私が知る限り、私が使用するすべての変数は、最初に値が与えられなければ使用されません。nullpointerexception は、このアクティビティが開始された瞬間に発生します。具体的には言えません。
package pd.wilson.com;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
public class Page3 extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.page3);
final RadioGroup size = (RadioGroup)findViewById(R.id.RGSize);
final RadioGroup crust = (RadioGroup)findViewById(R.id.RGCrust);
final RadioButton small = (RadioButton)findViewById(R.id.RBS);
final RadioButton medium = (RadioButton)findViewById(R.id.RBM);
final RadioButton large = (RadioButton)findViewById(R.id.RBL);
final RadioButton regular = (RadioButton)findViewById(R.id.RBRegular);
final RadioButton thin = (RadioButton)findViewById(R.id.RBThin);
final String sizeS, crustS;
if (size.getCheckedRadioButtonId() == small.getId()){
sizeS = "Small";
}
else if(size.getCheckedRadioButtonId() == medium.getId()){
sizeS = "Medium";
}
else{
sizeS = "Large";
}
if (crust.getCheckedRadioButtonId() == regular.getId()){
crustS = "Regular";
}
else{
crustS = "Thin";
}
TextView size1 = (TextView)findViewById(R.id.tvsize);
size1.setText(sizeS);
TextView crust1 = (TextView)findViewById(R.id.tvcrust);
crust1.setText(crustS);
final CheckBox sausage = (CheckBox)findViewById(R.id.cbsausage);
int i1 = Ifchecked.gettrue(sausage);
final CheckBox mushrooms = (CheckBox)findViewById(R.id.cbmushrooms);
int i2 = Ifchecked.gettrue(mushrooms);
final CheckBox pepperoni = (CheckBox)findViewById(R.id.cbpepperoni);
int i3 = Ifchecked.gettrue(pepperoni);
final CheckBox onions = (CheckBox)findViewById(R.id.cbonions);
int i4 = Ifchecked.gettrue(onions);
final CheckBox ham = (CheckBox)findViewById(R.id.cbham);
int i5 = Ifchecked.gettrue(ham);
final CheckBox peppers = (CheckBox)findViewById(R.id.cbpeppers);
int i6 = Ifchecked.gettrue(peppers);
final CheckBox beef = (CheckBox)findViewById(R.id.cbbeef);
int i7 = Ifchecked.gettrue(beef);
final CheckBox tomatoes = (CheckBox)findViewById(R.id.cbtomatoes);
int i8 = Ifchecked.gettrue(tomatoes);
final CheckBox bacon = (CheckBox)findViewById(R.id.cbbacon);
int i9 = Ifchecked.gettrue(bacon);
final CheckBox green = (CheckBox)findViewById(R.id.cbgreen);
int i10 = Ifchecked.gettrue(green);
final CheckBox olives = (CheckBox)findViewById(R.id.cbolives);
int i11 = Ifchecked.gettrue(olives);
int numtop = i1+i2+i3+i4+i5+i6+i7+i8+i9+i10+i11;
}
}
スタックトレース：
04-04 01:41:46.536: D/AndroidRuntime(676): Shutting down VM
04-04 01:41:46.536: W/dalvikvm(676): threadid=1: thread exiting with uncaught exception (group=0x40015560)
04-04 01:41:46.556: E/AndroidRuntime(676): FATAL EXCEPTION: main
04-04 01:41:46.556: E/AndroidRuntime(676): java.lang.RuntimeException: Unable to start activity ComponentInfo{pd.wilson.com/pd.wilson.com.Page3}: java.lang.NullPointerException
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.os.Looper.loop(Looper.java:123)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.ActivityThread.main(ActivityThread.java:3683)
04-04 01:41:46.556: E/AndroidRuntime(676): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 01:41:46.556: E/AndroidRuntime(676): at java.lang.reflect.Method.invoke(Method.java:507)
04-04 01:41:46.556: E/AndroidRuntime(676): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-04 01:41:46.556: E/AndroidRuntime(676): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-04 01:41:46.556: E/AndroidRuntime(676): at dalvik.system.NativeStart.main(Native Method)
04-04 01:41:46.556: E/AndroidRuntime(676): Caused by: java.lang.NullPointerException
04-04 01:41:46.556: E/AndroidRuntime(676): at pd.wilson.com.Page3.onCreate(Page3.java:29)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-04 01:41:46.556: E/AndroidRuntime(676): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
04-04 01:41:46.556: E/AndroidRuntime(676): ... 11 more
04-04 01:41:48.256: I/Process(676): Sending signal. PID: 676 SIG: 9
04-04 01:45:18.077: D/AndroidRuntime(733): Shutting down VM
04-04 01:45:18.077: W/dalvikvm(733): threadid=1: thread exiting with uncaught exception (group=0x40015560)
04-04 01:45:18.099: E/AndroidRuntime(733): FATAL EXCEPTION: main
04-04 01:45:18.099: E/AndroidRuntime(733): java.lang.RuntimeException: Unable to start activity ComponentInfo{pd.wilson.com/pd.wilson.com.Page3}: java.lang.NullPointerException
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.os.Looper.loop(Looper.java:123)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.ActivityThread.main(ActivityThread.java:3683)
04-04 01:45:18.099: E/AndroidRuntime(733): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 01:45:18.099: E/AndroidRuntime(733): at java.lang.reflect.Method.invoke(Method.java:507)
04-04 01:45:18.099: E/AndroidRuntime(733): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-04 01:45:18.099: E/AndroidRuntime(733): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-04 01:45:18.099: E/AndroidRuntime(733): at dalvik.system.NativeStart.main(Native Method)
04-04 01:45:18.099: E/AndroidRuntime(733): Caused by: java.lang.NullPointerException
04-04 01:45:18.099: E/AndroidRuntime(733): at pd.wilson.com.Page3.onCreate(Page3.java:29)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-04 01:45:18.099: E/AndroidRuntime(733): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
04-04 01:45:18.099: E/AndroidRuntime(733): ... 11 more
04-04 01:46:10.457: D/AndroidRuntime(767): Shutting down VM
04-04 01:46:10.457: W/dalvikvm(767): threadid=1: thread exiting with uncaught exception (group=0x40015560)
04-04 01:46:10.496: E/AndroidRuntime(767): FATAL EXCEPTION: main
04-04 01:46:10.496: E/AndroidRuntime(767): java.lang.RuntimeException: Unable to start activity ComponentInfo{pd.wilson.com/pd.wilson.com.Page3}: java.lang.NullPointerException
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.os.Looper.loop(Looper.java:123)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.ActivityThread.main(ActivityThread.java:3683)
04-04 01:46:10.496: E/AndroidRuntime(767): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 01:46:10.496: E/AndroidRuntime(767): at java.lang.reflect.Method.invoke(Method.java:507)
04-04 01:46:10.496: E/AndroidRuntime(767): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-04 01:46:10.496: E/AndroidRuntime(767): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-04 01:46:10.496: E/AndroidRuntime(767): at dalvik.system.NativeStart.main(Native Method)
04-04 01:46:10.496: E/AndroidRuntime(767): Caused by: java.lang.NullPointerException
04-04 01:46:10.496: E/AndroidRuntime(767): at pd.wilson.com.Page3.onCreate(Page3.java:29)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-04 01:46:10.496: E/AndroidRuntime(767): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
04-04 01:46:10.496: E/AndroidRuntime(767): ... 11 more
04-04 01:46:12.348: I/Process(767): Sending signal. PID: 767 SIG: 9
04-04 01:55:31.597: D/AndroidRuntime(800): Shutting down VM
04-04 01:55:31.597: W/dalvikvm(800): threadid=1: thread exiting with uncaught exception (group=0x40015560)
04-04 01:55:31.607: E/AndroidRuntime(800): FATAL EXCEPTION: main
04-04 01:55:31.607: E/AndroidRuntime(800): java.lang.RuntimeException: Unable to start activity ComponentInfo{pd.wilson.com/pd.wilson.com.Page3}: java.lang.NullPointerException
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.os.Looper.loop(Looper.java:123)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.ActivityThread.main(ActivityThread.java:3683)
04-04 01:55:31.607: E/AndroidRuntime(800): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 01:55:31.607: E/AndroidRuntime(800): at java.lang.reflect.Method.invoke(Method.java:507)
04-04 01:55:31.607: E/AndroidRuntime(800): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-04 01:55:31.607: E/AndroidRuntime(800): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-04 01:55:31.607: E/AndroidRuntime(800): at dalvik.system.NativeStart.main(Native Method)
04-04 01:55:31.607: E/AndroidRuntime(800): Caused by: java.lang.NullPointerException
04-04 01:55:31.607: E/AndroidRuntime(800): at pd.wilson.com.Page3.onCreate(Page3.java:29)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-04 01:55:31.607: E/AndroidRuntime(800): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
04-04 01:55:31.607: E/AndroidRuntime(800): ... 11 more
04-04 01:55:33.357: I/Process(800): Sending signal. PID: 800 SIG: 9