当我点击保存按钮时没有输入任何内容时应用程序崩溃。 应该弹出错误

Question

Im developing a calorie app. The problem I'm having right now is if the user decided to press save without entering anything the app should notify the user they must input something in order to save calorie. The app works when the user does input the proper values of the edit text.

Problem : App crashes when user clicks save button when they havent inputted anything.

logcat.

                                                         05-01 12:46:50.294 1810-1810/com.example.treycoco.calorietracker E/AndroidRuntime: FATAL EXCEPTION: main
                                                                               Process: com.example.treycoco.calorietracker, PID: 1810
                                                                               java.lang.NumberFormatException: Invalid int: ""
                                                                                   at java.lang.Integer.invalidInt(Integer.java:137)
                                                                                   at java.lang.Integer.parseInt(Integer.java:358)
                                                                                   at java.lang.Integer.parseInt(Integer.java:331)
                                                                                   at com.example.treycoco.calorietracker.AddEntry.saveDataToDB(AddEntry.java:100)
                                                                                   at com.example.treycoco.calorietracker.AddEntry$1.onClick(AddEntry.java:79)
                                                                                   at android.view.View.performClick(View.java:4438)
                                                                                   at android.view.View$PerformClick.run(View.java:18422)
                                                                                   at android.os.Handler.handleCallback(Handler.java:733)
                                                                                   at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                   at android.os.Looper.loop(Looper.java:136)
                                                                                   at android.app.ActivityThread.main(ActivityThread.java:5045)
                                                                                   at java.lang.reflect.Method.invokeNative(Native Method)
                                                                                   at java.lang.reflect.Method.invoke(Method.java:515)
                                                                                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
                                                                                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
                                                                                   at dalvik.system.NativeStart.main(Native Method)

AddEntry.java

                   public class AddEntry extends Fragment implements  
                   View.OnClickListener  {

                   EditText DescriptionET,CalorieET;
                   ImageButton Savebtn, Cancelbtn;

                   String description , calorieAmt;

                   //database
                   private DatabaseHandler dba;



                     public AddEntry() {
                   // Required empty public constructor
                   }


                     @Override
                   public View onCreateView(LayoutInflater inflater, 
                   ViewGroup container,
                         Bundle savedInstanceState) {

                     // Inflate the layout for this fragment
                   View myView = 
                  inflater.inflate(R.layout.fragment_add_entry, 
                container, false);
                 Savebtn = (ImageButton) myView.findViewById(R.id.SaveBtn);
               Savebtn.setBackgroundColor(Color.TRANSPARENT);
                Savebtn.setOnClickListener(this);


             Cancelbtn = (ImageButton) myView.findViewById(R.id.CancelBtn);
             Cancelbtn.setBackgroundColor(Color.TRANSPARENT);
                Cancelbtn.setOnClickListener(this);
                return myView;
                   }


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

             DescriptionET= (EditText)view.findViewById(R.id.foodEditText);

             DescriptionET.setInputType(InputType.TYPE_CLASS_TEXT);

            CalorieET=(EditText)view.findViewById(R.id.caloriesEditText);
            CalorieET.setInputType(InputType.TYPE_CLASS_NUMBER);


           //save to database:
           dba = new DatabaseHandler(getContext());


           Savebtn.setOnClickListener(new View.OnClickListener() {
             @Override
           public void onClick(View arg0) {

              saveDataToDB();


             }
         });


         }





           public void saveDataToDB (){

           Food food = new Food();
           String name = DescriptionET.getText().toString().trim();
            String calString = CalorieET.getText().toString().trim();

            //convert the claories numbers to text

           int cal = Integer.parseInt(calString);


           if (DescriptionET.getText().toString().equals("") || 
           CalorieET.getText().toString().equals("0")){

           Toast.makeText(getActivity(), "Please enter information", 
              Toast.LENGTH_LONG).show();
          }else{

        food.setFoodName(name);
        food.setCalories(cal);

        //call addFood method from the DatabaseHandler
        dba.addFood(food);
        dba.close();


        //clear the editTexts
        DescriptionET.setText("");
        CalorieET.setText("");

        //take the user to the next screen
        //


        ((appMain) getActivity()).loadSelection(0);;
    }

}


             @Override
            public void onClick(View v) {
             switch (v.getId()) {


                case R.id.SaveBtn:


            description = DescriptionET.getText().toString();
            calorieAmt=CalorieET.getText().toString();

            if (DescriptionET.getText().toString().equals("") ||
            CalorieET.getText().toString().equals("0")){

           Toast.makeText(getActivity(), "Please enter information", 
            Toast.LENGTH_LONG).show();
            }



            break;


                   case R.id.CancelBtn:

                    EditText descriptionET=  
              (EditText)getView().findViewById(R.id.foodEditText);
                 descriptionET.setText("");


            EditText calorieET= 
          (EditText)getView().findViewById(R.id.caloriesEditText);
            calorieET.setText("");

            break;
    }
}

}

Answer 1

Just add a NULL check for the calories value.

if(CalorieET.getText().toString().equals("")
{
Toast.makeText(this,"Please Enter a Value", 3000)show();
}
else
{
//code here to add it to db
}

Answer 2

change your line

if (DescriptionET.getText().toString().equals("") || 
       cal==0){

       Toast.makeText(getActivity(), "Please enter information", 
          Toast.LENGTH_LONG).show();
      }

Answer 3

if (TextUtils.isEmpty(DescriptionET.getText().toString()) || TextUtils.isEmpty(CalorieET.getText().toString())
 {
 Toast.makeText(getActivity(), "Please enter information", 
      Toast.LENGTH_LONG).show();
 }

Answer 4

Actually you set onClickListener of your Savebtn to something else than the function you try to check the sanity of the input, so you need to move your condition checking before you call saveDataToDB .

Change this part of your code:

 Savebtn.setOnClickListener(new View.OnClickListener() {
         @Override
       public void onClick(View arg0) {
           if (DescriptionET.getText().toString().equals("") || 
               CalorieET.getText().toString().equals("0") ||
               CalorieET.getText().toString().equals("")){

                Toast.makeText(getActivity(), "Please enter information", 
                Toast.LENGTH_LONG).show();
            }
           else {
               saveDataToDB();
           }


         }
     });

Answer 5

          if (!calString.equals("")) {

        int cal = Integer.parseInt(calString);


            //code for database
        ;