<ScrollView
onScroll={(event)=>{
const top = event.nativeEvent.contentOffset.y;
setTop(top);
}}
>
With my code above contentOffset y updated only when scroll ScrollView abruptly without holding my finger up to ScrollView but if I hold my finger up when scroll the contentOffset y doesn't updated.
I noticed this happening for all onScroll function.
What I want to achieve:
I want on scroll ScrollView contentOffset y update.
Using Animated.ScrollView instead of ScrollView maybe help you. Have a look at this https://eveningkid.medium.com/animated-and-react-native-scrollviews-de701f1b1ce5
Related
i'm using createMaterialTopTabNavigator with a swipeEnabled set to True to navigate between screens, I have a Screen which contains an horizontal scrollView, the problems is that the scrollView isn't working, since whenever i try to scroll it horizontally the screen just changes to the next one.
I'd like to be able to disable the swipeEnabled when i swipe in the scrollView.
PS: i tried doing it dynamically by passing a variable to the Screen and a method that sets it to false using onTouchStart, but it's slower than the swiping event of the screen so it end up swiping to the next screen before onTouchStart event start.
I have a Flatlist inside a ScrollView with 100 items, but no matter what height I give to the ScrollView or Flatlist, there are always just 18 items displayed on my Phone. After that the slider of the ScrollView is still scrolling down, but the list ends after 18 items. I want to be able to scroll through the complete list of items with the ScrollView containing the FlatList. I am using a Samsung Galaxy S8+ as a test device.
Here is a snack of the problem: https://snack.expo.io/#christophhummler/stickyheaderscrollscreens
Thanks for your help :)
I think it has to do with the scrollEnabled={false}, set it to true or remove the prop altogether otherwise it may be your todos array
Edit
Since you want to create a sticky header you must set the height to be the device height of screen + height of header, change styles.scrollView to :
scrollView: {
height: height + 200,
}
also on android there is an issue of nesting scrollviews, to enable a nested scrollview add the nestedScrollEnabled prop:
<FlatList
...
nestedScrollEnabled={true}
/>
You will have to implement logic to enable the Flatlist scroll view when the specific threshholds are met. It works at the moment in conjunction with scrollEnabled={true}
i hope this helps
I am trying to make it so whenever something new is rendered into a scroll view, the scroll view will stay put and not bump up and down. Right now if a new component is rendered in, the scrollview appears to be reset to 0.
Is there a way to stop this behavior, and hold position?
Right now for the scrollview I am using:
handleScrollt(event){
this.scroll = event.nativeEvent.contentOffset.y
}
handleSizet(width, height){
if (this.scroll) {
const position = this.scroll + height - this.height
this.refs.sv.scrollTo({x: 0, y: position, animated: false})
}
this.height = height
}
<ScrollView
ref="sv"
scrollEventThrottle={16}
onScroll={this.handleScrollt.bind(this)}
onContentSizeChange={this.handleSizet.bind(this)}
The issue with this is the scrollview will render briefly, before then scrolling to the correct offset. So it seems like theres a brief splash of the top of the screen
you have to define a height for the scrollview.
If the scrollview is supposed to cover an entire View you can get the view's height by:
<View style={styles.contactView} onLayout={(event) => {
var contactViewY = event.nativeEvent.layout.y;
this.setState({contactViewY: contactViewY})
}}>
and then give it to the scrollview
<ScrollView style={[styles.contactScroller, {height: this.state.contactViewY}]}>
Bear in mind that the onLayout method is called immediately once the layout has been calculated, so if the view's height changes later, this two lines of code alone won't update it.
You should try maintainVisibleContentPosition.
Example:
<ScrollView
{...props}
maintainVisibleContentPosition={{
minIndexForVisible: 0,
}}
/>
From the docs:
maintainVisibleContentPosition
When set, the scroll view will adjust the scroll position so that the
first child that is currently visible and at or beyond
minIndexForVisible will not change position. This is useful for lists
that are loading content in both directions, e.g. a chat thread, where
new messages coming in might otherwise cause the scroll position to
jump. A value of 0 is common, but other values such as 1 can be used
to skip loading spinners or other content that should not maintain
position.
i'd like to know if it's possible to put a View inside a zoomable ScrollView but when the user zooms the scrollview, the view's size wont change. The view must be inside the scrollview because the image on the scrollview is bigger than the screen and i`ll render the view overlaying the image in a precise x:y position.
thanks
kinda extreme go horse but if you put the prop onScroll inside scrolView you can get the zoom and divide the width/height of the view by the zoomScale
onScroll={(event) => this.setState({ zoomScale:event.nativeEvent.zoomScale})}
After the user does some action I want to scroll to a particular section within a ScrollView, which I'm doing using this code:
this.refs.detailsView.measure((x, y, width, height, pageX, pageY) => {
this.refs.homeScrollView.scrollTo({ x: 0, y: pageY - 64, animated: true });
});
The problem is the "detailsView" View is near the bottom of the ScrollView and on the largest iPhones, scrollTo() ends up scrolling past the bottom of ScrollViews "natural" max scroll point and you can see the ScrollViews background colour (dary grey) as though you over-scrolled using touch gestures...the components in the ScrollView have the green background colour.
Does anyone have a suggestion for how to prevent this "over-scrolling" when using the ScrollView.scrollTo() function?
react-native: v0.36
This disables the scrollview from bouncing past its limit
bounces={false}