Java 在两个活动之间传递双精度-意图无法正常工作

我正在开发一个应用程序，它将根据用户的卡路里需求随机生成一个菜单。对于我的第一项活动，我要求用户提供输入，并收集计算每日卡路里需求所需的信息。卡路里需求是我需要转移到第二项活动中的双倍值，以便准确生成菜单。我一直在寻找我能找到的任何来源，但我没有找到任何可行的解决办法。正如您将看到的，我尝试使用getIntent（），并尝试在第二个活动中使用方法调用，但运行后该值不会更新，即使卡路里计算正确，该方法始终返回0.0。我觉得这可能是一个简单的解决办法，但我无法理解我做错了什么

代码如下：

活动1:

package com.jfreitas2.freitas_project1;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    Intent good = new Intent(MainActivity.this, Main2Activity.class);
    public double weight1, calNeeds;
    RadioButton mrad, frad;
    EditText weight, age;
    CheckBox kg, lb, sed, mod, act;
    String gender;
    int age1;
    TextView test;
    double cals = 0;



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

        //find all Id's related to the check boxes and radio buttons
        mrad =  (RadioButton) findViewById(R.id.malerad);
        frad =  (RadioButton) findViewById(R.id.femalerad);
        lb =    (CheckBox) findViewById(R.id.lbCheck);
        kg =    (CheckBox) findViewById(R.id.kgCheck);
        sed =   (CheckBox) findViewById(R.id.checkSed);
        mod =   (CheckBox) findViewById(R.id.checkMod);
        act =   (CheckBox) findViewById(R.id.checkAct);

        addListenerToCheckBoxes(); //adds listeners to all check boxes and radio buttons
        checkBoxOnlyOne(); //ensures only one checkbox/radio button can be checked within each pair
        addListenerOnButton(); //runs program to determine ideal body weight


    }
    public void addListenerOnButton()//runs program to determine ideal body weight
    {
        //finds calculate button's ID
        Button btn = (Button) findViewById(R.id.etbutton);

        //run everything below this when button is clicked (calculate ideal body weight)
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                calNeeds = getUserCalNeeds();
                good.putExtra("cals", calNeeds);
                startActivity(good);

            }
        });
    }
    public void addListenerToCheckBoxes()//adds listeners to all check boxes and radio buttons to set them checked when clicked
    {
        lb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                lb.setChecked(true);//set to checked
            }
        });
        kg.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                kg.setChecked(true);//set to checked
            }
        });
        mrad.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mrad.setChecked(true);//set to checked
            }
        });
        frad.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                frad.setChecked(true);//set to checked
            }
        });
        sed.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                sed.setChecked(true);//set to checked
            }
        });
        mod.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mod.setChecked(true);
            }
        });
        act.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                act.setChecked(true);
            }
        });
    }
    public void checkBoxOnlyOne()//ensures only one checkbox/radio button can be checked within each pair
    {
        lb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                kg.setChecked(false);//change accompanying button to false
            }
        });
        kg.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                lb.setChecked(false);//change accompanying button to false
            }
        });
        mrad.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                frad.setChecked(false);//change accompanying button to false
            }
        });
        frad.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                mrad.setChecked(false);//change accompanying button to false
            }
        });
        sed.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                mod.setChecked(false);
                act.setChecked(false);
            }
        });
        mod.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                sed.setChecked(false);
                act.setChecked(false);
            }
        });
        act.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                sed.setChecked(false);
                mod.setChecked(false);
            }
        });
    }
    public double getUserCalNeeds()
    {
        //retrieve ID's
        weight =(EditText) findViewById(R.id.editWeight);
        age =   (EditText) findViewById(R.id.editAge);

        //turn Strings into doubles in order to run equations
        weight1 = Double.parseDouble(weight.getText().toString());
        age1 = Integer.parseInt(age.getText().toString());

        //check what gender was chosen for choosing an equation
        if(mrad.isChecked())
            gender = "male";
        else if(frad.isChecked())
            gender = "female";

        //check if weight is kg or lb.. if it is lbs then we convert to kg
        if(lb.isChecked())
            weight1 = weight1*0.45359237;

        if(gender == "female") {
            if (age1 >= 3 && age1 <= 9) calNeeds = (22.5 * weight1) + 499;
            else if (age1 >= 10 && age1 <= 17) calNeeds = (12.2 * weight1) + 746;
            else if (age1 >= 18 && age1 <= 29) calNeeds = (10.7 * weight1) + 496;
            else if (age1 >= 30 && age1 <= 60) calNeeds = (8.7 * weight1) + 829;
            else if (age1 >= 61) calNeeds = (10.5 * weight1) + 596;
        }
        else if(gender == "male") {
            if (age1 >= 3 && age1 <= 9) calNeeds = (22.7 * weight1) + 495;
            else if (age1 >= 10 && age1 <= 17) calNeeds = (17.5 * weight1) + 651;
            else if (age1 >= 18 && age1 <= 29) calNeeds = (15.3 * weight1) + 679;
            else if (age1 >= 30 && age1 <= 60) calNeeds = (11.6 * weight1) + 879;
            else if (age1 >= 61) calNeeds = (13.5 * weight1) + 487;
        }

        if(sed.isChecked())
            calNeeds *= 1.2;
        else if(mod.isChecked())
            calNeeds *= 1.3;
        else if(act.isChecked())
            calNeeds *= 1.4;

        return calNeeds;
    }
    public double getCals()
    {
        return calNeeds;
    }
}

package com.jfreitas2.freitas_project1；
导入android.content.Intent；
导入android.support.v7.app.AppActivity；
导入android.os.Bundle；
导入android.view.view；
导入android.widget.Button；
导入android.widget.CheckBox；
导入android.widget.CompoundButton；
导入android.widget.EditText；
导入android.widget.RadioButton；
导入android.widget.RadioGroup；
导入android.widget.TextView；
公共类MainActivity扩展了AppCompatActivity{
意向良好=新意向（MainActivity.this、Main2Activity.class）；
公共双权重1，calNeeds；
无线按钮mrad，frad；
编辑文本重量、年龄；
复选框kg、lb、sed、mod、act；
字符串性别；
国际年龄1；
文本视图测试；
双CAL=0；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
//查找与复选框和单选按钮相关的所有Id
mrad=（单选按钮）findViewById（R.id.malerad）；
frad=（单选按钮）findViewById（R.id.femalerad）；
lb=（复选框）findViewById（R.id.lbCheck）；
kg=（复选框）findViewById（R.id.kgCheck）；
sed=（复选框）findviewbyd（R.id.checkSed）；
mod=（复选框）findviewbyd（R.id.checkMod）；
act=（复选框）findViewById（R.id.checkAct）；
AddListenerToCheckBox（）；//将侦听器添加到所有复选框和单选按钮
checkBoxOnlyOne（）；//确保每对中只能选中一个复选框/单选按钮
addListenerOnButton（）；//运行程序以确定理想体重
}
public void addListenerOnButton（）//运行程序以确定理想体重
{
//查找计算按钮的ID
按钮btn=（按钮）findViewById（R.id.etbutton）；
//单击按钮时，运行此按钮下方的所有内容（计算理想体重）
btn.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
calNeeds=getUserCalNeeds（）；
好的。putExtra（“cals”，calNeeds）；
星形触觉（良好）；
}
});
}
public void addListenerToCheckBox（）//将侦听器添加到所有复选框和单选按钮中，以便在单击时将其设置为选中
{
lb.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
lb.setChecked（true）；//设置为checked
}
});
kg.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
kg.setChecked（true）；//设置为checked
}
});
mrad.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
mrad.setChecked（true）；//设置为checked
}
});
frad.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
frad.setChecked（true）；//设置为checked
}
});
sed.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
sed.setChecked（true）；//设置为checked
}
});
mod.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
mod.setChecked（真）；
}
});
act.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
act.setChecked（正确）；
}
});
}
public void checkBoxOnlyOne（）//确保每对中只能选中一个复选框/单选按钮
{
lb.setOnCheckedChangeListener（新建CompoundButton.OnCheckedChangeListener（）{
@凌驾
检查更改后的公共无效（复合按钮视图，布尔值已检查）{
kg.setChecked（false）；//将伴随按钮更改为false
}
});
setOnCheckedChangeListener（新的CompoundButton.OnCheckedChangeListener（）{
@凌驾
检查更改后的公共无效（复合按钮视图，布尔值已检查）{
lb.setChecked（false）；//将伴随按钮更改为false
}
});
setOnCheckedChangeListener（新的CompoundButton.OnCheckedChangeListener（）{
@凌驾
检查更改后的公共无效（复合按钮视图，布尔值已检查）{
frad.setChecked（false）；//将伴随按钮更改为false
}
});
frad.setOnCheckedChangeListener（新的CompoundButton.OnCheckedChangeListener（）{
@凌驾
检查更改后的公共无效（复合按钮视图，布尔值已检查）{
mrad.setChecked（false）；//将伴随按钮更改为false
}
});
setOnCheckedChangeListener（新建CompoundButton.OnCheckedChangeLi
package com.jfreitas2.freitas_project1;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;

public class Main2Activity extends AppCompatActivity {

    //MainActivity main = new MainActivity();
    double calNeeds = getIntent().getDoubleExtra("cals", 0.0);
    public HashMap<String, Integer> breakie = new HashMap<String, Integer>(), lunchie = new HashMap<String, Integer>(), dindin = new HashMap<String, Integer>(); //create hashmaps for food and calories
    public ArrayList<String> breakArr = new ArrayList<String>(), lunchArr = new ArrayList<String>(), dinArr = new ArrayList<String>(); //arrays to fill with food to compare to hashmaps.
    public ArrayList<String> bMenu = new ArrayList<String>(), lMenu = new ArrayList<String>(), dMenu = new ArrayList<String>();
    public ListView bList, lList, dList;
    TextView totalCal;
    int count = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        bList = (ListView) findViewById(R.id.breakList);
        lList = (ListView) findViewById(R.id.lunchList);
        dList = (ListView) findViewById(R.id.dinnerList);
        totalCal = (TextView) findViewById(R.id.totalCal);

        //fillMaps();
        //fillArrayLists();
        //fillMenus();

        //totalCal.setText(""+calNeeds);


    }
    public void fillMaps()
    {
        //Fill Breakfast Map
        breakie.put("2 Eggs", 156);
        breakie.put("3 Strips Bacon", 129);
        breakie.put("2 Sausage Links", 340);
        breakie.put("1 Cup Cereal", 307);
        breakie.put("1 Large Banana", 121);
        breakie.put("2 Slices Wheat Bread with Peanut Butter", 326);
        breakie.put("1 Cup Strawberries", 50);
        breakie.put("2 Pieces French Toast", 300);
        breakie.put("2 Medium Pancakes with Syrup", 232);
        breakie.put("1 Chewie Granola Bar", 100);
        //
        //Fill Lunch Map
        lunchie.put("1 Chicken Breast", 231);
        lunchie.put("4 Slices Turkey Breast", 88);
        lunchie.put("2 Slices Wheat Bread", 138);
        lunchie.put("5 Piece Chicken Tenders", 230);
        lunchie.put("1 Small Caesar Salad", 94);
        lunchie.put("1 Chicken Salad Sandwich", 200);
        lunchie.put("1 Small Bag of Chips", 153);
        lunchie.put("1 Quesadilla", 528);
        lunchie.put("1 Cup Chicken Alfredo", 415);
        lunchie.put("1 Ham Sandwich", 292);
        //
        //Fill Dinner Map
        dindin.put("1 5oz Steak", 429);
        dindin.put("6oz Spinach", 40);
        dindin.put("6oz Cooked Pasta", 225);
        dindin.put("4oz French Fries", 365);
        dindin.put("1 Hamburger", 254);
        dindin.put("1 Slice Pizza", 185);
        dindin.put("1 Garden Salad", 100);
        dindin.put("1 Chicken Parm Dish", 400);
        dindin.put("3 Chicken Wings", 300);
        dindin.put("1 Potato Roasted", 161);

        //
    }
    public void fillArrayLists()
    {
        //filling arraylist with food for breakfast
        breakArr.add("2 Eggs"); breakArr.add("3 Strips Bacon"); breakArr.add("2 Sausage Links");
        breakArr.add("2 Cups Cereal"); breakArr.add("1 Large Banana"); breakArr.add("2 Slices Wheat Toast with Peanut Butter");
        breakArr.add("1 Cup Strawberries"); breakArr.add("2 Pieces French Toast"); breakArr.add("2 Medium Pancakes with Syrup");
        breakArr.add("1 Chewie Granola Bar");
        //
        //filling arraylist with food for lunch
        lunchArr.add("1 Chicken Breast"); lunchArr.add("4 Slices Turkey Breast"); lunchArr.add("2 Slices Wheat Bread");
        lunchArr.add("5 Piece Chicken Tenders"); lunchArr.add("1 Small Caesar Salad"); lunchArr.add("1 Chicken Salad Sandwich");
        lunchArr.add("1 Small Bag of Chips"); lunchArr.add("1 Quesadilla"); lunchArr.add("1 Cup Chicken Alfredo");
        lunchArr.add("1 Ham Sandwich");
        //
        //filling arraylist with food for dinner
        dinArr.add("1 5oz Steak"); dinArr.add("6oz Spinach"); dinArr.add("6oz Cooked Pasta");
        dinArr.add("4oz French Fries"); dinArr.add("1 Hamburger"); dinArr.add("1 Slice Pizza");
        dinArr.add("1 Garden Salad"); dinArr.add("1 Chicken Parm Dish"); dinArr.add("3 Chicken Wings");
        dinArr.add("1 Potato Roasted");
    }
    public void fillMenus()
    {
        Random rand = new Random(10);
        int x;
        double currentCal = 0;

        while(currentCal < calNeeds)
        {
            //add to breakfast menu
            x = rand.nextInt();
            currentCal += breakie.get(breakArr.get(x));
            bMenu.add(breakArr.get(x));

            //add to lunch menu
            x = rand.nextInt();
            currentCal += lunchie.get(lunchArr.get(x));
            lMenu.add(lunchArr.get(x));

            //add to dinner menu
            x = rand.nextInt();
            currentCal += dindin.get(dinArr.get(x));
            dMenu.add(dinArr.get(x));
            count++;
        }
    }
    /*public void displayMenus()
    {
        bList = (ListView) findViewById(R.id.breakList);
        lList = (ListView) findViewById(R.id.lunchList);
        dList = (ListView) findViewById(R.id.dinnerList);
        test = (TextView) findViewById(R.id.textView);

        test.setText(bMenu.get(0));

        ArrayAdapter<String> breakAdapter = new ArrayAdapter<String>(Main2Activity.this, android.R.layout.simple_list_item_1, bMenu);
        bList.setAdapter(breakAdapter);

    }*/
}

if (gender.equals("female")) {
(...)
} else if (gender.equals("male")) {
(...)
}