Question

我试图使用参数将数据（PID）从片段扫描保存到片段维护

但我的Log.d中的数据始终为空（＆＃34;标记＆＃34;，＆＃34; PID扫描：＆＃34; +数据）;

我的论点有什么不对？

这是我的代码

public class FragmentScan extends Fragment {
    TextView tvPid;
    TextView txtName;
    TextView txtPrice;
    TextView txtDesc;
    TextView txtSpec;

    private ProgressDialog pDialog;


    JSONParser jsonParser = new JSONParser();

    private static final String url_product_detials = "http://10.0.3.2/skripsi/get_product_details.php";
    // JSON Node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_PRODUCT = "product";
    private static final String TAG_PID = "pid";
    private static final String TAG_NAME = "name";
    private static final String TAG_PRICE = "price";
    private static final String TAG_DESCRIPTION = "description";
    private static final String TAG_SPESIFICATION = "spesification";
    // Progress Dialog
    private static final String PID_KEY = "tvPid";
    private static final String NAME_KEY = "tvName";
    private static final String PRICE_KEY = "tvPrice";
    private static final String DESCRIPTION_KEY = "tvDesc";
    private static final String SPESIFICATION_KEY = "tvSpec";

    private String mPid=null;
    private String mName=null;
    private String mPrice=null;
    private String mDesc=null;
    private String mSpec=null;

    Button Btngetdata;
    ArrayList<HashMap<String, String>> oslist = new ArrayList<HashMap<String, String>>();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        Log.d("ZZZ", "ada di oncreateView");
        super.onCreate(savedInstanceState);
         View rootView = inflater.inflate(R.layout.fragment_layout_four, container, false);
        tvPid = (TextView) rootView.findViewById(R.id.tvPid);
        txtName = (TextView) rootView.findViewById(R.id.tvName);
        txtPrice = (TextView) rootView.findViewById(R.id.tvPrice);
        txtDesc = (TextView) rootView.findViewById(R.id.tvDesc);
        txtSpec = (TextView) rootView.findViewById(R.id.tvSpec);
        Btngetdata = (Button)rootView.findViewById(R.id.getdata);
        Btngetdata.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Fragment fragment = new FragmentMaintenance();
                Bundle data = new Bundle();
                data.putString("pid", mPid);
                fragment.setArguments(data);
                FragmentManager frgManager = getFragmentManager();
                Log.d("tag", "PID SCAN: " + data);
                frgManager.beginTransaction().replace(R.id.content_frame, fragment)
                        .commit();
            }
        });

        Button scanBtn = (Button) rootView.findViewById(R.id.btnScan);
        //in some trigger function e.g. button press within your code you should add:
        scanBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                try {
                    Intent intent = new Intent("com.google.zxing.client.android.SCAN");
                    intent.putExtra("SCAN_MODE", "QR_CODE_MODE,PRODUCT_MODE");
                    startActivityForResult(intent, 0);

                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    Toast.makeText(getActivity(), "ERROR:" + e, Toast.LENGTH_LONG).show();
                }
            }
        });
        if (savedInstanceState != null) {
            Log.d("ZZZ", "ada di di dlm if saved");

            mPid = savedInstanceState.getString(PID_KEY);
            mName = savedInstanceState.getString(NAME_KEY);
            mPrice = savedInstanceState.getString(PRICE_KEY);
            mDesc = savedInstanceState.getString(DESCRIPTION_KEY);
            mSpec = savedInstanceState.getString(SPESIFICATION_KEY);
            tvPid.setText(mPid);
            txtName.setText(mName);
            txtPrice.setText(mPrice);
            txtDesc.setText(mDesc);
            txtSpec.setText(mSpec);
        }
        return rootView;
    }


    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);
        Log.d("ZZZ", "Ada di mainactivity");
        if (requestCode == 0) {
            TextView pid = (TextView) getActivity().findViewById(R.id.tvPid);

            if (resultCode == Activity.RESULT_OK) {
                pid.setText(intent.getStringExtra("SCAN_RESULT"));
                new GetProductDetails(getActivity()).execute(pid.getText().toString());
            } else if (resultCode == Activity.RESULT_CANCELED) {
                pid.setText("Scan cancelled.");
            }
        }
    }


    class GetProductDetails extends AsyncTask<String, Void, String[]> {

        /**
         * Before starting background thread Show Progress Dialog
         */
        private Context mContext;

        public GetProductDetails(Context context) {
            mContext = context;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(mContext);
            pDialog.setMessage("Loading product details. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        /**
         * Getting product details in background thread
         */
        protected String[] doInBackground(String... string) {

            // Check for success tag
            int success;
            try {
                // Building Parameters
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("pid", string[0]));
                // getting product details by making HTTP request
                // Note that product details url will use GET request
                JSONObject json = jsonParser.makeHttpRequest(
                        url_product_detials, "GET", params);
                Log.d("ZZZ", json.toString());

                success = json.getInt(TAG_SUCCESS);
                if (success == 1) {
                    // successfully received product details
                    JSONArray productObj = json.getJSONArray(TAG_PRODUCT); // JSON Array

                    // get first product object from JSON Array
                    JSONObject product = productObj.getJSONObject(0);

                    // product with this pid found
                    // Edit Text
                    String[] result = {Integer.toString(success), product.getString(TAG_NAME), >                         product.getString(TAG_PRICE),
                    product.getString(TAG_DESCRIPTION),
                    product.getString(TAG_SPESIFICATION)};

//                    // display product data in EditText
//                    txtName.setText(product.getString(TAG_NAME));
//                    txtPrice.setText(product.getString(TAG_PRICE));
//                    txtDesc.setText(product.getString(TAG_DESCRIPTION));

                    Log.d("ZZZ", result[0]);
                    return result;
                } else {
                    Log.d("ZZZ", Integer.toString(success));
                    String[] result = {Integer.toString(success)};
                    return result;
                }
            } catch (JSONException e) {
                e.printStackTrace();
                return null;
            }
        }

        /**
         * After completing background task Dismiss the progress dialog
         * *
         */
        protected void onPostExecute(String[] results) {
            // dismiss the dialog once got all details
            pDialog.dismiss();

            if (results[0] != null) {
                Log.d("ZZZ", "SUCCESS" + results[0]);
                if (results[0].matches("1")) {
                    Log.d("ZZZ", "SUCCESS " + results[0]);
                    TextView name = (TextView) getActivity().findViewById(R.id.tvName);
                    name.setText(results[1]);
                    TextView price = (TextView) getActivity().findViewById(R.id.tvPrice);
                    price.setText(results[2]);
                    TextView desc = (TextView) getActivity().findViewById(R.id.tvDesc);
                    desc.setText(results[3]);
                    TextView spec = (TextView) getActivity().findViewById(R.id.tvSpec);
                    spec.setText(results[4]);
                } else if (results[0].matches("-1")) {
                    Toast.makeText(getActivity(), "No Internet Connection", Toast.LENGTH_SHORT).show();
                } else{
                    Log.d("ZZZ", "UNKNOWN ERROR");
                }
            }
        }
    }
    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
        // Save state information with a collection of key-value pairs
        // 4 lines of code, one for every count variable
        super.onSaveInstanceState(savedInstanceState);
        savedInstanceState.putString(PID_KEY, tvPid.getText().toString());
        savedInstanceState.putString(NAME_KEY, txtName.getText().toString());
        savedInstanceState.putString(PRICE_KEY, txtPrice.getText().toString());
        savedInstanceState.putString(DESCRIPTION_KEY, txtDesc.getText().toString());
        savedInstanceState.putString(SPESIFICATION_KEY, txtSpec.getText().toString());
    }
}

这是我的活动

公共类MainActivity扩展了Activity {

private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;

private CharSequence mDrawerTitle;
private CharSequence mTitle;
CustomDrawerAdapter adapter;
SharedPreferences preferences;
String pref;
List<DrawerItem> dataList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    preferences = this.getSharedPreferences(Config.PREFERENCES, MODE_PRIVATE);
    pref = preferences.getString(Config.SESSION,null);
    // Initializing
    dataList = new ArrayList<DrawerItem>();
    mTitle = mDrawerTitle = getTitle();
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerList = (ListView) findViewById(R.id.left_drawer);

    mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
            GravityCompat.START);

    // Add Drawer Item to dataList
    dataList.add(new DrawerItem("Scanner", R.drawable.ic_action_email));
    dataList.add(new DrawerItem("Schedule", R.drawable.ic_action_good));
    dataList.add(new DrawerItem("Games", R.drawable.ic_action_gamepad));
    dataList.add(new DrawerItem("Logout", R.drawable.ic_action_about));


    adapter = new CustomDrawerAdapter(this, R.layout.custom_drawer_item,
            dataList);

    mDrawerList.setAdapter(adapter);

    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

    getActionBar().setDisplayHomeAsUpEnabled(true);
    getActionBar().setHomeButtonEnabled(true);

    mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
            R.drawable.ic_drawer, R.string.drawer_open,
            R.string.drawer_close) {
        public void onDrawerClosed(View view) {
            getActionBar().setTitle(mTitle);
            invalidateOptionsMenu(); // creates call to
            // onPrepareOptionsMenu()
        }

        public void onDrawerOpened(View drawerView) {
            getActionBar().setTitle(mDrawerTitle);
            invalidateOptionsMenu(); // creates call to
            // onPrepareOptionsMenu()
        }
    };

    mDrawerLayout.setDrawerListener(mDrawerToggle);

    if (savedInstanceState == null) {
        SelectItem(0);
    }

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

public void SelectItem(int possition) {

    Fragment fragment = null;
    Bundle args = new Bundle();
    switch (possition) {
        case 0:
            fragment = new FragmentScan();
            break;
        case 1:
            fragment = new FragmentSchedule();

            break;
        case 2:
            fragment = new FragmentThree();
            args.putString(FragmentThree.ITEM_NAME, dataList.get(possition)
                    .getItemName());
            args.putInt(FragmentThree.IMAGE_RESOURCE_ID, dataList.get(possition)
                    .getImgResID());
            break;
        case 3:
            logout();
            Intent in = new Intent(this, LoginActivity.class);
            startActivity(in);
            finish();
            return;

        default:
            break;
    }

    fragment.setArguments(args);
    FragmentManager frgManager = getFragmentManager();
    frgManager.beginTransaction().replace(R.id.content_frame, fragment)
            .commit();

    mDrawerList.setItemChecked(possition, true);
    setTitle(dataList.get(possition).getItemName());
    mDrawerLayout.closeDrawer(mDrawerList);

}

@Override
public void setTitle(CharSequence title) {
    mTitle = title;
    getActionBar().setTitle(mTitle);
}

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    mDrawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    // Pass any configuration change to the drawer toggles
    mDrawerToggle.onConfigurationChanged(newConfig);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // The action bar home/up action should open or close the drawer.
    // ActionBarDrawerToggle will take care of this.
    if (mDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }

    return false;
}

private class DrawerItemClickListener implements
        ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
                            long id) {
        SelectItem(position);

    }
}
//In the same activity you’ll need the following to retrieve the results:
private void logout(){
    //TODO delete cookie from db

    SharedPreferences.Editor editor = preferences.edit();
    editor.remove(Config.SESSION);
    editor.remove(Config.USERNAME);
    editor.commit();
}

我希望有人可以帮我解决这个问题，谢谢。

Answer 1

我认为它应该不是空的，也许你只是没有正确地检索它。

在您的日志记录代码中，您使用了：

Log.d("tag", "PID SCAN: " + data);

但实际上您使用以下方式存储了pid：

data.putString("pid", mPid);

这意味着，您应该使用键pid从包中获取值，例如：

Log.d("tag", "PID SCAN: " + data.getString("pid"));

修改

如果它是您尝试获取的进程ID，请尝试查看android.os.Process.myPid();

如果pid是您自己的预定义变量（包含其他内容），然后你需要在创建片段时传递它，如下所示：

fragment = new FragmentScan(); args.putString("pid", YOUR_TV_PID_VALUE);

从另一方（FragmentScan），您可以使用getArguments()获取Bundle，然后使用getString("pid")。

<强>更新

在更多地阅读你的代码之后，似乎你的循环有点纠结。但有一个快速的建议是：为什么不尝试以下

data.putString("pid", tvPid.getText());

在原始代码中，点击pid后，savedInstanceState中的scanBtn应该存在，完成/取消扫描。但我认为你的代码流程有点纠结读取 here，onSaveInstanceState被调用以在被杀之前从活动中检索每个实例的状态。
=＆GT;这意味着，在打开另一个意图（由scanBtn执行）之前，会调用onSaveInstanceState并存储tvPid的空值。当主要意图恢复时，它会获得包含空字符串pid的包。但它应该是""，而不是空。

在片段之间保持数据

1 个答案: