Question

respected all;

I am new to programming and find a barrier i.e on clicking the button without any thing being inputted in the Edittext box converts mine activity to crash.

So after research i got Try and catch methods and it works good .

     public void clickDiv(View button){
     try{
         EditText Input = (EditText) findViewById(R.id.editext);

        String input = Input.getText().toString();

         String empty = "";

         Float floatInput = new Float (input);

         TextView TextShow = (TextView) findViewById(R.id.textView1);

         String Newinput = floatInput.toString();

         TextShow.setText(Newinput);

         if (answer == 0){

             answer =  (answer+1) / floatInput  ;
         }else{
             answer =  (answer) / floatInput  ;
         }
         String answerString = answer.toString();

         TextShow.setText(answerString);

         Input.setText(empty); }
         catch (Exception e) {
         AlertDialog alertDialog;
        alertDialog = new AlertDialog.Builder(this).create();
          alertDialog.setMessage("Could not find the operand");
         alertDialog.show();
      }}

But the main problem is that i have to use it in all the button methods.
is there any other way other to avoid this repetition in code.

Please help..

Answer 1

modify the code like this. Hope it helps you.

public void clickDiv(View button){
 try{
     EditText Input = (EditText) findViewById(R.id.editext);

    String input = Input.getText().toString();

     //if no input, set the error to the edittext and return
     if(input.trim().length()==0){
        Input.setError("An input is required");
        return;
     }
     String empty = "";

     Float floatInput = new Float (input);

     TextView TextShow = (TextView) findViewById(R.id.textView1);

     String Newinput = floatInput.toString();

     TextShow.setText(Newinput);

     if (answer == 0){

         answer =  (answer+1) / floatInput  ;
     }else{
         answer =  (answer) / floatInput  ;
     }
     String answerString = answer.toString();

     TextShow.setText(answerString);

     Input.setText(empty); }
     catch (Exception e) {
     AlertDialog alertDialog;
    alertDialog = new AlertDialog.Builder(this).create();
      alertDialog.setMessage("Could not find the operand");
     alertDialog.show();
  }}