E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.chayoungyun2, PID: 12817
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.chayoungyun2/com.example.chayoungyun2.calculatorActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2724)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2789)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1527)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:203)
at android.app.ActivityThread.main(ActivityThread.java:6251)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1063)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:924)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.example.chayoungyun2.calculatorActivity.onCreate(calculatorActivity.java:46)
at android.app.Activity.performCreate(Activity.java:6666)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2677)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2789)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1527)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:203)
at android.app.ActivityThread.main(ActivityThread.java:6251)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1063)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:924)
package com.example.chayoungyun2;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class calculatorActivity extends AppCompatActivity {
EditText et_show,et_result;
Button add,sub,mul,div,remainder,del;
Button result;
String history = "";
String number1 = "";
String number2 = "";
int type;
int ADD = 0;
int SUB = 1;
int MUL = 2;
int DIV = 3;
int REMAINDER = 4;
double d1;
double d2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_show = findViewById(R.id.et_show);
et_result = findViewById(R.id.et_result);
et_result.setText("");
add = findViewById(R.id.btn_add);
sub = findViewById(R.id.btn_sub);
mul = findViewById(R.id.btn_mul);
div = findViewById(R.id.btn_div);
remainder = findViewById(R.id.btn_remainder);
del = findViewById(R.id.btn_del);
result = findViewById(R.id.btn_result);
add.setOnClickListener(mListener);
sub.setOnClickListener(mListener);
mul.setOnClickListener(mListener);
div.setOnClickListener(mListener);
remainder.setOnClickListener(mListener);
result.setOnClickListener(mListener);
del.setOnClickListener(mListener);
Button clear = findViewById(R.id.btn_clear);
clear.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
et_show.setText("");
et_result.setText("");
d1 = d2 = 0;
history = number1 = number2 = "";
}
});
Button plus_minus = findViewById(R.id.btn_plus_minus);
plus_minus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//실수인지 정수인지 판단해서 부호 바꾸기
if( ( (Double.parseDouble(et_result.getText().toString())) - ((int)Double.parseDouble(et_result.getText().toString())) ) == 0.0 )
{
et_result.setText( "" + (Integer.parseInt(et_result.getText().toString()) * -1) );
}
else {
et_result.setText( "" + (Double.parseDouble(et_result.getText().toString()) * -1) );
}
}
});
}
다른곳에서 쓰던거 activity중 하나에다가 넣어줬는데 실행시 오류가뜨네요 ...ㅜㅜ
더웃긴건 됬었는데 갑자기 안된다는 겁니다...
Main 에서 버튼으로 현재 엑티비티버튼 클릭시 앱실행중지 오류가 뜹니다...