title: Why do I get these errors on my logcat whenever I run my Android app in eclipse?
body: <p>I'm trying to test if my android app works, it consists of 2 activity screens. There are no errors in my codes but my app won't run. It always gives me this error on the emulator "Unfortunately 'application name' has stopped." </p>
  
  <p>Here is my Activity code</p>
  
  <pre><code>    public class MainActivity extends Activity
  {
  
          @Override
          public void onCreate(Bundle savedInstanceState)
          {
              super.onCreate(savedInstanceState);
              setContentView(R.layout.activity_main);
              View title = getWindow().findViewById(android.R.id.title);
              View titleBar = (View) title.getParent();
              titleBar.setBackgroundColor(Color.RED);
              Button next=(Button)findViewById(R.id.DGButton);
              next.setOnClickListener(new View.OnClickListener() {
                  public void onClick(View view) {
                      Intent myIntent=new Intent(view.getContext(), 
  
      Activity2.class);
                      startActivityForResult(myIntent, 0);
                  }});}
  
          public void calculateClickHandler(View view)
          {
              if (view.getId() == R.id.CalculateButton)
              {
                  EditText ageText = (EditText)findViewById
  
      (R.id.AgeField);
                  EditText weightText = (EditText)findViewById
  
      (R.id.WeightField);
                  EditText ftText = (EditText)findViewById
  
      (R.id.HeightField);
                  EditText inText = (EditText)findViewById
  
      (R.id.HeightField2);
                  RadioGroup weightRG = (RadioGroup) findViewById
  
      (R.id.WeightRG);
                  RadioGroup sexRG = (RadioGroup) findViewById
  
      (R.id.SexRG);
  
                  TextView resultText = (TextView)findViewById
  
      (R.id.ResultLabel);
                  TextView normalBMIText = (TextView)findViewById
  
      (R.id.NormalBMI);
                  TextView idealKgText = (TextView)findViewById
  
      (R.id.IdealKgLabel);
                  TextView idealLbText = (TextView)findViewById
  
      (R.id.IdealLbLabel);
                  int age = Integer.parseInt(ageText.getText
  
      ().toString());
                  double weight = Double.parseDouble
  
      (weightText.getText().toString());
                  double ftheight = Double.parseDouble(ftText.getText
  
      ().toString());
                  double inheight = Double.parseDouble(inText.getText
  
      ().toString());
                  int checkedRadioButton1 = 
  
      weightRG.getCheckedRadioButtonId();
                  int checkedRadioButton2 = 
  
      sexRG.getCheckedRadioButtonId();
  
                  double bmiValue = calculateBMI(weight, ftheight, 
  
      inheight, checkedRadioButton1);
                  String bmiInterpretation1 = interpretBMI1(bmiValue);
                  String bmiInterpretation2 = interpretBMI2(age);
                  String bmiInterpretation3 = interpretBMI3(ftheight, 
  
      inheight, checkedRadioButton2);
                  String bmiInterpretation4 = interpretBMI4(ftheight, 
  
      inheight, checkedRadioButton2);
  
                  resultText.setText(bmiValue + " - " + 
  
      bmiInterpretation1);
                  normalBMIText.setText(""+bmiInterpretation2);
                  idealKgText.setText(""+bmiInterpretation3);
                  idealLbText.setText(""+bmiInterpretation4);
  
                  Intent intent1 = new Intent(MainActivity.this, 
  
      Activity2.class);
                  Bundle b = new Bundle();
                  b.putDouble("key", bmiValue);
                  intent1.putExtras(b);
                  startActivity(intent1);
      }}
  </code></pre>
  
  <p><strong>This is the error logcat:</strong></p>
  
  <pre><code>12-26 02:50:45.606: E/AndroidRuntime(1776): FATAL EXCEPTION: main
  12-26 02:50:45.606: E/AndroidRuntime(1776): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bmicaldg/com.example.bmicaldg.MainActivity}: java.lang.NullPointerException
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.os.Handler.dispatchMessage(Handler.java:99)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.os.Looper.loop(Looper.java:137)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.ActivityThread.main(ActivityThread.java:5039)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at java.lang.reflect.Method.invokeNative(Native Method)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at java.lang.reflect.Method.invoke(Method.java:511)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at dalvik.system.NativeStart.main(Native Method)
  12-26 02:50:45.606: E/AndroidRuntime(1776): Caused by: java.lang.NullPointerException
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at com.example.bmicaldg.MainActivity.onCreate(MainActivity.java:25)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.Activity.performCreate(Activity.java:5104)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
  12-26 02:50:45.606: E/AndroidRuntime(1776):     ... 11 more
  </code></pre>
  
  <p><strong>This is the debug logcat:</strong></p>
  
  <pre><code> 12-26 03:04:06.238: I/Process(1854): Sending signal. PID: 1854 SIG: 9
      12-26 03:04:12.779: W/Trace(1876): Unexpected value from nativeGetEnabledTags: 0
      12-26 03:04:12.837: W/Trace(1876): Unexpected value from nativeGetEnabledTags: 0
      12-26 03:04:14.866: D/dalvikvm(1876): GC_CONCURRENT freed 76K, 7% free 2723K/2916K, paused 32ms+32ms, total 270ms
      12-26 03:04:15.427: D/AndroidRuntime(1876): Shutting down VM
      12-26 03:04:15.456: W/dalvikvm(1876): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
      12-26 03:04:15.546: E/AndroidRuntime(1876): FATAL EXCEPTION: main
      12-26 03:04:15.546: E/AndroidRuntime(1876): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bmicaldg/com.example.bmicaldg.MainActivity}: java.lang.NullPointerException
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.os.Handler.dispatchMessage(Handler.java:99)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.os.Looper.loop(Looper.java:137)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.ActivityThread.main(ActivityThread.java:5039)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at java.lang.reflect.Method.invokeNative(Native Method)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at java.lang.reflect.Method.invoke(Method.java:511)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at dalvik.system.NativeStart.main(Native Method)
      12-26 03:04:15.546: E/AndroidRuntime(1876): Caused by: java.lang.NullPointerException
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at com.example.bmicaldg.MainActivity.onCreate(MainActivity.java:25)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.Activity.performCreate(Activity.java:5104)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
      12-26 03:04:15.546: E/AndroidRuntime(1876):     ... 11 more
      12-26 03:04:22.547: I/Process(1876): Sending signal. PID: 1876 SIG: 9
  </code></pre>
  
  <p>Any help is appreciated</p>