ClassNotFoundException的在android.util.ArrayMap里面意向 [英] ClassNotFoundException in android.util.ArrayMap inside Intent

问题描述

我是开发一个Android应用程序，并在部分之一，我通过使用一个Intent数据从一个datepicker对话片段回，使用getTargetFragment（）创​​建它的片段。onActivityResult（INT targetRequest code，INT结果code，意图意图）。我加入三个整数（日，月，年）从日历片段提取到的意图传递。然后我读创建它的片段的onActivityResult（）方法，在此意图。一切正常，因为它应该，一切都很好，很正常，世界是生活在一个完美的地方。

I was developing an Android app and in one of the sections, I pass data using an Intent from a DatePicker dialog fragment back to the fragment that created it using getTargetFragment().onActivityResult(int targetRequestCode, int resultCode, Intent intent). I am adding three integers (date, month and year) extracted from the Calendar fragment to the intent being passed. And then I read this intent within the onActivityResult() method of the fragment that created it. Everything works as it should and all is fine and dandy and the world is a perfect place to live in.

当我试图调试，我犯了一个愚蠢的错误，我注意到一些有趣的事情。当我展开意图的内容，我觉得我的数据是一个捆绑的预期。但是，我看到有意向在另一个对象调用android.util.ArrayMap大小为3。

While I was trying to debug a silly error that I had made, I noticed something interesting. When I expand the content of the intent, I find that my data is in a bundle as expected. But I see that there is another object within the intent called android.util.ArrayMap with size 3.

此大小似乎对应于我把在意图（Ⅰ通过添加额外的虚设参数测试它）数据的数量。当我展开ArrayMap的内容，我看到它抛出一个ClassNotFoundException。为什么会做到这一点。密钥类型为String，值类型为整型（我把一个int，但我不认为它很重要，因为我加入的String键和值，它仍然抛出异常）。我扩大了ArrayMap细节，但它似乎没有什么意义。

This size seems to correspond to the number of data that I put in the intent (I tested it by adding additional dummy parameters). when I expand the contents of the ArrayMap, I see that it throws a ClassNotFoundException. Why would it do this. The key type is String and the value type is Integer (I am putting an int but I don't think it matters as I added in String for key and value and it still threw the exception). I expanded the ArrayMap details but it did not seem to make sense.

我的问题是：

• 这是为什么ClassNotFoundException的发生？
• 什么是摆在首位的必要性ArrayMap？

推荐答案

你的 putExtra 值保存在捆绑的内部数据结构，这恰好是 ArrayMap

your putExtra values are saved inside Bundle's internal data structure , which happens to be ArrayMap

下面是其定义在 Bundle.java声明源

    // Invariant - exactly one of mMap / mParcelledData will be null
    // (except inside a call to unparcel)

    /* package */ ArrayMap<String, Object> mMap = null;

我想这将您 INT 来一个更通用的对象类。

I guess it converts your int to a more generic Object class.

ClassNotFoundException的可能是IDE /调试窗口的问题，因为没有任何其他的自定义类在这里的这个数据结构。此外，你是<一个href="http://developer.android.com/reference/android/content/Intent.html#putExtra(java.lang.String,%20int)"相对=nofollow>预计将使用包名preFIX在名称，这里提到

ClassNotFoundException could be IDE/debug window issue, as there is not any other custom class here for this data structure. Also, you are expected to use package-name prefix in your name, as mentioned here

The name must include a package prefix, for example the app com.android.contacts would use names like "com.android.contacts.ShowAll".

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