el-checkbox-group全选、单选实现

页面结构：

<el-checkbox-group v-model="checkedCities" @change="handleCheckedCitiesChange">
					<el-checkbox v-for="(city,i) in cities" :label="city.path" :key="i">{{city.time}}</el-checkbox>
</el-checkbox-group>
<el-checkbox size="small" :indeterminate="isIndeterminate" v-model="checkAll" @change="handleCheckAllChange">全选</el-checkbox>

js方法：

checkAll: true,
cities: [], //数据源
checkedCities:[], //绑定默认选中
isIndeterminate:false, //设置 indeterminate 状态，只负责样式控制

handleCheckedCitiesChange(value) {//单选
				let _self=this; 				
				var modelBounds = new qq.maps.LatLngBounds(
					new qq.maps.LatLng(_self.park.latMax,_self.park.lngMin),
					new qq.maps.LatLng(_self.park.latMin,_self.park.lngMax)
				);  	
				nperArray=common.bSort(value);//冒泡排序	
				for(let i=0;i< nperArray.length;i++){                                   
					this.mtOlayArray[i] = new qq.maps.GroundOverlay({
						map:_self.map,
						imageUrl:_self.global.apiUrl + nperArray[i]+'?t=' + Math.random(),            
						bounds: modelBounds,
						visible:true,
						opacity: 0.4,
						zIndex: 3
					});                     
				}
			},
			handleCheckAllChange(val) { //全选
			            let _self=this;  
			            this.checkedCities=[];						
			            this.cities.forEach(item=>{  
			                this.checkedCities.push(item.path)
			            })  
			            if(val){       
			                var modelBounds = new qq.maps.LatLngBounds(
			                    new qq.maps.LatLng(_self.parkCenter.lngMin,_self.parkCenter.latMax),
			                    new qq.maps.LatLng(_self.parkCenter.lngMax,_self.parkCenter.latMin)
			                );
			               
			                for(let i=0;i< this.checkedCities.length;i++){                                   
			                    this.mtOlayArray[i] = new qq.maps.GroundOverlay({
			                        map:_self.map,
			                        imageUrl:_self.global.apiUrl + this.checkedCities[i]+'?t=' + Math.random(),            
			                        bounds: modelBounds,
			                        visible:true,
			                        opacity: 0.4,
			                        zIndex: 3
			                    });                     
			                }  
			            }
			            this.checkedCities = val ? this.checkedCities : []; 
			            this.isIndeterminate = false;  
			      },