小编Jef*_*eff的帖子

我是android开发新手,并做了一个简单的计算器项目.但是,我的应用程序不断崩溃,我不明白为什么.请帮忙

Java代码:

package com.example.zhiwen.calculator;
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;

public class MainActivity extends AppCompatActivity {

Button plus,minus,times,divide;
TextView textview3;
EditText first, second;
double no1 = 0, no2 = 0;
double answer = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    plus = (Button) findViewById(R.id.plus);
    minus = (Button) findViewById(R.id.minus);
    times = (Button) findViewById(R.id.times);
    divide = (Button) findViewById(R.id.divide);
    textview3 = (TextView) findViewById(R.id.textview3);
    first = (EditText) findViewById(R.id.editText);
    second = (EditText) findViewById(R.id.editText2);
}

public void ClickMeButton(View …