【Android】Fragment 呼叫 Fragment

Bundle arguments = new Bundle();

int menuIndex = 1;

arguments.putInt("expand_menu_type", menuIndex);

BFragment fragment = new BFragment();

fragment.setArguments(arguments);

getFragmentManager().beginTransaction().replace(R.id.expand_menu, fragment, BFragment.class.getName()).addToBackStack(BFragment.class.getName()).commitAllowingStateLoss();

//點擊widget id R.id.expand_menu

//欲前往Fragment BFragment

//Class Name為BFragment.class.getName()

//

【Android】implements OnItemClickListener 的class 取得activity

class xxx extends Fragment implements OnItemClickListener

【情境1】切換activity

Intent intent = new Intent(this, ooo.class);←false

Intent intent = new Intent(getActivity(), ooo.class);←true

【情境2】show dialog

↓false

new AlertDialog.Builder(this).setTitle("")

      .setMessage(R.string.nonetworkalert)

      .setCancelable(false)

      .setPositiveButton(R.string.sure,

         new DialogInterface.OnClickListener()

         {

             public void onClick(DialogInterface dialoginterface, int i)

             { 

             }

         }

      ).show();

↓true

new AlertDialog.Builder(getActivity()).setTitle("")

      .setMessage(R.string.nonetworkalert)

      .setCancelable(false)

      .setPositiveButton(R.string.sure,

         new DialogInterface.OnClickListener()

         {

             public void onClick(DialogInterface dialoginterface, int i)

             { 

             }

         }

      ).show();

【Android】onKeyDown = 返回上一頁

@Override

public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {

     backButton(findViewById(R.id.imageButton1));

        return false;

    }

    return false;

}

        public void backButton(View v)

{

  Intent intent = new Intent();

  intent.setClass(this, xxx.class);

  Bundle bundle = new Bundle();

  bundle.putString("maptype",maptype);

  intent.putExtras(bundle);

  startActivity(intent);

  finish();

}

【Android】Bundle/Intent 返回正確的上一頁

＜方法一＞

＜page 1＞

Intent intent = new Intent(this, xxx.class);

intent.putExtra("back_class", this.getClass().getName());

startActivity(intent);

======================================================================================

＜page2＞

String clazz = getIntent().getStringExtra("back_class");

＜方法二＞

＜page 1＞

Intent intent = new Intent();

Bundle bundle = new Bundle();

bundle.putString("header_title", getString(R.string.transaction));

bundle.putInt("header_background_color", getResources().getColor(R.color.main_func));

bundle.putString("header_back_to", "Submenu_pageA");

intentMenuItem.setClass(Submenu_pageA.this,Submenu_pageB.class);

intentMenuItem.putExtras(bundle);

startActivity(intentMenuItem);

======================================================================================

＜page 2＞

Bundle bundle = null;

public void onCreate(Bundle savedInstanceState) {

     super.onCreate(savedInstanceState);

bundle = this.getIntent().getExtras();

if(bundle.containsKey("header_back_to") && bundle.getString("header_back_to").equals("Submenu_pageA")){

  setReturnClass(Submenu_pageA.class);

}else{

  setReturnClass(HomeActivity.class);

}

}

【Android】若API回傳沒此欄位也不會exception

//若回傳沒此欄位也不會exception

JSONArray ary = (result.has("po_rec_cur")) ? result.getJSONArray("po_rec_cur") : null;

int length = (ary != null) ? ary.length() : 0;

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

    JSONObject obj = ary.getJSONObject(i);

    SomeClass item = new SomeClass();

    //若回傳沒此欄位也不會exception

    item.buy_time = obj.has("buy_time") ? obj.getString("buy_time") : "";

}