为什么我包含的布局的标签返回null? [英] Why is my included layout's tag returning null?

问题描述

使用以下布局，getView(R.id.included).getView(R.id.text_view)得出null.如果我将TextView包围在LinearLayout中，问题将消失.这是怎么回事?

Using the below layouts, getView(R.id.included).getView(R.id.text_view) evaluates to null. If I surround the TextView in a LinearLayout the problem disappears. What's going on here?

layout.xml

layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent">
   <include android:id="@+id/included"
      layout="@layout/included" />
</LinearLayout>

included.xml

included.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView
   android:id="@+id/text_view"/>

推荐答案

<include>并非完全有据可查.

Tor Norbye 写:

Tor Norbye wrote:

<include>标记不是真实视图，因此findByView将找不到它. @id属性(以及您在include标记上设置的任何其他属性)将改为应用到包含布局的根标记上.因此，您的activity.getView(R.id.included1)实际上应该是<TextView>本身.

The <include> tag is not a real view, so findByView will not find it. The @id attribute (and any other attributes you've set on the include tag) gets applied on the root tag of the included layout instead. So your activity.getView(R.id.included1) should in fact be the <TextView> itself.

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