React Native FlatList 水平模式根本不起作用 [英] React Native FlatList horizontal mode not working at all

问题描述

我正在使用 React Native 0.44.0 并且我正在尝试使用卡片样式布局制作水平 FlatList.无论出于何种原因，无论我做什么，我都无法激活水平模式.它似乎总是垂直渲染...

I am using React Native 0.44.0 and I am attempting to make a horizontal FlatList using a card style layout. For whatever reason, no matter what I do, I cannot get the horizontal mode to activate. It always seems to render vertically...

这是我使用的代码:

 <FlatList
    horizontal={true}
    data={this.state.newsFeed}
    refreshing={this.state.refreshing}
    ref={ref => {
        this.newsFeedListRef = ref;
    }}
    renderItem={this.renderNewsFeedRow.bind(this)}
    keyExtractor={(item, index) => `feed_${index}`}
    onRefresh={this.__handleNewsFeedOnRefresh.bind(this)}
    renderScrollComponent={this.renderScrollComponent.bind(this)}
    ListHeaderComponent={this.renderListHeaderComponent.bind(this)}
    getItemLayout={(data, index) => ({
        index,
        length: ITEM_HEIGHT,
        offset: ITEM_HEIGHT * index + headerBarHeight
    })} />;

我可以发布我的组件渲染的代码，但除了样式的填充和边距之外，它们都没有使用任何东西，所以 flex 或 flexDirection 东西.

I can post the code for my component renders but none of them use anything but padding and margins for style, so flex or flexDirection stuff.

推荐答案

对于任何从 Google 搜索而来的人，我都想通了.事实证明，如果您希望能够动态地从水平变为垂直，反之亦然，则无法呈现自己的滚动组件.所以，如果我使用我之前的代码并注释掉对 renderScrollComponent 的调用，那么它就可以工作......就像这样:

For anyone coming in off of a Google search, I figured it out. Turns out you can't render your own scroll component if you want to be able to dynamically change from horizontal to vertical or vice versa. So, if I take my previous code and comment out the call to renderScrollComponent, then it works... like so:

<FlatList
    data={this.state.newsFeed}
    refreshing={this.state.refreshing}
    horizontal={this.state.isHorizontal}
    ref={ref => { this.newsFeedListRef = ref; }}
    renderItem={this.renderNewsFeedRow.bind(this)}
    keyExtractor={(item, index) => `feed_${index}`}
    onRefresh={this.__handleNewsFeedOnRefresh.bind(this)}
    //renderScrollComponent={this.renderScrollComponent.bind(this)}
    ListHeaderComponent={this.renderListHeaderComponent.bind(this)}
    getItemLayout={(data, index) => ({ index, length: ITEM_HEIGHT, offset: (ITEM_HEIGHT * index) })} />

我也可以像这样动态更新定位.我添加了一个函数级别 const 来计算我的项目大小，如下所示:

Also I can dynamically update the positioning like so. I add a function level const for calculating my item size like this:

const ITEM_SIZE = this.state.isHorizo​​ntal ?ITEM_HEIGHT : this.props.width;

然后我更新了我的 getItemLayout 函数，如下所示:

Then I updated my getItemLayout function to look like this:

getItemLayout={(data, index) =>({ index, length: ITEM_SIZE, offset: ITEM_SIZE * index })}/>

这篇关于React Native FlatList 水平模式根本不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！