIVE = 1;            

Asynctask defects

• 1. At the same time there are only 5 threads to access the network--this is the point
• 2. The number of threads is more than 128, will throw an exception--this situation is actually OK;

Asynctask Version Differences

• COREPOOLsize maximum_poolsize KEEPalive on different versions. The value is not the same;
• 1.5 was executed serially. One task at a time
• Previous versions of 1.6-2.3. is executed in parallel. Perform 5 tasks at a time

• Serial and parallel are provided after 3.0, and the default is serial

  executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, null);//串行executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, null);//并行

Asynctask Simple Package

Actual development we will inherit asynctask.

Asynctask functional encapsulation, Asynctask function invocation interface Callback instance

    //1.    public static interface OnCheckedChangeListener {    void onCheckedChanged(CompoundButton buttonView, boolean isChecked);   }    //2.    private OnCheckedChangeListener mOnCheckedChangeListener;    //3.    mOnCheckedChangeListener.onCheckedChanged(this, mChecked);    //4.     public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {    mOnCheckedChangeListener = listener;    }

Global exception Handling

• Method defines the place. Uniform throw base class

  /** *  这个是一个会抛出异常b的方法 * @throws HMException * @throws HMException */public static void methodB() throws HMException {    //如果在某一个时刻.出现了异常啊.    //出现状态的是子类.抛出的是父类.    throw new HMBException();//主动抛异常}

• Where the method is used, the try catch base class

  try {            Api.methodB();        } catch (HMException e) {            handleException(e);}

• Hint Information materialized

  /** * 不同异常子类用不同的code表示 * @param e * @return */public static int exception2code(HMException e) {int errCode = 0;if (e instanceof HMAException) {    errCode = 1;} else if (e instanceof HMBException) {    errCode = 2;} else if (e instanceof HMCException) {    errCode = 3;} else if (e instanceof HMDException) {    errCode = 4;}return errCode;}/** * 根据不同的异常信息.显示不同的效果 * @param e */public void handleException(HMException e) {    int exception2code = ExceptionHandler.exception2code(e);    String code2String = ExceptionHandler.code2String(exception2code);    Toast.makeText(getApplicationContext(), code2String, 0).show();}

Actionbarsherlock

Actionbar version Compatibility Library. We can use the Actionbar under 2.1.

    actionBar = getSupportActionBar();//得到actionbar,    actionBar.setDisplayHomeAsUpEnabled(true);//是否显示返回箭头,默认情况是false,    //如果setDisplayShowHomeEnabled setDisplayShowTitleEnabled 都是false,那么退回图标设置为true/false都不见    actionBar.setDisplayShowHomeEnabled(false);//是否显示logo,默认是true    actionBar.setDisplayShowTitleEnabled(true);//是否显示title,默认是true    //      actionBar.setTitle("56期");//修改title    //      actionBar.setIcon(R.drawable.icon_download);//修改logo

The difference between several actionbar

• Actionbarsherlock->actionbar--> support-->2.1 The following systems also have to be used, Actionbarsherlock provides a lot of styles;
• The system above v7-->actionbar-->2.1 can support
• Android sdk->actionbar-->3.0 above phone support

V4 V7 V13

• V4: Compatible with API Level4 (Android 1.6)
• V7: Compatible with API Level7 (Android 2.1)
• V13: Compatible with API Level3 (Android 3.2)

QR code, historic stuff.

Using the zxing package, QRCode

The simplification of two-dimensional code

It was a long time ago. The simplification of the zxing package is a comparison of fire.

Two-dimensional code and screen switching

The picture is cut sideways

Two-dimensional code animation

Imitation Scan effect

Using zxing to scan two-dimensional code to understand two-dimensional code

• The range of the QR code
• Two-dimensional code fault tolerance level
• Two-dimensional Code embedded logo

Use the Find button first and then call

1. Start the scanning interface Intent Intent = new Intent (mainactivity.this, Captureactivity.class); Startactivityforresult (Intent, scannin_grequest_code);//2. Processing Scan Results/** * * @param result * @param barcode */public void Han    Dledecode (result result, Bitmap barcode) {inactivitytimer.onactivity ();    Playbeepsoundandvibrate ();    Scan result String resultstring = Result.gettext ();    if (Resultstring.equals (")") {Toast.maketext (Captureactivity.this, "Scan failed!", Toast.length_short). Show ();        } else {//2. Pass the scan result Intent resultintent = new Intent ();        Bundle bundle = new bundle ();        Bundle.putstring ("result", resultstring);        Bundle.putparcelable ("Bitmap", barcode);        Resultintent.putextras (bundle);    This.setresult (RESULT_OK, resultintent); } CaptureActivity.this.finish ();} 3. Results of receiving callbacks @overrideprotected void Onactivityresult (int requestcode, int resultcode, Intent data) {Super.onactivityre  Sult (Requestcode, ResultCode, data);  Switch (requestcode) {case Scannin_grequest_code:if (ResultCode = = RESULT_OK) {Bundle bundle = d            Ata.getextras ();            Displays the contents of the scan Tv_result.settext (bundle.getstring ("result"));        Show Iv_qrcode.setimagebitmap ((Bitmap) Data.getparcelableextra ("Bitmap"));    } break; }}

Friends Leaguemulti-channel packaging can be UF tools, ant, Gradle

2. Drop-down refresh, two-dimensional code