android:id 和 android:labelFor 之间的区别？

Difference between android:id and android:labelFor?

提问by CoDe

I wrote a simple layout which has an EditText, but it's showing the following warning message:

我写了一个简单的布局，它有一个EditText，但它显示了以下警告消息：

“No label views point to this text field”

“没有标签视图指向此文本字段”

While searching I found thisand it solved that warning message, but did not get difference between both attributes android:idand android:labelFor. Any clarification?

在搜索时，我发现了这一点，它解决了该警告消息，但在属性android:id和android:labelFor. 任何澄清？

回答by My God

android:id

Supply an identifier name for this view, to later retrieve it with View.findViewById()or Activity.findViewById(). This must be a resource reference; typically you set this using the @+ syntax to create a new ID resources. For example: android:id="@+id/my_id" which allows you to later retrieve the view with findViewById(R.id.my_id).

Must be a reference to another resource, in the form "@[+][package:]type:name"or to a theme attribute in the form "?[package:][type:]name".

This corresponds to the global attribute resource symbol id.

安卓：id

提供此视图的标识符名称，以便稍后使用View.findViewById()或检索它 Activity.findViewById()。这必须是资源引用；通常，您使用 @+ 语法设置它以创建新的 ID 资源。例如： android:id="@+id/my_id" 允许您稍后使用findViewById(R.id.my_id).

必须是对另一个资源的引用，"@[+][package:]type:name"以“?[package:][type:]name”的形式 或对主题属性的形式。

这对应于全局属性资源符号 id。

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android:labelFor

public static final int labelFor

Specifies the id of a view for which this view serves as a label for accessibility purposes. For example, a TextView before an EditText in the UI usually specifies what infomation is contained in the EditText. Hence, the TextView is a label for the EditText.

Must be an integer value, such as "100".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

Constant Value: 16843718 (0x010103c6)

机器人：标签为

public static final int labelFor

指定视图的 ID，此视图用作可访问性目的的标签。例如，UI 中 EditText 之前的 TextView 通常指定 EditText 中包含哪些信息。因此，TextView 是 EditText 的标签。

必须是整数值，例如“100”。

这也可能是对包含此类型值的资源（以“@[package:]type:name”形式）或主题属性（以“?[package:][type:]name”形式）的引用.

常数值：16843718 (0x010103c6)

UPDATE:

更新：

For example -

例如 -

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical">
    <LinearLayout android:layout_height="wrap_content" 
    android:orientation="vertical" 
    android:layout_width="match_parent">
     <TextView android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:labelFor="@+id/edit_item_name" 
    android:text="Item Name"/>
     <EditText android:id="@+id/edit_item_name" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:hint="Item Name"/>
    </LinearLayout>
  </LinearLayout>

Reference: android:idand android:labelFor.

参考：android:id和android:labelFor。

回答by Jitender Dev

The labelForis an attribute for accessibility options. You assign this to a label so that if, on a form , user clicks a EditTextfield , android can know what to read (TalkBack for low vision users) to user.

该labelFor是辅助功能选项的属性。您将其分配给一个标签，以便如果用户在表单上单击一个EditText字段，android 就可以知道要向用户阅读什么（针对低视力用户的 TalkBack）。

The idSupply an identifier name for this view, to later retrieve it with View.findViewById()or Activity.findViewById().

该id供应的标识符名称这一观点，到后来与检索它View.findViewById()或Activity.findViewById()。

回答by Henry

android:iddefines the ID of this view.

android:id定义此视图的 ID。

android:labelForreferences the ID of another view.

android:labelFor引用另一个视图的 ID。

回答by Benny

If an app's user interface already provides a text label for the editable item, define android:labelForon the labeling Viewto indicate which item the label describes.

如果应用程序的用户界面已经为可编辑项目提供了文本标签，请android:labelFor在标签View上定义以指示标签描述的项目。

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/email_subject_label"
        android:labelFor="@id/email_subject" />
    <EditText
        android:id="@+id/email_subject"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

For more details: Android Accessibility - How to provide content labels

有关更多详细信息：Android 辅助功能 - 如何提供内容标签

回答by ceph3us

in addition to all answers if u don't use xml files for apps this is a brief explanation what for serves VIEW ID :

除了所有的答案，如果你不为应用程序使用 xml 文件，这是一个简短的解释，用于服务 VIEW ID：

(btw in my opinion using xml sucks - my only xml file is manifest :D generated by gradle)

（顺便说一句，我认为使用 xml 很糟糕——我唯一的 xml 文件是清单 :D 由 gradle 生成）

@IdRes - annotation for resource id

@IdRes - 资源 id 的注释

/** define resource id for view */
@IdRes 
int TEXT_VIEW_ID  = "111111";

/** create edit tex in code */
EditText myTextView = new EditText(Context);
/** set view id */
myTextView.setID(TEXT_VIEW_ID);
/** set layout params etc then attach or inflate as u wish to view hierarchy */    

/** use view id to find view */
EditText etFound = (EditText) View.findViewById(TEXT_VIEW_ID);

ps. ID is mandatory to preserve state of hierarchy view when Activity.onSaveInstanceState(Bundle) is used - so if u create in code (VIEW / WIDGET / LAYOUT etc.) don't forget to set it.

附：当使用 Activity.onSaveInstanceState(Bundle) 时，ID 是保留层级视图状态所必需的 - 所以如果你在代码中创建（VIEW / WIDGET / LAYOUT 等）不要忘记设置它。