IllegalStateException with onclick function

1
votes

I have created a OnbuttonClick function and implement it on two button Calculator and reset. While clicking on reset its reset the values but while clicking on calculate its make a illegalstatexception. I have go through the question on this forum but not able to find the solution

package com.example.rajafarid.hc;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;


public class FoodStorage extends MainActivity {
public int sum = 1;
public int  result;
public int wheatlb = 25;
public int wheatkg = 10;

public int beanlb = 5;
public int beankg = 2;

EditText editTextNOP;
EditText editTextNOMS;
EditText editTextWheat;
EditText editTextBeans;
Button   btnCalculate;
Button   btnReset;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_food_storage);
    editTextNOP = (EditText) findViewById(R.id.editTextNOP);
    editTextNOMS = (EditText) findViewById(R.id.editTextNOMS);
    btnCalculate = (Button) findViewById(R.id.btnCalculate);
    btnReset = (Button) findViewById(R.id.btnReset);
}

here is the function OnButtonClick

public void OnButtonClick(View v)
{

    if (v.getId() == R.id.btnCalculate)
    {
        result = sum*wheatlb;
        int result1 = sum*wheatkg;
        editTextWheat.setText(result+"lb or" +wheatkg+"kg");

        int bean = sum*beanlb;
        int bean1=sum*beankg;
        editTextBeans.setText(bean+"lb or"+beankg+"kg");
    }

    else if (v.getId()==R.id.btnReset)
    {
        editTextNOP.setText("");
        editTextNOMS.setText("");
    }
}
}

logcat file:

java.lang.IllegalStateException: Could not execute method of the activity at android.view.View$1.onClick(View.java:4222) at android.view.View.performClick(View.java:5156) at android.view.View$PerformClick.run(View.java:20755) 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:5832) at 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.view.View$1.onClick(View.java:4217) at android.view.View.performClick(View.java:5156)  at android.view.View$PerformClick.run(View.java:20755)  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:5832)  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.NullPointerException: Attempt to invoke virtual method 'void android.widget.EditText.setText(java.lang.CharSequence)' on a null object reference at com.example.rajafarid.hc.FoodStorage.OnButtonClick(FoodStorage.java:42) at java.lang.reflect.Method.invoke(Native Method)  at java.lang.reflect.Method.invoke(Method.java:372)  at android.view.View$1.onClick(View.java:4217)  at android.view.View.performClick(View.java:5156)  at android.view.View$PerformClick.run(View.java:20755)  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:5832)  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)

3
android
editTextWheat =null it's clear – M D

3 Answers

1
votes

App crashes because of NullPointerException. the problem is you are not initialising editTextWheat and editTextBeans. you are trying to call setText method on a null reference. so as you did for other two TextViews initialize these TextViews in your onCreate();

@Override
protected void onCreate(Bundle b){
        editTextWheat = (EditText) findViewById(R.id.id_of_edit_text_wheat);
        editTextBeans = (EditText) findViewById(R.id.id_of_edit_text_beans);
        ........
    }

that will solve the problem

1
votes

Null for editTextWheat & editTextBeans because they are holding null when you use setText() with them

use findViewById() method to assign editTextWheat & editTextBeans

0
votes

You have to make findViewById for both editTextWheat,editTextBeans in onCreate view

editTextWheat = (EditText) findViewById(R.id.your editTextWheat view ID );
editTextBeans  = (EditText) findViewById(R.id.your editTextBeans view ID );