public class MainActivity extends AppCompatActivity { private ListView listView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); listView = (ListView) findViewById(R.id.mylist); findViewById(R.id.mybtn).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { ConnectivityManager manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE); NetworkInfo info = manager.getActiveNetworkInfo(); if (info != null && info.isAvailable()) {//网络可用 MyTask task = new MyTask(); try { String path = "http://apis.juhe.cn/cook/query.php"; String value = "menu=" + URLEncoder.encode("土豆", "utf-8") + "&key=13af589c334ec80c037688e927407966&rn=1"; //开启异步任务，传入一个string数组，第一个是网络地址，第二个是参数； task.execute(new String[]{path, value}); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } else { //弹出提醒网络未开启，跳转开启网络界面 showDialog(); } } }); } //重写异步任务 class MyTask extends AsyncTask<String, Integer, DataBean> { @Override protected DataBean doInBackground(String... params) { //网络请求 String json = getNetData(params[0], params[1]); DataBean bean = new Gson().fromJson(json, DataBean.class); return bean; } @Override protected void onPostExecute(DataBean dataBean) { super.onPostExecute(dataBean); //UI操作,给listview赋值，显示第一个菜单里的步骤 MyAdapter adapter = new MyAdapter(MainActivity.this, dataBean.result.data.get(0).steps); listView.setAdapter(adapter); } } //post网络请求 private String getNetData(String path, String value) { //获取URL的对象 try { URL url = new URL(path); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("POST"); connection.setDoOutput(true); //写入参数 OutputStream outputStream = connection.getOutputStream(); outputStream.write(value.getBytes()); //获取网络请求状态码 int code = connection.getResponseCode(); //200，连接成功 System.out.println(code+" code"); if (code == HttpURLConnection.HTTP_OK) { //获取网络请求返回的输入流 InputStream is = connection.getInputStream(); BufferedReader reader = new BufferedReader(new InputStreamReader(is)); String str = ""; StringBuilder builder = new StringBuilder(); while ((str = reader.readLine()) != null) { builder.append(str); } return builder.toString(); } } catch (Exception e) { e.printStackTrace(); } return null; } //显示网络提醒对话框 private void showDialog() { AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this); builder.setTitle("网络状态提醒"); builder.setMessage("您的网络未开启，是否开启网络？"); builder.setPositiveButton("开启网络", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { //开启网络界面,使用隐示意图 //根据版本号做不同操作 if (Build.VERSION.SDK_INT > 10) { Intent intent = new Intent(Settings.ACTION_WIRELESS_SETTINGS); startActivity(intent); } else { //SDK<10 Intent intent = new Intent(); ComponentName name = new ComponentName("com.android.settings", "com.android.settings.WIRELESS_SETTINGS"); // Settings.ACTION_WIRELESS_SETTINGS; intent.setComponent(name); intent.setAction(Intent.ACTION_VIEW); startActivity(intent); } dialog.dismiss(); } }); builder.setNegativeButton("不开启", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); builder.create().show(); } }
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