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基于Uni-app+vue3实现微信小程序地图固定中心点范围内拖拽选择位置功能（分步骤详解）

news 2025/8/17 9:21:35

一、功能概述与实现步骤

1.1 功能需求

显示地图并固定中心点标记
绘制服务区域多边形边界
实时检测拖拽后位置是否在服务区内
提供位置确认和超出范围提示功能

1.2 实现步骤分解

第一步：初始化地图基础配置

创建Map组件并设置基本属性
定义服务区域多边形坐标
设置地图初始中心点

第二步：实现地图交互逻辑

监听地图拖拽事件
获取拖拽后中心点坐标
判断坐标是否在服务区内

第三步：实现覆盖层UI

固定中心点标记
位置信息显示面板

操作按钮（确认/返回服务区）

二、分步骤代码实现

2.1 第一步：地图基础配置

<template><view class="map-container"><mapid="map"style="width: 100%; height: 80vh":latitude="center.latitude":longitude="center.longitude":polygons="polygons"@regionchange="handleMapDrag":show-location="true"><!-- 覆盖层将在第三步添加 --></map></view>
</template><script setup>
import { ref, onMounted } from "vue";// 服务区域边界坐标
const serviceAreaPolygon = [{ latitude: 34.808, longitude: 113.55 },{ latitude: 34.805, longitude: 113.58 },// ...其他坐标点{ latitude: 34.808, longitude: 113.55 } // 闭合多边形
];// 中心点位置
const center = ref({latitude: 34.747, longitude: 113.625
});// 多边形配置
const polygons = ref([{points: serviceAreaPolygon,strokeWidth: 2,strokeColor: "#1E90FF",fillColor: "#1E90FF22"
}]);// 初始化地图上下文
const mapContext = ref(null);
onMounted(() => {mapContext.value = uni.createMapContext("map");
});
</script>

2.2 第二步：地图交互逻辑实现

// 当前坐标点
const currentPos = ref({ ...center.value });
// 是否在服务区内
const isInServiceArea = ref(true);// 地图拖拽事件处理
const handleMapDrag = (e) => {if (e.type === "end") {mapContext.value.getCenterLocation({success: (res) => {currentPos.value = {latitude: res.latitude,longitude: res.longitude};// 判断是否在服务区内isInServiceArea.value = isPointInPolygon(currentPos.value,serviceAreaPolygon);}});}
};// 射线法判断点是否在多边形内
function isPointInPolygon(point, polygon) {const { latitude, longitude } = point;let inside = false;for (let i = 0, j = polygon.length - 1; i < polygon.length; j = i++) {const xi = polygon[i].longitude, yi = polygon[i].latitude;const xj = polygon[j].longitude, yj = polygon[j].latitude;const intersect = ((yi > latitude) !== (yj > latitude))&& (longitude < (xj - xi) * (latitude - yi) / (yj - yi) + xi);if (intersect) inside = !inside;}return inside;
}

2.3 第三步：覆盖层UI实现

<!-- 在map标签内添加 -->
<cover-view class="center-marker"></cover-view><cover-view class="info-box" :class="{ 'out-of-range': !isInServiceArea }"><cover-view v-if="isInServiceArea">当前位置在服务区域内</cover-view><cover-view v-else class="error">当前选择位置超出服务区域</cover-view><cover-view class="coords">纬度: {{ currentPos.latitude.toFixed(6) }} 经度: {{ currentPos.longitude.toFixed(6) }}</cover-view><cover-view v-if="!isInServiceArea" class="recenter-btn" @tap="centerToServiceArea">查看最近的服务区域</cover-view><cover-view v-else class="confirm-btn" @tap="confirmLocation">确定上车位置</cover-view>
</cover-view>

2.4 第四步：业务功能完善

// 返回服务区中心
const centerToServiceArea = () => {const center = getPolygonCenter(serviceAreaPolygon);currentPos.value = { ...center };isInServiceArea.value = true;mapContext.value.moveToLocation({latitude: center.latitude,longitude: center.longitude});
};// 计算多边形中心点
function getPolygonCenter(polygon) {let latSum = 0, lngSum = 0;polygon.forEach(point => {latSum += point.latitude;lngSum += point.longitude;});return {latitude: latSum / polygon.length,longitude: lngSum / polygon.length};
}// 确认位置
const confirmLocation = () => {uni.showToast({title: `位置已确认: ${currentPos.value.latitude.toFixed(6)}, ${currentPos.value.longitude.toFixed(6)}`,icon: "none"});// 实际业务中可以触发回调或跳转
};

三、完整实现代码

<template><view class="map-container"><mapid="map"style="width: 100%; height: 80vh":latitude="center.latitude":longitude="center.longitude":polygons="polygons"@regionchange="handleMapDrag":show-location="true"><cover-view class="center-marker"></cover-view><cover-view class="info-box" :class="{ 'out-of-range': !isInServiceArea }"><cover-view v-if="isInServiceArea">当前位置在服务区域内</cover-view><cover-view v-else class="error">当前选择位置超出服务区域</cover-view><cover-view class="coords">纬度: {{ currentPos.latitude.toFixed(6) }} 经度: {{ currentPos.longitude.toFixed(6) }}</cover-view><cover-view v-if="!isInServiceArea" class="recenter-btn" @tap="centerToServiceArea">查看最近的服务区域</cover-view><cover-view v-else class="confirm-btn" @tap="confirmLocation">确定上车位置</cover-view></cover-view></map></view>
</template><script setup>
import { ref, onMounted } from "vue";// 服务区域边界
const serviceAreaPolygon = [{ latitude: 34.808, longitude: 113.55 },{ latitude: 34.805, longitude: 113.58 },{ latitude: 34.79, longitude: 113.61 },{ latitude: 34.765, longitude: 113.625 },{ latitude: 34.735, longitude: 113.62 },{ latitude: 34.71, longitude: 113.6 },{ latitude: 34.7, longitude: 113.57 },{ latitude: 34.715, longitude: 113.54 },{ latitude: 34.75, longitude: 113.53 },{ latitude: 34.808, longitude: 113.55 }
];const center = ref(getPolygonCenter(serviceAreaPolygon));
const currentPos = ref({ ...center.value });
const isInServiceArea = ref(true);
const mapContext = ref(null);const polygons = ref([{points: serviceAreaPolygon,strokeWidth: 2,strokeColor: "#1E90FF",fillColor: "#1E90FF22"
}]);onMounted(() => {mapContext.value = uni.createMapContext("map");
});const handleMapDrag = (e) => {if (e.type === "end") {mapContext.value.getCenterLocation({success: (res) => {currentPos.value = {latitude: res.latitude,longitude: res.longitude};isInServiceArea.value = isPointInPolygon(currentPos.value,serviceAreaPolygon);}});}
};function isPointInPolygon(point, polygon) {const { latitude, longitude } = point;let inside = false;for (let i = 0, j = polygon.length - 1; i < polygon.length; j = i++) {const xi = polygon[i].longitude, yi = polygon[i].latitude;const xj = polygon[j].longitude, yj = polygon[j].latitude;const intersect = ((yi > latitude) !== (yj > latitude))&& (longitude < (xj - xi) * (latitude - yi) / (yj - yi) + xi);if (intersect) inside = !inside;}return inside;
}function getPolygonCenter(polygon) {let latSum = 0, lngSum = 0;polygon.forEach(point => {latSum += point.latitude;lngSum += point.longitude;});return {latitude: latSum / polygon.length,longitude: lngSum / polygon.length};
}const centerToServiceArea = () => {const center = getPolygonCenter(serviceAreaPolygon);currentPos.value = { ...center };isInServiceArea.value = true;mapContext.value.moveToLocation({latitude: center.latitude,longitude: center.longitude});
};const confirmLocation = () => {uni.showToast({title: `位置已确认: ${currentPos.value.latitude.toFixed(6)}, ${currentPos.value.longitude.toFixed(6)}`,icon: "none"});
};
</script><style scoped>
.map-container {width: 100%;height: 100vh;position: relative;
}.center-marker {position: absolute;top: 50%;left: 50%;transform: translate(-50%, -50%);width: 20px;height: 20px;background-color: #5ca7fc;border-radius: 50%;border: 2px solid white;z-index: 999;
}.info-box {position: absolute;top: 20%;left: 50%;transform: translateX(-50%);background: rgba(255, 255, 255, 0.9);padding: 12px 16px;border-radius: 8px;width: 80%;box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}.info-box.out-of-range {background: rgba(255, 240, 240, 0.9);
}.coords {font-size: 12px;color: #666;margin: 8px 0;
}.error {color: #f56c6c;font-weight: bold;
}.recenter-btn, .confirm-btn {margin-top: 10px;padding: 8px 12px;border-radius: 4px;text-align: center;font-size: 14px;
}.recenter-btn {background: #606266;color: white;
}.confirm-btn {background: #409eff;color: white;
}
</style>