Question

我知道这可能很简单，但我的应用程序无效。我需要在Edittext中输入权重并使用其值，方法CalculateDistance的总距离值和CalculateCalories方法的值。使用此代码，我无法点击Start按钮。我在哪里必须添加从Edittext获取值的代码以及如何使其工作？

我的代码目前看起来像这样：

public class RunningModeFragment extends Fragment implements IGPSActivity
{

    MyLocation myLocation=null;
    Button btnRunningModeStart=null;
    EditText txtWeight=null;
    TextView txtTotalDistance=null;
    TextView txtCalories=null;
    Button btnShowRunningHistory = null;

    String weight;
    Float weightInKg;
    Float caloriesBurned;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        return inflater.inflate(R.layout.running_mode_fragment, container, false);
    }

    public void onViewCreated(View view, Bundle savedInstanceState)
    {
        super.onViewCreated(view, savedInstanceState);

        txtTotalDistance=(TextView) getView().findViewById(R.id.txtTotalDistance);
        txtWeight=(EditText) getView().findViewById(R.id.txtWeight);
        txtCalories=(TextView) getView().findViewById(R.id.txtCalories);
        if (txtWeight.getText().toString().isEmpty())
        {
            return;
        }
        else {
            weight = txtWeight.getText().toString();
            weightInKg = Float.parseFloat(weight);
        }

        btnRunningModeStart = (Button) getView().findViewById(R.id.btnRunningModeStart);
        btnRunningModeStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v)
            {
                onClick_StartRunningMode(v);
            }
        });

        btnShowRunningHistory = (Button) getView().findViewById(R.id.btnShowRunningHistory);
        btnShowRunningHistory.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                onClick_ShowRunningHistory(v);
            }
        });

    }

    private void onClick_ShowRunningHistory(View v) {

        Fragment fragment = new RunningHistoryFragment();
        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
        FragmentTransaction transaction = getFragmentManager().beginTransaction();
        transaction.replace(R.id.fragment_container, fragment, "Running History");
        transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        transaction.commit();
    }


    private void onClick_StartRunningMode(View v)

    {
        if(myLocation ==null)
        {
            new Thread(new Runnable() {
                public void run() {

                    DatabaseFacade dbfacade = new DatabaseFacade(getView().getContext());
                    Activity activity = new Activity(ActivityMode.RUNNING);
                    activity.setActivityId(activity.getActivityId());
                    activity.setStart(new Timestamp(new Date().getTime()));
                    dbfacade.saveActivity(activity);

                }
            }).start();


            Toast.makeText(this.getActivity(), "Start Running mode", Toast.LENGTH_SHORT).show();
            myLocation = new MyLocation();
            myLocation.LocationStart(this);
            btnRunningModeStart.setText("Stop");
        }

        else
        {
            Toast.makeText(this.getActivity(), "Stop Running mode", Toast.LENGTH_SHORT).show();
            myLocation.LocationListenerStop();
            myLocation = null;
            btnRunningModeStart.setText("Start");
        }
    }


    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data);
    }


    Location lastPoint = null;
    float totalDistance = 0;

    public static float CalculateDistance(Location startPoint, Location endPoint)
    {
        return (startPoint.distanceTo(endPoint) / ((float)1000));
    }

    public static float CalculateCalories(float a, float b){
        return ((float)1.036)*a*b;
    }



    @Override
    public void locationChanged(Location location)
    {
        try
        {

            if(lastPoint==null)lastPoint = location;

            totalDistance += CalculateDistance(lastPoint, location);

            lastPoint=location;
            txtTotalDistance.setText(totalDistance + " km");
            caloriesBurned=CalculateCalories(totalDistance,weightInKg);
            txtCalories.setText(caloriesBurned + " kcal");

            DatabaseFacade dbf = new DatabaseFacade(getView().getContext());
            Activity activity = new Activity(ActivityMode.RUNNING);
            dbf.saveLocation(new GpsLocation(activity.getActivityId(), location.getLongitude(), location.getLatitude(), location.getAccuracy()));
        }catch (Exception E)

        {
            E.printStackTrace();
        }
    }


    public void onResume(){
        super.onResume();
        ((Main) getActivity()).setActionBarTitle("Running mode");
        NavigationView navigationView = (NavigationView) getActivity().findViewById(R.id.nav_view);
        //  navigationView.setNavigationItemSelectedListener((Main) getActivity());
        navigationView.setCheckedItem(R.id.runningMode);

    }
}

我需要做以下事情：从EditText txtWeight获取值，将其解析为float并在CalculateCalories方法中使用

  public static float CalculateCalories(float a, float b){
        return ((float)1.036)*a*b;
    }

我试过这个，但它没有用

  if (txtWeight.getText().toString().isEmpty())
    {
        return;
    }
    else {
        weight = txtWeight.getText().toString();
        weightInKg = Float.parseFloat(weight);
    }

Answer 1

首先创建一个视图而不是在onCreateView中初始化textview，就像这样，

View view = inflater.inflate(R.layout.fg_unapproved_leave, container, false);
Textview tv= view.findViewById(R.id.tv);

你在onViewCreated（）中编写的代码应该在onCreateVIew（）中。从onViewCreated（）中删除它。

Answer 2

你可以把它放在onCreateView()上@jitendra purohit告诉你，如下：

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        View view = inflater.inflate(R.layout.fg_unapproved_leave, container, false);
        txtTotalDistance=(TextView) view.findViewById(R.id.txtTotalDistance);
        txtWeight=(EditText) view.findViewById(R.id.txtWeight);
        txtCalories=(TextView) view.findViewById(R.id.txtCalories);
        ...
        return view;
    }

或者您可以将代码保存在onViewCreated()中，而不是getView()，您可以执行getActivity()这样的代码：

public void onViewCreated(View view, Bundle savedInstanceState)
    {
        super.onViewCreated(view, savedInstanceState);
        txtTotalDistance=(TextView) getActivity().findViewById(R.id.txtTotalDistance);
        txtWeight=(EditText) getActivity().findViewById(R.id.txtWeight);
        txtCalories=(TextView) getActivity().findViewById(R.id.txtCalories);
        ...

请参阅此question/answers以及......

您可以在onClick()中执行此操作，或者如果您希望动态显示更改，请使用TextWatcher。

使用TextWatchers

TextWatcher textWatcher = new TextWatcher（）{

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @Override
    public void afterTextChanged(Editable s) {
        if (txtWeight.getText().toString().isEmpty()) {
            return;
        }
        else {
            weight = txtWeight.getText().toString();
            weightInKg = Float.parseFloat(weight);
            //Call your CalculateCalories method
        }
    }
};

}

使用onClick我不会实现它，但您可以使用Button或同一EditText来执行此操作，并执行与afterChangedText()相同的操作{1}}上的{1}}。

请记住TextWatcher，你必须这样做：

onCreateView()

Answer 3

放那行==＆gt; weight = txtWeight.getText（）。toString（）;在onCLick方法

btnShowRunningHistory = (Button) getView().findViewById(R.id.btnShowRunningHistory);
    btnShowRunningHistory.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if (txtWeight.getText().toString().isEmpty())
              {
                  return;
              }
         else {
                  weight = txtWeight.getText().toString();
                  weightInKg = Float.parseFloat(weight);
              }
            onClick_ShowRunningHistory(v);
        }
    });

不能在android片段中使用来自edittext的值，在哪里放置它？

3 个答案: