XML CODE <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"; xmlns:tools="http://schemas.android.com/tools"; android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.android.mycalculator.MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/Operation" android:textSize="20sp"/> <Spinner android:id="@+id/spinner" android:layout_width="fill_parent" android:layout_height="wrap_content" android:prompt="@string/spinner_title" android:layout_marginTop="25dp" /> <EditText android:id="@+id/number1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:hint="Enter Number" android:inputType="number" android:layout_below="@+id/spinner"/> <EditText android:id="@+id/number2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:hint="Enter Number" android:inputType="number" android:layout_below="@+id/number1"/> <TextView android:id="@+id/result" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:paddingLeft="8dp" android:paddingRight="8dp" android:text="RESULT" android:textColor="#000000" android:textSize="20sp" android:layout_below="@id/number2"/> <View android:layout_width="150dp" android:layout_height="2dp" android:layout_below="@+id/result" android:background="@android:color/darker_gray" /> </RelativeLayout> //Java Code package com.example.android.mycalculator; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.EditText; import android.widget.Spinner; import android.widget.TextView; public class MainActivity extends Activity implements AdapterView.OnItemSelectedListener { Spinner spinner; TextView result; private EditText text1; private EditText text2; double l1,l2; private String[] operations = {"Add","Subtract","Multiply","Divide"}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); spinner = (Spinner) findViewById(R.id.spinner); result=(TextView) findViewById(R.id.result); spinner.setOnItemSelectedListener(this); text1 = (EditText) findViewById(R.id.number1); text2 = (EditText) findViewById(R.id.number2); l1 = Double.parseDouble(text1.getText().toString()); l2=Double.parseDouble(text2.getText().toString()); // Spinner Drop down elements // Creating adapter for spinner ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, operations); // Drop down layout style - list view with radio button dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); // attaching data adapter to spinner spinner.setAdapter(dataAdapter); } public String add() { double result=l1+l2; return Double.toString(result); } public String sub() { double result=l1-l2; return Double.toString(result); } public String mul() { double result=l1*l2; return Double.toString(result); } public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { // On selecting a spinner item String item = parent.getItemAtPosition(position).toString(); String selected = (String) spinner.getSelectedItem(); if(selected.equals(operations[0])) result.setText(add()); if(selected.equals(operations[1])) result.setText(sub()); if(selected.equals(operations[2])) result.setText(mul()); } public void onNothingSelected(AdapterView<?> arg0) { // TODO Auto-generated method stub } } I am not able to compile my app.It is getting crashed when i run it on my device.It is showing the error -Invalid double: "".I am not able to figure out the error.PLease Help me. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/android-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/android-developers/8e101adf-60a2-42e5-90cf-9194b0ce0700%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
