React Native FlatList with columns, Last item width

问题

I'm using a FlatList to show a list of items in two columns

<FlatList style={{margin:5}}
  data={this.state.items}
  numColumns={2}
  keyExtractor={(item, index) => item.id }
  renderItem={(item) => <Card image={item.item.gallery_image_url} text={item.item.name}/> }
/>

The card component is just a view with some styles:

<View style={{ flex: 1, margin: 5, backgroundColor: '#ddd', height: 130}} ></View>

It is working fine, but if the number of items is odd, the last row only contains one item and that item stretches to the full width of the screen.

How can I set the item to the same width of the others?

回答1:

Theres a few things you can try here.

A) Setting a pre-defined width for the card ( Maybe equal to the height you've set? ). Then you can use alignItems in order to have the card positioned in the middle or on the left - Unsure as to which you wanted here.

B) If there are an even number of cards, you could add an empty View at the end in order to fill this space. I find this method pretty clunky but useful when trying to leave space for future elements.

C) Simply use alignItems: 'space-between, i like to use this to center items, but you would have to define the width, or use something like flex:0.5

I suggest researching more into flexbox to help you with this, as it is hard to tell the context of this situation. I'm assuming the above methods will help, but if not, here are some links for you to look at -

First link

Second link

~~Third link~~ _{Link Broken}

Hope this helps. If you need any further clarification - just ask

回答2:

for your case use flex: 1/2

therefore: Your item should have flex of 1/(number of columns) if you have 3 columns your item should have flex:1/3

回答3:

You can try to get the current width of the device via Dimensions, do some math based on the number of columns you want to render, minus off the margins and set that as the minWidth and maxWidth.

For example:

const {height, width} = Dimensions.get('window');
const itemWidth = (width - 15) / 2;

<View style={{ flex: 1, margin: 5, backgroundColor: '#ddd', minWidth: {this.itemWidth}, maxWidth: {this.itemWidth}, height: 130}} ></View>

回答4:

This is the cleanest way to style a `FlatList` with columns and spaced evenly:

    <FlatList style={{margin:5}}
        numColumns={2}                  // set number of columns 
        columnWrapperStyle={style.row}  // space them out evenly

        data={this.state.items}
        keyExtractor={(item, index) => item.id }
        renderItem={(item) => <Card image={item.item.gallery_image_url} text={item.item.name}/> }
    />       

    const style = StyleSheet.create({
        row: {
            flex: 1,
            justifyContent: "space-around"
        }
    });

回答5:

The reason for it is your Card have style flex: 1, so it will try to expand all the space remain. You can fix it by add maxWidth: '50%' to your Card style

<View style={{ flex: 1, margin: 5, backgroundColor: '#ddd', height: 130, maxWidth: '50%'}} ></View>

回答6:

check whether the number of items is odd, if the number is odd, give a special style to the last item. eg)

 {this.props.count%2!= 0?
                <View style={this.props.entireList.indexOf(item) === this.props.entireList.length-1 ?stles.v1:styles.v2}></View>
 v1:{
 width:'48%'
}
v2:{
}

来源：https://stackoverflow.com/questions/43502954/react-native-flatlist-with-columns-last-item-width

标签

react-native

react-native-flatlist