效果

 代码

 

<template>
	<view>
		<view class='line3'>
			<view class='line3_position'>
				<view class='left'>数量<text>*</text></view> 
				<view class="right">
						<view class="quantity_btn">
							<view class="minus_quantity" @click="decrease">-</view>
							<input class="input_quantity" type="number" v-model="quantity" @input="handleInput">
							<view class="add_quantity" @click="increase">+</view>
						</view>
				</view>
			</view>
		</view>

	</view>
</template>

<script>
	export default {
		data() {
			return {
				quantity: 1
			};
		},
		methods: {
			handleInput(event) {
				const value = parseInt(event.target.value);
				if (!isNaN(value) && value >= 1) {
					this.quantity = value;
				} else {
					this.quantity = 1;
				}
			},
			increase() {
				this.quantity++;
			},
			decrease() {
				if (this.quantity > 1) {
					this.quantity--;
				}
			}
		}
	};
</script>
<style lang="scss">
	.quantity_btn {
		display: flex;
		width: 50%;

		.add_quantity {
			border: 1px solid #74bfe7;
			text-align: center;
			width: 25%;
		}

		.input_quantity {
			// border-bottom: 1px solid #74bfe7;
			text-align: center;
			width: 50%;
		}

		.minus_quantity {
			border: 1px solid #74bfe7;
			text-align: center;
			width: 25%;
		}

	}

	.line3 {
		padding: 20rpx;
		// border: 1px solid black;
		.line3_position{
			width: 100%;
			display: flex;
			.left {
				width: 30%;
				// border: 1px solid black;
			}
			.right {
				display:flex;
				justify-content:flex-end;
				width: 70%;
				// border: 1px solid black;
			}
		}
		// border:1px solid black;
		
	}
</style>