Activity 中的错误空对象引用

Question

执行此 activity 时得到 "Attempt to invoke virtual method 'boolean java.lang.String.equals (java.lang.Object)' on a null object reference"，可能我的布局中缺少某些内容。请帮我解决这个问题，这是我目前的 layout.xml :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.sbi.mvicall.SettingPageActivity">
<include
    android:id="@+id/toolbar"
    layout="@layout/view_toolbar"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="10dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/language"
            android:textSize="16sp"/>
        <Spinner
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/language"
            android:spinnerMode="dropdown"
            android:layout_weight="1">

        </Spinner>
    </LinearLayout>
    <view
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@color/grey_e4e4e4"
        android:layout_marginRight="10dp"
        android:layout_marginLeft="10dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="10dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/about"
            android:id="@+id/about"
            android:textSize="16sp"/>

    </LinearLayout>

这是我的 layout.java :

package com.sbi.mvicall;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class SettingPageActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_setting_page);
}
}

这是错误日志：

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.sbi.mvicall, PID: 1086
              java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sbi.mvicall/com.sbi.mvicall.SettingPageActivity}: android.view.InflateException: Binary XML file line #30: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2984)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3045)
                  at android.app.ActivityThread.-wrap14(ActivityThread.java)
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1642)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:154)
                  at android.app.ActivityThread.main(ActivityThread.java:6776)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)
               Caused by: android.view.InflateException: Binary XML file line #30: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
               Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
                  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:768)
                  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:734)
                  at android.view.LayoutInflater.rInflate(LayoutInflater.java:865)
                  at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:828)
                  at android.view.LayoutInflater.rInflate(LayoutInflater.java:873)
                  at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:828)
                  at android.view.LayoutInflater.inflate(LayoutInflater.java:525)
                  at android.view.LayoutInflater.inflate(LayoutInflater.java:427)
                  at android.view.LayoutInflater.inflate(LayoutInflater.java:378)
                  at android.support.v7.app.k.b(AppCompatDelegateImplV9.java:287)
                  at android.support.v7.app.c.setContentView(AppCompatActivity.java:139)
                  at com.sbi.mvicall.SettingPageActivity.onCreate(SettingPageActivity.java:11)
                  at android.app.Activity.performCreate(Activity.java:6955)
                  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1126)
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2927)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3045)
                  at android.app.ActivityThread.-wrap14(ActivityThread.java)
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1642)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:154)
                  at android.app.ActivityThread.main(ActivityThread.java:6776)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)

Answer 1

在您的 XML 布局中，将 view 更改为 View（使用大写字母）

<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="@color/grey_e4e4e4"
    android:layout_marginRight="10dp"
    android:layout_marginLeft="10dp"/>

Activity 中的错误空对象引用

Error null object reference in Activity

android

nullreferenceexception