Java 添加EditText时片段中的NullPointerException

我正在使用一个选项卡式布局，使用向导创建，并准备好了一个片段。我已经在我的片段中添加了一些EditText，我已经准备好了，但是，当运行应用程序时，我在我的EditText声明中得到了一个NullPointerException

片段代码：

package com.boreas.snowdaycalculatorsp2;

import android.content.Context;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class AdvancedFragment extends Fragment {
    EditText inSnow, durnStorm, pSnow, pTime, fSnow, wSpeed, sGround;
    public double inchSnow, durationStorm, peakSnow, peakTime, finalSnow, windSpeed, snowGround, result;
    TextView results;
    Button calc;
    String resInt;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        inSnow = (EditText) getView().findViewById(R.id.inchesSnow);
        durnStorm = (EditText)getView().findViewById(R.id.durationStorm);
        pSnow = (EditText) getView().findViewById(R.id.peakRate);
        pTime = (EditText)getView().findViewById(R.id.peakRateTime);
        fSnow = (EditText) getView().findViewById(R.id.finalRate);
        wSpeed = (EditText) getView().findViewById(R.id.windSpeed);
        sGround = (EditText) getView().findViewById(R.id.snowGround);
        results = (TextView) getView().findViewById(R.id.resultView);
        calc = (Button) getView().findViewById(R.id.button);

        return inflater.inflate(R.layout.advfrag_layout, container, false);




    }

}

片段XML:

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:background="#000000"
    android:layout_height="match_parent">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/inchesSnow"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:hint="Inches of Snow"
        android:singleLine="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/durationStorm"
        android:layout_below="@+id/inchesSnow"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:hint="Duration of Storm"
        android:singleLine="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/peakRate"
        android:layout_below="@+id/durationStorm"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:hint="Peak Snow Rate"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:layout_alignParentStart="false"
        android:singleLine="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/peakRateTime"
        android:layout_below="@+id/peakRate"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:hint="Time of Peak Snow Rate"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:singleLine="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberSigned"
        android:ems="10"
        android:id="@+id/finalRate"
        android:layout_below="@+id/peakRateTime"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:hint="Final Snow Rate"
        android:singleLine="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberSigned"
        android:ems="10"
        android:id="@+id/windSpeed"
        android:layout_below="@+id/finalRate"
        android:layout_alignParentLeft="true"
        android:hint="Wind Speed"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:layout_alignParentRight="true"
        android:singleLine="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/snowGround"
        android:layout_below="@+id/windSpeed"
        android:layout_alignParentLeft="true"
        android:hint="Snow Already on Ground"
        android:textColor="#ffffff"
        android:textColorHint="#ffffff"
        android:layout_alignParentRight="true"
        android:singleLine="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Calculate"
        android:id="@+id/button"
        android:layout_below="@+id/snowGround"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="39dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:id="@+id/resultView"
        android:layout_below="@+id/button"
        android:layout_alignRight="@+id/button"
        android:layout_marginTop="41dp"
        android:layout_alignLeft="@+id/button" />

</RelativeLayout>

主要活动：

package com.boreas.snowdaycalculatorsp2;

import java.util.Locale;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity implements ActionBar.TabListener {

    SectionsPagerAdapter mSectionsPagerAdapter;
    ViewPager mViewPager;

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

        // Set up the action bar.
        final ActionBar actionBar = getSupportActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        // When swiping between different sections, select the corresponding
        // tab. We can also use ActionBar.Tab#select() to do this if we have
        // a reference to the Tab.
        mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                actionBar.setSelectedNavigationItem(position);
            }
        });

        // For each of the sections in the app, add a tab to the action bar.
        for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
            // Create a tab with text corresponding to the page title defined by
            // the adapter. Also specify this Activity object, which implements
            // the TabListener interface, as the callback (listener) for when
            // this tab is selected.
            actionBar.addTab(
                    actionBar.newTab()
                            .setText(mSectionsPagerAdapter.getPageTitle(i))
                            .setTabListener(this));
        }


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
        // When the given tab is selected, switch to the corresponding page in
        // the ViewPager.
        mViewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    }

    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a PlaceholderFragment (defined as a static inner class below).
            Fragment fragment;
            switch (position){
                case 0:
                    fragment = new BasicFragment();
                    break;
                case 1:
                    fragment = new AdvancedFragment();
                    break;
                default:
                    throw new IllegalArgumentException("Invalid Section Number");
            }




            return fragment;
        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            return 2;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
                case 0:
                    return "Basic";
                case 1:
                    return "Advanced";

            }
            return null;
        }
    }
}

package com.boreas.snowday计算器P2；
导入java.util.Locale；
导入android.support.v7.app.ActionBarActivity；
导入android.support.v7.app.ActionBar；
导入android.support.v4.app.Fragment；
导入android.support.v4.app.FragmentManager；
导入android.support.v4.app.FragmentTransaction；
导入android.support.v4.app.FragmentPagerAdapter；
导入android.os.Bundle；
导入android.support.v4.view.ViewPager；
导入android.view.Gravity；
导入android.view.LayoutInflater；
导入android.view.Menu；
导入android.view.MenuItem；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.TextView；
公共类MainActivity扩展ActionBarActivity实现ActionBar.TabListener{
分段SPAGERADAPTER mSectionsPagerAdapter；
ViewPager mViewPager；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
//设置操作栏。
最终ActionBar ActionBar=getSupportActionBar（）；
actionBar.setNavigationMode（actionBar.NAVIGATION\u MODE\u选项卡）；
//创建适配器，该适配器将为这三个函数中的每一个返回一个片段
//活动的主要部分。
mSectionsPagerAdapter=newsectionspageradapter（getSupportFragmentManager（））；
//使用分区适配器设置ViewPager。
mViewPager=（ViewPager）findViewById（R.id.pager）；
mViewPager.setAdapter（mSectionsPagerAdapter）；
//在不同区段之间滑动时，选择相应的
//我们也可以使用ActionBar.tab#select（）来完成这项工作
//对选项卡的引用。
mViewPager.setOnPageChangeListener（新的ViewPager.SimpleOnPageChangeListener（）{
@凌驾
已选择页面上的公共无效（内部位置）{
actionBar.setSelectedNavigationItem（位置）；
}
});
//对于应用程序中的每个部分，在操作栏中添加一个选项卡。
对于（int i=0；i

---

关于导致NullPointerException的原因有什么想法吗？

将

onCreateView

更改为

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.advfrag_layout, container, false); 
        // inflate the layout
        inSnow = (EditText) view.findViewById(R.id.inchesSnow);
        // use the inflated view object to initialize edittext 
        durnStorm = (EditText)view.findViewById(R.id.durationStorm);
        pSnow = (EditText) view.findViewById(R.id.peakRate);
        pTime = (EditText)view.findViewById(R.id.peakRateTime);
        fSnow = (EditText)view.findViewById(R.id.finalRate);
        wSpeed = (EditText) view.findViewById(R.id.windSpeed);
        sGround = (EditText) view.findViewById(R.id.snowGround);
        results = (TextView) view.findViewById(R.id.resultView);
        calc = (Button) view.findViewById(R.id.button);

        return view; // return view
      }

---

将创建视图上的

更改为

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.advfrag_layout, container, false); 
        // inflate the layout
        inSnow = (EditText) view.findViewById(R.id.inchesSnow);
        // use the inflated view object to initialize edittext 
        durnStorm = (EditText)view.findViewById(R.id.durationStorm);
        pSnow = (EditText) view.findViewById(R.id.peakRate);
        pTime = (EditText)view.findViewById(R.id.peakRateTime);
        fSnow = (EditText)view.findViewById(R.id.finalRate);
        wSpeed = (EditText) view.findViewById(R.id.windSpeed);
        sGround = (EditText) view.findViewById(R.id.snowGround);
        results = (TextView) view.findViewById(R.id.resultView);
        calc = (Button) view.findViewById(R.id.button);

        return view; // return view
      }

将创建视图上的
更改为

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.advfrag_layout, container, false); 
        // inflate the layout
        inSnow = (EditText) view.findViewById(R.id.inchesSnow);
        // use the inflated view object to initialize edittext 
        durnStorm = (EditText)view.findViewById(R.id.durationStorm);
        pSnow = (EditText) view.findViewById(R.id.peakRate);
        pTime = (EditText)view.findViewById(R.id.peakRateTime);
        fSnow = (EditText)view.findViewById(R.id.finalRate);
        wSpeed = (EditText) view.findViewById(R.id.windSpeed);
        sGround = (EditText) view.findViewById(R.id.snowGround);
        results = (TextView) view.findViewById(R.id.resultView);
        calc = (Button) view.findViewById(R.id.button);

        return view; // return view
      }

将创建视图上的
更改为

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.advfrag_layout, container, false); 
        // inflate the layout
        inSnow = (EditText) view.findViewById(R.id.inchesSnow);
        // use the inflated view object to initialize edittext 
        durnStorm = (EditText)view.findViewById(R.id.durationStorm);
        pSnow = (EditText) view.findViewById(R.id.peakRate);
        pTime = (EditText)view.findViewById(R.id.peakRateTime);
        fSnow = (EditText)view.findViewById(R.id.finalRate);
        wSpeed = (EditText) view.findViewById(R.id.windSpeed);
        sGround = (EditText) view.findViewById(R.id.snowGround);
        results = (TextView) view.findViewById(R.id.resultView);
        calc = (Button) view.findViewById(R.id.button);

        return view; // return view
      }

您需要初始化正在使用的视图，以便它知道在哪里可以找到您的编辑文本。
您需要初始化正在使用的视图，以便它知道在哪里可以找到您