Flex布局【实战】

实战：使用 Flex 布局构建如下界面

分析：

1. 竖向：使用 flex 布局将页面分为三部分，即头部、主体和底部。其中头部和底部需要固定高度，其余的高度分配给主体部分（使用 flex-direction=column; 和 flex-grow: 1;）
2. 主体部分：使用 flex 布局排列多个卡片，这里可以使用 uniapp 提供的 scroll-view 滚动视图
3. 底部：使用 flex 布局多个视图

一种实现：

<template>
	<view class="main-page">
		<view class="head-part">
			Coursa Is All your Need!
		</view>
		<view class="body-part">
			<scroll-view scroll-y="true" class="scroll-view-clz">
				<view class="list-scroll-views">
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
					<view class="view-item">
						<image src="../../static/course.png" mode="widthFix"></image>
						<view>uniapp实战</view>
						<view>免费</view>
					</view>
				</view>
			</scroll-view>
		</view>
		<view class="bottom-part">
			<view class="bottom-item">
				<image src="@/static/tools/add.png" mode="widthFix"></image>
				<view class="des">添加</view>
			</view>
			<view class="bottom-item">
				<image src="@/static/tools/done.png" mode="widthFix"></image>
				<view class="des">完成</view>
			</view>
			<view class="bottom-item">
				<image src="@/static/tools/store.png" mode="widthFix"></image>
				<view class="des">商店</view>
			</view>
			<view class="bottom-item">
				<image src="@/static/tools/message.png" mode="widthFix"></image>
				<view class="des">消息</view>
			</view>
		</view>
	</view>
</template>

<script>
</script>

<style>
	.main-page {
		width: 100%;
		height: 100vh;
		display: flex;
		flex-direction: column;
	}

	.head-part {
		height: 5vh;
		line-height: 5vh;
		font-size: 30px;
		text-align: center;
		background-color: #f8f8f8;
	}

	.body-part {
		height: 100%;
		margin: 10px 0;
		background-color: #f8f8f8;
		flex-grow: 1;
		position: relative;
	}

	.scroll-view-clz {
		position: absolute;
		top: 0;
		left: 0;
		bottom: 0;
		right: 0;
	}

	.list-scroll-views {
		width: 100%;
		display: flex;
		flex-wrap: wrap;
		justify-content: space-around;
	}

	.view-item {
		width: 43vw;
		margin-top: 10px;
		margin-bottom: 10px;
	}

	.view-item image {
		width: 100%;
		border-radius: 10px;
	}

	.bottom-part {
		width: 100%;
		background-color: #f8f8f8;
		display: flex;
		flex-wrap: wrap;
		justify-content: space-around;
	}

	.bottom-item {
		width: 45px;
		font-size: 14px;
		text-align: center;
		padding: 10px 0;
	}

	.bottom-item image {
		width: 100%;
	}
</style>

其中的主体定位中的元素采用了绝对定位。

• 绝对定位：An element with position: absolute; is positioned relative to the nearest positioned ancestor (instead of positioned relative to the viewport, like fixed)
• 绝对定位示例：https://www.w3schools.com/css/tryit.asp?filename=trycss_position_absolute