Dimensions
useWindowDimensions
is the preffered API for React components. UnlikeDimensions
, it updates as the window's dimensions update. This works nicely with the React paradigm.
You can get the application window's width and height using below code:
Although dimensions are available immediately, they may change (e.g due to device rotation, foldable devices etc) so any rendering logic or styles that depend on these constants should try to call this function on every render, rather than caching the value (for example, using inline styles rather than setting a value in a
StyleSheet
).
If you are targeting foldable devices or devices which can change the screen size or app window size, you can use the event listener available in the Dimensions module as shown in the below example.
Example
- Function Component
- Class Component
Reference
Methods
addEventListener()
Add an event handler. Supported events:
change
: Fires when a property within theDimensions
object changes. The argument to the event handler is an object withwindow
andscreen
properties whose values are the same as the return values ofDimensions.get('window')
andDimensions.get('screen')
, respectively.
get()
Initial dimensions are set before runApplication
is called so they should be available before any other require's are run, but may be updated later.
Note: Although dimensions are available immediately, they may change (e.g due to device rotation) so any rendering logic or styles that depend on these constants should try to call this function on every render, rather than caching the value (for example, using inline styles rather than setting a value in a
StyleSheet
).
Example: var {height, width} = Dimensions.get('window');
@param {string} dim Name of dimension as defined when calling set
. @returns {Object?} Value for the dimension.
For Android the
window
dimension will exclude the size used by thestatus bar
(if not translucent) andbottom navigation bar
removeEventListener()
Remove an event handler.
set()
This should only be called from native code by sending the didUpdateDimensions event.
@param {object} dims string-keyed object of dimensions to set