addPrefencesFromResource 导致 ClassCastException
代码：
public class Preferences extends PreferenceActivity {
public static final String PREF_AUTO_UPDATE = "PREF_AUTO_UPDATE";
public static final String PREF_MIN_MAG = "PREF_MIN_MAG";
public static final String PREF_UPDATE_FREQ = "PREF_UPDATE_FREQ";
SharedPreferences prefs;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
Context context = getApplicationContext();
addPreferencesFromResource(R.xml.userprefs);
}
每次切换到首选项活动时，我都会收到运行时错误，导致应用程序崩溃。沿着轨迹我得到：
引起：java.lang.ClassCastException：java.lang.Integer
经过一些调试后，我发现注释掉 addPreferencesFromResource 行可以防止应用程序崩溃，但（显然）不会加载任何 UI 。我几乎从教科书中逐行复制这个例子，但我一生都无法弄清楚我错过了什么。
Code:
public class Preferences extends PreferenceActivity {
public static final String PREF_AUTO_UPDATE = "PREF_AUTO_UPDATE";
public static final String PREF_MIN_MAG = "PREF_MIN_MAG";
public static final String PREF_UPDATE_FREQ = "PREF_UPDATE_FREQ";
SharedPreferences prefs;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
Context context = getApplicationContext();
addPreferencesFromResource(R.xml.userprefs);
}
Every time I switch over to the preferences activity, I get a run time error that crashes my app. Down the trace I get:
Caused by: java.lang.ClassCastException: java.lang.Integer
After doing some debugging I found that commenting out the line addPreferencesFromResource will keep the app from crashing, but (obviously) doesn't load any UI. I'm copying this example pretty much line for line out of a text book and can't figure out for the life of me what I am missing.
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我在玩这个东西并击中了类似的东西。结果我正在执行 putInt，但定义首选项的 xml 文件有一个与相关键连接的 TextEditPreference。据我所知，TextEditPreference 坚持通过 putString/getString 与共享首选项文件进行交互（duh），而我在某处执行的 putInt 已将 app-preferences.xml (/data/data/.xml) 中的一个元素卡住了。 ./shared_prefs/..)，每次调用 addPreferencesFromResource 时都会终止首选项活动。不确定这是否是您的情况，但我认为一旦您发布用户首选项，人们就可以提供帮助，并注意您是否在代码中自己在 TextEditPreference 的键上使用 putInt 或像我（错误地）所做的那样。
I was playing with this stuff and hit kind of the same thing. Turns out I was doing a putInt but then the xml file defining the preferences had a TextEditPreference hooked up with the relevant key. As far as I can tell, TextEditPreference insists on interacting with the sharedpreferences file via putString/getString (duh), and the putInt I did somewhere in playing around had stuck an element in the app-preferences.xml (/data/data/../shared_prefs/..), which kills the preference activity every time it calls addPreferencesFromResource. Not sure if that's what going on in your case, but I think folks can help once you post your userprefs and also note if you are using putInt on the TextEditPreference's key yourself in code or anything like I was (incorrectly) doing.
检查您的资源类型。这可能就是问题所在。
Check your resources type. That could be the problem.