README.md
1# Gallery Widget
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3### Introduction
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5This sample demonstrates the display of **Gallery** images in a widget and periodic update of the widget. The display effect is as follows:
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9### Concepts
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11Media library management: You can use **getAllObject** of the media library instance to query the paths of all images in **Gallery**, and use **open** to obtain the file descriptor (FD) of an image in the specified path. This FD will be used as a key parameter for creating a widget.
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13Widget update: You can use **formProvider.setFormNextRefreshTime** to set the next refresh time (5 minutes at minimum) for a widget. After the specified time elapsed, the **onUpdate** callback is invoked to update the widget.
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15### Required Permissions
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17**ohos.permission.MEDIA_LOCATION**, which allows an app to access geographical locations in the user's media file.
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19**ohos.permission.READ_MEDIA**, which allows an app to read media files from the user's external storage.
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21**ohos.permission.WRITE_MEDIA**, which allows an app to read media files from and write media files into the user's external storage.
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23### Usage
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251. When you start the app for the first time, you must grant the app the permission to access the geographical location information in your media file.
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272. Touch and hold the app icon to create a widget and add the widget to the home screen. The widget displays images in **Gallery** properly.
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293. Touch the image displayed on the widget to start the app.
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31### Constraints
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331. This sample can only be run on standard-system devices.
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352. This sample is based on the stage model, which is supported from API version 9.
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373. DevEco Studio 3.0 Beta3 (Build version: 3.0.0.992, built on July 6, 2022) must be used.
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394. Before creating a widget, ensure that there are images in **Gallery**. Otherwise, the widget will not be updated.
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415. The update takes place 5 minutes after the widget is created when the device screen is on.
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