偏好设置屏幕启动时，Android App立即崩溃

Question

我一直在为应用程序设置首选项屏幕，甚至在崩溃之前都没有显示它。 我检查了一些有关共享首选项的教程，我的代码与它们相似，但是没有任何效果。 我认为问题出在我的preferences.xml文件中，因为我注释掉了除在PreferenceActivity中打开XML文件以外的所有内容。

这是我的preferences.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
  xmlns:android="http://schemas.android.com/apk/res/android">
  <PreferenceCategory
    android:title="Password">
    <EditTextPreference
        android:name="Your Password"
        android:title="Password"
        android:defaultValue=""
        android:summary="For logging in if facial recognition fails"
        android:key="password" />
    <EditTextPreference
        android:name="Max Attempts"
        android:title="Max Attempts"
        android:defaultValue="3"
        android:summary="Max number of times to try authentication before falling back to password"
        android:key="maxAttempts" />
  </PreferenceCategory>
  <PreferenceCategory
    android:title="Security">
    <CheckBoxPreference
        android:title="Intruder Alert"
        android:defaultValue="false"
        android:summary="Notify me if you detect a face other than mine"
        android:key="intruderAlert" />
        </PreferenceCategory>
    <PreferenceCategory
        android:title="Intruder Notification">
        <EditTextPreference
        android:name="Your Email"
        android:title="email"
        android:defaultValue=""
        android:summary="An email address for us to notify"
        android:key="email" />
        <EditTextPreference
        android:name="Your Phone Number"
        android:title="phoneNumber"
        android:defaultValue=""
        android:summary="A phone number for us to notify"
        android:key="phoneNumber" />            
        </PreferenceCategory>
</PreferenceScreen>

而且，如果我错了并且我的问题是我的java文件，这是PreferenceActivity。 目前大多数注释已被注释掉，但该程序仍然崩溃。

public class Preferences extends PreferenceActivity implements OnSharedPreferenceChangeListener {

    /*private EditTextPreference password;
    private EditTextPreference maxAttempts;
    private CheckBoxPreference intruderAlert;
    private EditTextPreference email;
    private EditTextPreference phoneNumber;

    String PassWord;
    int MaxAttempts;
    boolean IntruderAlert;
    String Email;
    String PhoneNumber;*/

    @Override
    public void onCreate(Bundle savedInstanceState) 
    {   
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);  
        //password = (EditTextPreference) getPreferenceScreen().findPreference("password");
        //maxAttempts = (EditTextPreference) getPreferenceScreen().findPreference("maxAttempts");
        //intruderAlert = (CheckBoxPreference) getPreferenceScreen().findPreference("intruderAlert");
        //email = (EditTextPreference) getPreferenceScreen().findPreference("email");
        //phoneNumber = (EditTextPreference) getPreferenceScreen().findPreference("phoneNumber");
    }

    private void setSummaries()
    {

    }

    @Override
    protected void onResume() 
    {
        /*super.onResume();
        String intruderAlertSetting;
        if (intruderAlert.isChecked())
            intruderAlertSetting = "on";
        else
            intruderAlertSetting = "off";
        password.setSummary("Your password is " +password.getText()+ ".");
        maxAttempts.setSummary("The max attempts that will be made is "+maxAttempts.getText() + ".");
        intruderAlert.setSummary("You have intruder alert set to" + intruderAlertSetting+".");
        if (email.getText().equals(""))
            email.setSummary("You have no email address stored.");
        else
            email.setSummary("Your stored email address is "+email.getText() + ".");
        if (phoneNumber.getText().equals(""))
            phoneNumber.setSummary("You have no phone number stored.");
        else
            phoneNumber.setSummary("Your stored phone number is " + phoneNumber.getText()+".");
        // Set up a listener whenever a key changes
        getPreferenceScreen().getSharedPreferences()
                .registerOnSharedPreferenceChangeListener(this);*/

    }

    @Override
    protected void onPause() 
    {
        /*super.onPause();

        String intruderAlertSetting;
        if (intruderAlert.isChecked())
            intruderAlertSetting = "on";
        else
            intruderAlertSetting = "off";
        password.setSummary("Your password is " +password.getText()+ ".");
        maxAttempts.setSummary("The max attempts that will be made is "+maxAttempts.getText() + ".");
        intruderAlert.setSummary("You have intruder alert set to" + intruderAlertSetting+".");
        if (email.getText().equals(""))
            email.setSummary("You have no email address stored.");
        else
            email.setSummary("Your stored email address is "+email.getText() + ".");
        if (phoneNumber.getText().equals(""))
            phoneNumber.setSummary("You have no phone number stored.");
        else
            phoneNumber.setSummary("Your stored phone number is " + phoneNumber.getText()+".");

        // Unregister the listener whenever a key changes
        getPreferenceScreen().getSharedPreferences()
                .unregisterOnSharedPreferenceChangeListener(this);*/
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,String key) 
    {
        /*String intruderAlertSetting;
        if (intruderAlert.isChecked())
            intruderAlertSetting = "on";
        else
            intruderAlertSetting = "off";
        password.setSummary("Your password is " +password.getText()+ ".");
        maxAttempts.setSummary("The max attempts that will be made is "+maxAttempts.getText() + ".");
        intruderAlert.setSummary("You have intruder alert set to" + intruderAlertSetting+".");
        if (email.getText().equals(""))
            email.setSummary("You have no email address stored.");
        else
            email.setSummary("Your stored email address is "+email.getText() + ".");
        if (phoneNumber.getText().equals(""))
            phoneNumber.setSummary("You have no phone number stored.");
        else
            phoneNumber.setSummary("Your stored phone number is " + phoneNumber.getText()+".");
        PassWord = password.getText();
        MaxAttempts = Integer.parseInt(maxAttempts.getText());
        IntruderAlert = intruderAlert.isChecked();
        Email = email.getText();
        PhoneNumber = phoneNumber.getText();*/

    }   
}

这是关于崩溃的LogCat信息：

04-23 16:37:09.181: WARN/dalvikvm(818): threadid=1: thread exiting with uncaught exception (group=0x40015560)
04-23 16:37:09.221: ERROR/AndroidRuntime(818): FATAL EXCEPTION: main
04-23 16:37:09.221: ERROR/AndroidRuntime(818): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cs.fsu.edu.project4/com.cs.fsu.edu.project4.Preferences}: android.view.InflateException: Binary XML file line #2: Error inflating class PreferenceScreen
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1622)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1638)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:928)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.os.Looper.loop(Looper.java:123)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.ActivityThread.main(ActivityThread.java:3647)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at java.lang.reflect.Method.invokeNative(Native Method)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at java.lang.reflect.Method.invoke(Method.java:507)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at dalvik.system.NativeStart.main(Native Method)
04-23 16:37:09.221: ERROR/AndroidRuntime(818): Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class PreferenceScreen
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.inflate(LayoutInflater.java:386)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:207)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.Activity.setContentView(Activity.java:1657)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at com.cs.fsu.edu.project4.Preferences.onCreate(Preferences.java:33)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1586)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     ... 11 more
04-23 16:37:09.221: ERROR/AndroidRuntime(818): Caused by: java.lang.ClassNotFoundException: android.view.PreferenceScreen in loader dalvik.system.PathClassLoader[/data/app/com.cs.fsu.edu.project4-1.apk]
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.createView(LayoutInflater.java:471)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.onCreateView(LayoutInflater.java:549)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568)
04-23 16:37:09.221: ERROR/AndroidRuntime(818):     ... 19 more
04-23 16:37:09.251: WARN/ActivityManager(62):   Force finishing activity com.cs.fsu.edu.project4/.Preferences

Answer 1

在您的偏好活动onCreate中，您可能有以下内容：

setContentView(R.xml.prefs);

您需要这样的东西：

addPreferencesFromResource(R.xml.prefs);

引用： 找不到PreferenceScreen类

Answer 2

也许您更改了首选项架构，请尝试删除存储在/ dbdata / databases / com_your_app / shared_prefs /或/ data / data / com_your_app中的旧偏好文件。

Answer 3

确保您具有AndroidManifest.xml文件中列出的活动

<activity android:name=".Preferences"></activity>

Answer 4

应用程序以某种方式认为PreferenceScreen是android.view包的，但系统文档仅在android.preference包中知道它

 Caused by: java.lang.ClassNotFoundException: android.view.PreferenceScreen in loader dalvik.system.PathClassLoader[/data/app/com.cs.fsu.edu.project4-1.apk]

您是否以某种方式在应用程序中添加了一个名为PreferenceScreen的类，这可能会使系统感到困惑？

Answer 5

我想在这里加分。 我的经验是，始终进行干净的构建，始终检查清单中的意图，活动，过滤器和权限。

检查软件包名称，有时您重命名了可能会出错的软件包。

在安装之前，请删除以前的应用程序（是在其他PC上创建的吗？），然后删除旧设置。

这一切都让我错了:-)

如果这不起作用，请将所有文件复制到新项目。 愚蠢，但这对我有用-对所有内容都未加注释，但仍然无效。 然后：ping，启动并开始。