//异步线程AsyncTask:开启线程下载，配合Json解析，还有适配器进度条、等控件使用(07)public class MainActivity extends Activity {private Spinner spinner;private ArrayAdapter<String> adapter;private ProgressBar pb;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);this.spinner = (Spinner) this.findViewById(R.id.spinner);String url = "http://litchiapi.jstv.com/api/GetFeeds?column=0&PageSize=20&pageIndex=1&val=100511D3BE5301280E0992C73A9DEC41";this.pb = (ProgressBar) this.findViewById(R.id.pb);new Mytask(this).execute(url);}class Mytask extends AsyncTask<String, Integer, byte[]> {private ProgressDialog dialog;public Mytask(Context context) {/** //这里不用对话提示了，采用进度条 dialog = new ProgressDialog(context);* dialog.setTitle("提示"); dialog.setMessage("正在下载数据！！");*/}@Overrideprotected void onPreExecute() {pb.setVisibility(View.VISIBLE);// 显示进度条/** dialog.show();//打开对话框 try { Thread.sleep(1000); } catch* (InterruptedException e) { e.printStackTrace(); }*/}@Overrideprotected void onProgressUpdate(Integer... values) {pb.setProgress(values[0]);}@Overrideprotected byte[] doInBackground(String... params) {// 下载JSON字符串String url = params[0];HttpClient client = new DefaultHttpClient();HttpGet get = new HttpGet(url);try {HttpResponse response = client.execute(get);if (response.getStatusLine().getStatusCode() == 200) {long totallenth = response.getEntity().getContentLength();BufferedInputStream br = new BufferedInputStream(response.getEntity().getContent());ByteArrayOutputStream bos = new ByteArrayOutputStream();int count = 0;// 进度条每次累加更新int len = -1;byte[] buf = new byte[100];while ((len = br.read(buf)) != -1) {bos.write(buf, 0, len);count += len;// 进度条计算int le = (int) ((count / (double) totallenth) * 100);publishProgress(le);// 进度条更新try {// Thread.currentThread().sleep(100);Thread.sleep(10);// 数据都太小太快，睡一下} catch (InterruptedException e) {e.printStackTrace();}}br.close();return bos.toByteArray();}} catch (ClientProtocolException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return null;}@Overrideprotected void onPostExecute(byte[] result) {if (result != null) {List<String> list = parser(new String(result));adapter = new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_list_item_1, list);spinner.setAdapter(adapter);//绑定数据和适配器} else {Toast.makeText(MainActivity.this, "网络连接错误！！",Toast.LENGTH_SHORT).show();}pb.setVisibility(View.GONE);// 隐藏进度条// dialog.dismiss();//关闭对话框}private List<String> parser(String json) {List<String> list = new ArrayList<String>();try {JSONObject obj = new JSONObject(json);JSONObject object_paramz = obj.getJSONObject("paramz");JSONArray array_feeds = object_paramz.getJSONArray("feeds");for (int i = 0; i < array_feeds.length(); i++) {JSONObject object = array_feeds.getJSONObject(i);JSONObject object_data = object.getJSONObject("data");list.add(object_data.getString("subject"));}} catch (JSONException e) {e.printStackTrace();}return list;}}
}//布局<ProgressBarandroid:id="@+id/pb"style="@android:style/Widget.ProgressBar.Horizontal"android:layout_width="match_parent"android:layout_height="wrap_content"android:visibility="gone" /><Spinnerandroid:id="@+id/spinner"android:layout_width="match_parent"android:layout_height="wrap_content" />