Java 多个活动错误Android-尝试调用虚拟方法''；关于空对象引用

首先，请原谅我的英语不好

我是android新手，我正在创建一个基本的室内地图，有多个没有GPS或互联网连接的活动，前9个活动进行得很顺利，所有活动都进行得很顺利，但后来我在列表中添加了活动编号10，一切正常，没有错误，即使在调试程序时，但当我试图使用按钮进入我添加的最后一个活动时，应用程序停止工作，在run窗口中，我收到了这条消息

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.erick.marriotmap/com.example.erick.marriotmap.m401_425}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

如果我尝试将另一个活动连接到另一个按钮，但总共超过9个活动，那么这个问题总是存在的

按钮如下：

<Button
            android:text="stairs"
            android:textSize="8dp"
            android:layout_width="57dp"
            android:layout_height="31dp"
            android:id="@+id/btn_stairs3"
            android:layout_marginTop="100dp"
            android:layout_row="0"
            android:layout_column="0" />

bstairs3.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr3  = new Intent(m501_517.this, m401_425.class);
                startActivity(bstr3);
            }
        });

这是所有参考代码

班级：

package com.example.erick.marriotmap;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;

public class m501_517 extends AppCompatActivity {
    Button blobby;
    Button bstaira1;
    Button bstairs2;
    Button bstairs3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_m501_517);

        bstaira1 = (Button) findViewById(R.id.btn_stairs1);
        bstairs2 = (Button) findViewById(R.id.btn_stairs2);
        bstairs3 = (Button) findViewById(R.id.btn_stairs3);
        blobby = (Button) findViewById(R.id.btn_lobby);

        bstaira1.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr1  = new Intent(m501_517.this, m601_608.class);
                startActivity(bstr1);
            }
        });

        bstairs2.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr2  = new Intent(m501_517.this, m601_608.class);
                startActivity(bstr2);
            }
        });

        bstairs3.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr3  = new Intent(m501_517.this, m401_425.class);
                startActivity(bstr3);
            }
        });


        blobby.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent blobby  = new Intent(m501_517.this, mlobby_quinto.class);
                startActivity(blobby);
            }
        });

    }
}

活动：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.erick.marriotmap.m501_517"
    android:background="@drawable/p601_608"
    android:weightSum="1"
    android:baselineAligned="false">


    <GridLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/p501_517">

        <Button
            android:text="Stairs"
            android:textSize="8dp"
            android:layout_width="57dp"
            android:layout_height="31dp"
            android:id="@+id/btn_stairs2"
            android:layout_row="1"
            android:layout_column="1"
            android:layout_marginLeft="235dp"
            android:layout_marginTop="30dp" />

        <Button
            android:text="stairs"
            android:textSize="8dp"
            android:layout_width="57dp"
            android:layout_height="31dp"
            android:id="@+id/btn_stairs3"
            android:layout_marginTop="100dp"
            android:layout_row="0"
            android:layout_column="0" />

        <Button
            android:text="lobby"
            android:textSize="8dp"
            android:layout_width="50dp"
            android:layout_height="34dp"
            android:id="@+id/btn_lobby"
            android:layout_row="0"
            android:layout_column="2"
            android:layout_marginBottom="0dp"
            android:layout_marginLeft="215dp"
            android:layout_marginTop="150dp" />

        <Button
            android:text="stairs"
            android:textSize="8dp"
            android:layout_width="57dp"
            android:layout_height="31dp"
            android:id="@+id/btn_stairs1"
            android:layout_row="1"
            android:layout_column="2"
            android:layout_marginBottom="0dp"
            android:layout_marginLeft="230dp"
            android:layout_marginTop="30dp" />
    </GridLayout>

</LinearLayout>

这是我的舱单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.erick.marriotmap">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:resizeableActivity="false" android:label="Sexto piso - Lobby" android:screenOrientation="portrait" android:name=".map"></activity>

        <activity android:resizeableActivity="false" android:label="Sexto piso - Habitaciones 601 - 608" android:screenOrientation="landscape" android:name=".m601_608"></activity>
        <activity android:resizeableActivity="false" android:label="Sexto piso - Habitaciones 626 - 640" android:screenOrientation="landscape" android:name=".m626_640"></activity>
        <activity android:resizeableActivity="false" android:label="Quinto piso - Lobby" android:screenOrientation="portrait" android:name=".mlobby_quinto"></activity>
        <activity android:resizeableActivity="false" android:label="Quinto piso - Habitaciones 526 - 549" android:screenOrientation="landscape" android:name=".m526_549"></activity>
        <activity android:resizeableActivity="false" android:label="Septimo piso - Lobby" android:screenOrientation="landscape" android:name=".mlobby_septimo"></activity>
        <activity android:resizeableActivity="false" android:label="Septimo piso - Habitaciones 726 - 733" android:screenOrientation="landscape" android:name=".m726_733"></activity>
        <activity android:resizeableActivity="false"  android:label="Quinto piso - Habitaciones 501 - 517" android:screenOrientation="landscape" android:name=".m501_517"></activity>

        <activity android:resizeableActivity="false"  android:label="Cuarto piso - Habitaciones 401 - 425" android:screenOrientation="landscape" android:name=".m401_425"></activity>
    </application>

</manifest>

---

我知道这是一篇很长的帖子，我知道会有人说这个问题已经得到了回答，但我找不到解决我问题的好答案，男孩女孩们，我需要你们的帮助

xml布局的名称是什么？是“activity_m401_425”吗？带有按钮的xml的名称是activity_m501_517，布局目标是activity_m401_425; xml布局的名称是什么？是否为“activity_m401_425”？带有按钮的xml名称为activity_m501_517，布局目标为activity_m401_425

package com.example.erick.marriotmap;


import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;

public class m401_425 extends AppCompatActivity {
    Button bkids;
    Button bstairs1;
    Button bstairs2;
    Button bstairs3;
    Button bstairs4;
    Button bstairs5;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_m401_425);

        bstairs1 = (Button) findViewById(R.id.btn_str1);
        bstairs2 = (Button) findViewById(R.id.btn_str2);
        bstairs3 = (Button) findViewById(R.id.btn_str3);
        bstairs4 = (Button) findViewById(R.id.btn_str4);
        bstairs5 = (Button) findViewById(R.id.btn_str5);
        bkids = (Button) findViewById(R.id.btn_lobby);

        bstairs1.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr1  = new Intent(m401_425.this, m501_517.class);
                startActivity(bstr1);
            }
        });

        bstairs2.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr2  = new Intent(m401_425.this, m501_517.class);
                startActivity(bstr2);
            }
        });

        bstairs3.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr3  = new Intent(m401_425.this, m501_517.class);
                startActivity(bstr3);
            }
        });
        bstairs4.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr3  = new Intent(m401_425.this, m501_517.class);
                startActivity(bstr3);
            }
        });
        bstairs5.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bstr3  = new Intent(m401_425.this, m501_517.class);
                startActivity(bstr3);
            }
        });


        bkids.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {

                Intent bkids  = new Intent(m401_425.this, map.class);
                startActivity(bkids);
            }
        });

    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.erick.marriotmap">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:resizeableActivity="false" android:label="Sexto piso - Lobby" android:screenOrientation="portrait" android:name=".map"></activity>

        <activity android:resizeableActivity="false" android:label="Sexto piso - Habitaciones 601 - 608" android:screenOrientation="landscape" android:name=".m601_608"></activity>
        <activity android:resizeableActivity="false" android:label="Sexto piso - Habitaciones 626 - 640" android:screenOrientation="landscape" android:name=".m626_640"></activity>
        <activity android:resizeableActivity="false" android:label="Quinto piso - Lobby" android:screenOrientation="portrait" android:name=".mlobby_quinto"></activity>
        <activity android:resizeableActivity="false" android:label="Quinto piso - Habitaciones 526 - 549" android:screenOrientation="landscape" android:name=".m526_549"></activity>
        <activity android:resizeableActivity="false" android:label="Septimo piso - Lobby" android:screenOrientation="landscape" android:name=".mlobby_septimo"></activity>
        <activity android:resizeableActivity="false" android:label="Septimo piso - Habitaciones 726 - 733" android:screenOrientation="landscape" android:name=".m726_733"></activity>
        <activity android:resizeableActivity="false"  android:label="Quinto piso - Habitaciones 501 - 517" android:screenOrientation="landscape" android:name=".m501_517"></activity>

        <activity android:resizeableActivity="false"  android:label="Cuarto piso - Habitaciones 401 - 425" android:screenOrientation="landscape" android:name=".m401_425"></activity>
    </application>

</manifest>