The most fundamental component for building UI, View is a container that supports layout with flexbox, style, some touch handling, and accessibility controls, and is designed to be nested inside other views and to have 0 to many children of any type. View maps directly to the native view equivalent on whatever platform React is running on, whether that is a UIView, <div>, android.view, etc. This example creates a View that wraps two colored boxes and custom component in a row with padding.
<View style={{flexDirection: 'row', height: 100, padding: 20}}>
<View style={{backgroundColor: 'blue', flex: 0.3}} />
<View style={{backgroundColor: 'red', flex: 0.5}} />
<MyCustomComponent {...customProps} />
</View>
Views are designed to be used with StyleSheets for clarity and performance, although inline styles are also supported.
Props
accessibilityLabel string
Overrides the text that's read by the screen reader when the user interacts with the element. By default, the label is constructed by traversing all the children and accumulating all the Text nodes separated by space.
accessible bool
When true, indicates that the view is an accessibility element. By default, all the touchable elements are accessible.
hitSlop {top: number, left: number, bottom: number, right: number}
This defines how far a touch event can start away from the view. Typical interface guidelines recommend touch targets that are at least 30 - 40 points/density-independent pixels. If a Touchable view has a height of 20 the touchable height can be extended to 40 with hitSlop={{top: 10, bottom: 10, left: 0, right: 0}} NOTE The touch area never extends past the parent view bounds and the Z-index of sibling views always takes precedence if a touch hits two overlapping views.
onAccessibilityTap function
When accessible is true, the system will try to invoke this function when the user performs accessibility tap gesture.
onLayout function
Invoked on mount and layout changes with
{nativeEvent: { layout: {x, y, width, height}}}.
This event is fired immediately once the layout has been calculated, but the new layout may not yet be reflected on the screen at the time the event is received, especially if a layout animation is in progress.
onMagicTap function
When accessible is true, the system will invoke this function when the user performs the magic tap gesture.
onMoveShouldSetResponder function
onMoveShouldSetResponderCapture function
onResponderGrant function
For most touch interactions, you'll simply want to wrap your component in TouchableHighlight or TouchableOpacity. Check out Touchable.js, ScrollResponder.js and ResponderEventPlugin.js for more discussion.
onResponderMove function
onResponderReject function
onResponderRelease function
onResponderTerminate function
onResponderTerminationRequest function
onStartShouldSetResponder function
onStartShouldSetResponderCapture function
pointerEvents enum('box-none', 'none', 'box-only', 'auto')
Controls whether the View can be the target of touch events.
- 'auto': The View can be the target of touch events.
- 'none': The View is never the target of touch events.
- 'box-none': The View is never the target of touch events but it's subviews can be. It behaves like if the view had the following classes in CSS:
.box-none { pointer-events: none; } .box-none * { pointer-events: all; } - 'box-only': The view can be the target of touch events but it's subviews cannot be. It behaves like if the view had the following classes in CSS:
.box-only { pointer-events: all; } .box-only * { pointer-events: none; }
removeClippedSubviews bool
This is a special performance property exposed by RCTView and is useful for scrolling content when there are many subviews, most of which are offscreen. For this property to be effective, it must be applied to a view that contains many subviews that extend outside its bound. The subviews must also have overflow: hidden, as should the containing view (or one of its superviews).
style style
Flexbox...
ShadowPropTypesIOS#style...
Transforms...
backfaceVisibility enum('visible', 'hidden')
backgroundColor color
borderBottomColor color
borderBottomLeftRadius number
borderBottomRightRadius number
borderBottomWidth number
borderColor color
borderLeftColor color
borderLeftWidth number
borderRadius number
borderRightColor color
borderRightWidth number
borderStyle enum('solid', 'dotted', 'dashed')
borderTopColor color
borderTopLeftRadius number
borderTopRightRadius number
borderTopWidth number
borderWidth number
opacity number
overflow enum('visible', 'hidden')
androidelevation number
(Android-only) Sets the elevation of a view, using Android's underlying elevation API. This adds a drop shadow to the item and affects z-order for overlapping views. Only supported on Android 5.0+, has no effect on earlier versions.
testID string
Used to locate this view in end-to-end tests. NB: disables the 'layout-only view removal' optimization for this view!
androidaccessibilityComponentType AccessibilityComponentType
Indicates to accessibility services to treat UI component like a native one. Works for Android only.
androidaccessibilityLiveRegion enum('none', 'polite', 'assertive')
Indicates to accessibility services whether the user should be notified when this view changes. Works for Android API >= 19 only. See http://developer.android.com/reference/android/view/View.html#attr_android:accessibilityLiveRegion for references.
androidcollapsable bool
Views that are only used to layout their children or otherwise don't draw anything may be automatically removed from the native hierarchy as an optimization. Set this property to false to disable this optimization and ensure that this View exists in the native view hierarchy.
androidimportantForAccessibility enum('auto', 'yes', 'no', 'no-hide-descendants')
Controls how view is important for accessibility which is if it fires accessibility events and if it is reported to accessibility services that query the screen. Works for Android only. See http://developer.android.com/reference/android/R.attr.html#importantForAccessibility for references. Possible values: 'auto' - The system determines whether the view is important for accessibility - default (recommended). 'yes' - The view is important for accessibility. 'no' - The view is not important for accessibility. 'no-hide-descendants' - The view is not important for accessibility, nor are any of its descendant views.
androidneedsOffscreenAlphaCompositing bool
Whether this view needs to rendered offscreen and composited with an alpha in order to preserve 100% correct colors and blending behavior. The default (false) falls back to drawing the component and its children with an alpha applied to the paint used to draw each element instead of rendering the full component offscreen and compositing it back with an alpha value. This default may be noticeable and undesired in the case where the View you are setting an opacity on has multiple overlapping elements (e.g. multiple overlapping Views, or text and a background).
Rendering offscreen to preserve correct alpha behavior is extremely expensive and hard to debug for non-native developers, which is why it is not turned on by default. If you do need to enable this property for an animation, consider combining it with renderToHardwareTextureAndroid if the view contents are static (i.e. it doesn't need to be redrawn each frame). If that property is enabled, this View will be rendered off-screen once, saved in a hardware texture, and then composited onto the screen with an alpha each frame without having to switch rendering targets on the GPU.
androidrenderToHardwareTextureAndroid bool
Whether this view should render itself (and all of its children) into a single hardware texture on the GPU.
On Android, this is useful for animations and interactions that only modify opacity, rotation, translation, and/or scale: in those cases, the view doesn't have to be redrawn and display lists don't need to be re-executed. The texture can just be re-used and re-composited with different parameters. The downside is that this can use up limited video memory, so this prop should be set back to false at the end of the interaction/animation.
iosaccessibilityTraits AccessibilityTraits, [object Object]
Provides additional traits to screen reader. By default no traits are provided unless specified otherwise in element
iosshouldRasterizeIOS bool
Whether this view should be rendered as a bitmap before compositing.
On iOS, this is useful for animations and interactions that do not modify this component's dimensions nor its children; for example, when translating the position of a static view, rasterization allows the renderer to reuse a cached bitmap of a static view and quickly composite it during each frame.
Rasterization incurs an off-screen drawing pass and the bitmap consumes memory. Test and measure when using this property.
Examples
'use strict';
var Platform = require('Platform');
var React = require('react');
var ReactNative = require('react-native');
var {
StyleSheet,
Text,
View,
} = ReactNative;
var TouchableWithoutFeedback = require('TouchableWithoutFeedback');
var styles = StyleSheet.create({
box: {
backgroundColor: '#527FE4',
borderColor: '#000033',
borderWidth: 1,
}
});
var ViewBorderStyleExample = React.createClass({
getInitialState() {
return {
showBorder: true
};
},
render() {
return (
<TouchableWithoutFeedback onPress={this._handlePress}>
<View>
<View style={{
borderWidth: 1,
borderStyle: this.state.showBorder ? 'dashed' : null,
padding: 5
}}>
<Text style={{fontSize: 11}}>
Dashed border style
</Text>
</View>
<View style={{
marginTop: 5,
borderWidth: 1,
borderRadius: 5,
borderStyle: this.state.showBorder ? 'dotted' : null,
padding: 5
}}>
<Text style={{fontSize: 11}}>
Dotted border style
</Text>
</View>
</View>
</TouchableWithoutFeedback>
);
},
_handlePress() {
this.setState({showBorder: !this.state.showBorder});
}
});
exports.title = '<View>';
exports.description = 'Basic building block of all UI, examples that ' +
'demonstrate some of the many styles available.';
exports.displayName = 'ViewExample';
exports.examples = [
{
title: 'Background Color',
render: function() {
return (
<View style={{backgroundColor: '#527FE4', padding: 5}}>
<Text style={{fontSize: 11}}>
Blue background
</Text>
</View>
);
},
}, {
title: 'Border',
render: function() {
return (
<View style={{borderColor: '#527FE4', borderWidth: 5, padding: 10}}>
<Text style={{fontSize: 11}}>5px blue border</Text>
</View>
);
},
}, {
title: 'Padding/Margin',
render: function() {
return (
<View style={{borderColor: '#bb0000', borderWidth: 0.5}}>
<View style={[styles.box, {padding: 5}]}>
<Text style={{fontSize: 11}}>5px padding</Text>
</View>
<View style={[styles.box, {margin: 5}]}>
<Text style={{fontSize: 11}}>5px margin</Text>
</View>
<View style={[styles.box, {margin: 5, padding: 5, alignSelf: 'flex-start'}]}>
<Text style={{fontSize: 11}}>
5px margin and padding,
</Text>
<Text style={{fontSize: 11}}>
widthAutonomous=true
</Text>
</View>
</View>
);
},
}, {
title: 'Border Radius',
render: function() {
return (
<View style={{borderWidth: 0.5, borderRadius: 5, padding: 5}}>
<Text style={{fontSize: 11}}>
Too much use of `borderRadius` (especially large radii) on
anything which is scrolling may result in dropped frames.
Use sparingly.
</Text>
</View>
);
},
}, {
title: 'Border Style',
render: function() {
return <ViewBorderStyleExample />;
},
}, {
title: 'Circle with Border Radius',
render: function() {
return (
<View style={{borderRadius: 10, borderWidth: 1, width: 20, height: 20}} />
);
},
}, {
title: 'Overflow',
render: function() {
return (
<View style={{flexDirection: 'row'}}>
<View
style={{
width: 95,
height: 10,
marginRight: 10,
marginBottom: 5,
overflow: 'hidden',
borderWidth: 0.5,
}}>
<View style={{width: 200, height: 20}}>
<Text>Overflow hidden</Text>
</View>
</View>
<View style={{width: 95, height: 10, marginBottom: 5, borderWidth: 0.5}}>
<View style={{width: 200, height: 20}}>
<Text>Overflow visible</Text>
</View>
</View>
</View>
);
},
}, {
title: 'Opacity',
render: function() {
return (
<View>
<View style={{opacity: 0}}><Text>Opacity 0</Text></View>
<View style={{opacity: 0.1}}><Text>Opacity 0.1</Text></View>
<View style={{opacity: 0.3}}><Text>Opacity 0.3</Text></View>
<View style={{opacity: 0.5}}><Text>Opacity 0.5</Text></View>
<View style={{opacity: 0.7}}><Text>Opacity 0.7</Text></View>
<View style={{opacity: 0.9}}><Text>Opacity 0.9</Text></View>
<View style={{opacity: 1}}><Text>Opacity 1</Text></View>
</View>
);
},
},
];