Android为什么要更改具有相同ID的EditTexts的值? [英] Why does Android change the value of EditTexts with same id?

问题描述

我有一个包含LinearLayout的Fragment，根据某些业务逻辑，其中会膨胀不同的项目.这些项目中的一个包含一个EditText.当我有多个具有不同内容的项目并且我分离/附加了片段时，所有EditText都会以某种方式获得所有相同的文本.仅当EditText在布局文件中具有ID时，这种情况才会发生.

I have a Fragment containing a LinearLayout where different items are inflated depending on some business logic. On of these items contains an EditText. When I have multiple of these items with different content and I detach/attach the fragment, all EditTexts somehow get all the same text. This only happens as long as the the EditText has an id in the layout file.

为什么会这样?除了删除ID之外，还有其他方法可以防止这种情况吗?我想在充气物品上使用findViewById来访问视图，而不是容易出错的getChildAt.

Why does that happen? Is there any other way to prevent this except removing the id? I would like to use findViewById on my inflated items to access the views instead of error prone getChildAt.

我创建了一个简约的示例，以在 https://github.com/rodja/EditTextValueProblem 上演示该问题

I've created a minimalistic example to demonstrate the problem at https://github.com/rodja/EditTextValueProblem

推荐答案

只需在EditTexts布局定义中设置android:saveEnabled="false"即可对其进行修复.当然，您需要确保自己保存/恢复了内容.因此，这是一种非直觉的解决方法，但它适用于我的情况.尽管如此，整个事情看起来像是一个Android错误:

It can simply be fixed by setting android:saveEnabled="false" in the EditTexts Layout definition. Of course you need to make sure that the content is saved/restored yourself. So this is an non-intuitive work around -- but it works for my case. None the less the entire thing looks like an Android bug:

Android布局系统的一个不错的功能是

A nice feature of the Android layout system is that

ID在整个树中不必唯一[...]

An ID need not be unique throughout the entire tree [...]

如 Android文档所述.这使得代码和布局的重用变得更加简单，并且被开发人员大量使用.我认为视图的保存/恢复实例状态实现使用视图的ID作为存储状态的键，因此它依赖于整个树中的唯一性. WTF?

as stated in the Android documentation. This makes code and layout reuse much simpler and is heavily used by developers. I think the save/restore instance state implementation for views uses the view's ID as the key to store it's state, hence it relies on uniqueness in the entire tree. WTF?

更新

我已经在 GitHub上的示例中添加了ListView，这表明ListView几乎可以肯定地使用了类似的解决方法以防止EditTexts遇到此问题.可以看出，在ListView内输入EditText的文本不会自动恢复.

I have added a ListView to the example at GitHub which demonstrates that the ListView almost certainly uses a similar workaround to prevent EditTexts to run into this problem. As can be seen, text which is entered into an EditText inside a ListView is not automatically restored.

这篇关于Android为什么要更改具有相同ID的EditTexts的值?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！