Im a beginner in java but I'm trying to build exercises and I ran into this problem. The user types in a donation, presses the button and the value of donations increments. Ive written the entire code but when I click the button to add to the donation count, the app crashes. Ive followed all the teachings of my teacher. I create a method in the activity, the in the ui builder I go to the button on click property and set it to that method. It should go smoothly but it crashes whenever I click the button. This is my activity which I set the onClick property to computeDonation.
public void computeDonation(View v){
String addedText = ((EditText)findViewById(R.id.AmountText)).getText().toString();
DonationModel donation = new DonationModel(addedText);
String answer = donation.calcDonation();
((TextView)findViewById(R.id.totalText)).setText(answer);
}
This is the model:
String textAdded;
double addedDonation;
public DonationModel(String y) {
textAdded = y;
}
public String calcDonation(){
double counter = Double.parseDouble(textAdded);
addedDonation += counter;
Locale locale = new Locale("en", "CA");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
return fmt.format(addedDonation);
}
Ive even tried without the number format just to see if it sends back to the activity but it doesn't. BTW for my class I'm using an older version of android studio.
This is the logcat:
02-15 17:12:28.797 21619-21619/ca.roumani.donations E/AndroidRuntime: FATAL EXCEPTION: main Process: ca.roumani.donations, PID: 21619 java.lang.IllegalStateException: Could not execute method for android:onClick at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293) at android.view.View.performClick(View.java:5197) at android.view.View$PerformClick.run(View.java:20909) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:145) at android.app.ActivityThread.main(ActivityThread.java:5942) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) at android.view.View.performClick(View.java:5197) at android.view.View$PerformClick.run(View.java:20909) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:145) at android.app.ActivityThread.main(ActivityThread.java:5942) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) Caused by: java.lang.NumberFormatException: Invalid double: "" at java.lang.StringToReal.invalidReal(StringToReal.java:63) at java.lang.StringToReal.parseDouble(StringToReal.java:267) at java.lang.Double.parseDouble(Double.java:301) at ca.roumani.donations.DonationModel.calcDonation(DonationModel.java:20) at ca.roumani.donations.DonationActivity.computeDonation(DonationActivity.java:24) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) at android.view.View.performClick(View.java:5197) at android.view.View$PerformClick.run(View.java:20909) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:145) at android.app.ActivityThread.main(ActivityThread.java:5942) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)