当Android的isValidFragment（）从preferenceActivity被调用？ [英] when android's isValidFragment() from PreferenceActivity gets called?
问题描述
对于某些应用上，我是工作，对于设备与API级别19我得到异常
致：java.lang.RuntimeException的：的preferenceActivity子类必须覆盖isValidFragment（字符串），以验证该片段类是有效的！玉米......没有如果片段COM ... $检查。已验证。
然后，我发现这些应用程序的Android框架保护布尔isValidFragment（字符串fragmentName）获取调用，其中有code
如果（getApplicationInfo（）targetSdkVersion＆GT; = android.os.Build.VERSION_ codeS.KITKAT）{
抛出新的RuntimeException（
的preferenceActivity子类必须覆盖isValidFragment（字符串）
+来验证该片段类是有效！+ this.getClass（）。的getName（）
+ fragmentName +是有效的。+如果片段没有检查）;
} 其他 {
返回true;
}
然后我试图复制错误
我把我的示例应用程序的code从 preferences活动示例
并加入行＆LT;使用-SDK机器人：targetSdkVersion =19/＆GT; 在清单
但奇怪的是，我没有收到错误（isValidFragment（）不获取调用在这种情况下）。
所以，请告诉我如何复制的错误在我的示例应用程序。
好像是一个错误或4.4安全限制。 Workaraound是使用低于19任何仍与 preferenceActivity 兼容，然后硬着头皮用于与旧的目标进行编译。
我是用头模式为preferenceActivity（覆盖公共无效onBuildHeaders（名单＆LT;头＆GT;目标）），我假设OP是也极有可能是在地方，事情发生和崩溃。
在我的情况，我已经缩小这一例外＆LT;使用-SDK机器人：targetSdkVersion =19/＆GT; ，并在什么[14-18]构建目标将编译及运行没有问题。
建议（用于Eclipse）：我从来没有搞砸直接搞砸这样的东西，但我如果您编译 preferenceActivity （也许片段）就任不同的项目，针对18岁或以下（双关语不打算：O），然后使用该项目作为库作为你的目标奇巧（19）主体工程，也许就能避免死机的情况在运行 - 时间，同时还使用从最新版本需要的功能（只要这些功能在构建-18结合 preferenceActivity ）。如果这没有成功，请尝试使用该项目中的罐的形式（pre-编译）而不是使用项目作为库。</ P>
更新：还注意到卡米尔塞维尼的回答。如果问题有什么关系，其他问题（50％的机会恕我直言），针对18 API所有应用程序都容易受到片段注入式攻击（看他的链接的问题）。
For some application on which I was working, for devices with API level 19 I'm getting exception
Caused by: java.lang.RuntimeException: Subclasses of PreferenceActivity must override isValidFragment(String) to verify that the Fragment class is valid! com... has not checked if fragment com...$. is valid.
Then, I found out that for those applications android frameworks protected boolean isValidFragment(String fragmentName) is getting called, which has code
if (getApplicationInfo().targetSdkVersion >= android.os.Build.VERSION_CODES.KITKAT) {
throw new RuntimeException(
"Subclasses of PreferenceActivity must override isValidFragment(String)"
+ " to verify that the Fragment class is valid! " + this.getClass().getName()
+ " has not checked if fragment " + fragmentName + " is valid.");
} else {
return true;
}
Then I tried to replicate the error
I took my sample app's code from Preferences Activity Example
and added line <uses-sdk android:targetSdkVersion="19" /> in manifest.
But strangely, I'm not getting the error(isValidFragment() not getting called in that case).
So please tell me how to replicate that error in my sample app.
Seems to be a bug or a 4.4 security restriction. Workaraound is to use anything below 19 that is still compatible with PreferenceActivity, and bite the bullet for compiling with an older target.
I am using the headers "pattern" for the PreferenceActivity (overriding public void onBuildHeaders(List<Header> target)), and I assume the OP is too, most likely being the place where stuff happens and crashes.
In my case, I have narrowed this exception to <uses-sdk android:targetSdkVersion="19" />, and anything in [14-18] build targets will compile and run without issues.
Suggestion (for Eclipse): I never messed directly messed with such stuff, but I'm assuming if you compile your PreferenceActivity (and maybe fragments) on a different project, targeting 18 or under (pun not intended :O ), and then using that project as a library for your main project targeting KitKat (19), perhaps you can avoid the crash scenario at run-time while still using the features you need from the latest build (as long as those features aren't in the build-18-bound PreferenceActivity). If this does not succeed, try with that project in jar form (pre-compiled) instead of using project as library.
UPDATE: also take note of Camille Sévigny's answer. If the issue has anything to do with that other question (50% chance IMHO), all apps targeting API 18 are vulnerable to fragment injection attacks (see his linked question).
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