What is “tools:context” in Android layout files ?

What is “tools:context” in Android layout files ?

Asked on December 14, 2018 in XML.
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  • 3 Answer(s)

    Here is the key:

         Apparently the activity the tools UI editor uses to render your layout to find the right theme based on the activity. The documented here subscribe to that page to keep up to date.

    Answered on December 14, 2018.
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    Solution for “tools:context” in Android layout files:

        The persistence for the “Associated Activity” selection above the layout is basically the attribute. At reunite, a layout is always associated with an activity. It may affiliate with more than one, but at least one. In the tool, the mapping which at runtime will be other direction; an activity can call setContentView layout to display a layout in order to drive convinced features.

        At present, all are using it for one thing: While choosing the right theme to show for a layout since the manifest file can register themes to make use for an activity,again if we notice the activity associated with the layout, then choose right theme to display for the layout. We need to drive additional features – such as rendering the action bar which is affiliated with the activity, a place to add onClick handlers, etc.

        The solution this is a tools: namespace attribute  is that a designtime mapping for use by the tool. The layout should be used by more activities/fragments . We must provide a way to pick a designtime binding such that we can show the right theme; update it at any time like changing our listview and fragment bindings, etc.

        Almost the “tools” namespace is special. It can be ignored by android packaging tool, so nobattributes will be packaged into the APK. We using it for extra metadata in the layout. It is also a case for the attributes to suppress lint warnings are saved as tools:ignore.

    Answered on December 14, 2018.
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    Your needs:

         Usually the aspect is set in a layout XML file on the root element in, and records which activity the layout is affiliated with at designtime, certainly a layout be used by more layout. Some example will be used by the layout editor to choose a default theme, since themes can be defined in the Manifest and are concord with activities, not layouts. The same dot prefix in manifests to specify the activity class without the full application package name as a prefix.

    Answered on December 14, 2018.
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