连线地图 设置emphasis.label.position='middle'不起作用，还是用到默认的end echarts position':'middle配置项内容和展示

连线地图 设置emphasis.label.position='middle'不起作用，还是用到默认的end

      option = {
	"textStyle": {
		"color": "#fff"
	},
	"title": {
		"show": false,
		"text": "",
		"textStyle": {
			"color": "#fff"
		},
		"left": "center"
	},
	"tooltip": {
		"trigger": "item",
		"show": false
	},
	"toolbox": {
		"show": false,
		"orient": "vertical",
		"left": "right",
		"top": "center",
		"feature": {
			"dataView": {
				"readOnly": false
			},
			"restore": {},
			"saveAsImage": {}
		}
	},
	"backgroundColor": "rgba(0,0,0,0)",
	"geo": [{
		"map": "china",
		"roam": false,
		"label": {
			"normal": {
				"show": false,
				"textStyle": {
					"color": "#fff"
				}
			},
			"emphasis": {
				"show": false,
				"textStyle": {
					"color": "#fff"
				}
			}
		},
		"itemStyle": {
			"normal": {
				"areaColor": "rgba(0,0,0,0.1)",
				"borderColor": "rgba(0,0,0,0.5)",
				"borderWidth": 1
			},
			"emphasis": {
				"areaColor": "#81f214"
			}
		},
		"selectedMode": false
	}],
	"series": [{
		"type": "scatter",
		"coordinateSystem": "geo",
		"data": [{
			"name": "青岛a",
			"value": [120.33, 36.07],
			"itemStyle": {
				"color": "#ff0000"
			}
		}, {
			"name": "上海b",
			"value": [121.48, 31.22],
			"itemStyle": {
				"color": "#7FFF00"
			}
		}, {
			"name": "青岛",
			"value": [120.33, 36.07],
			"itemStyle": {
				"color": "#ff0000"
			}
		}, {
			"name": "上海",
			"value": [121.48, 31.22],
		}, {
			"name": "北京",
			"value": [116.46, 39.92],
			"symbolSize": 20
		}],
		"symbolSize": 13,
		"showEffectOn": "render",
		"rippleEffect": {
			"brushType": "stroke",
			"period": 1
		},
		"hoverAnimation": true,
		"label": {
			"normal": {
				"formatter": "{b}",
				"position": "right",
				"show": false,
				"color": "#fff"
			},
			"emphasis": {
				"show": true
			}
		},
		"itemStyle": {
			"normal": {
				"color": "#4ce741"
			},
			"emphasis": {
				"color": "#fafefd"
			}
		},
		"zlevel": 15
	}, {
		"type": "lines",
		"zlevel": 8,
		"symbolSize": 10,
		"lineStyle": {
			"normal": {
				"color": "#4ce741",
				"width": 2,
				"opacity": 0.6,
				"curveness": 0.2
			},
			"emphasis": {
				"width": 3
			}
		},
		"emphasis":{
            "label":{
            "show":true,
            'position':'middle',
            "color":'red'
            }
        },
		"data": [{
			"lineStyle": {
				"color": "#fc5e2d",
				"curveness": -0.8
			},
			"name": "青岛a - 上海b",
			"coords": [
				[120.33, 36.07],
				[121.48, 31.22]
			]
		}, {
			"lineStyle": {
				"color": "#fc5e2d",
				"curveness": 0.2
			},
			"name": "青岛 - 上海",
			"coords": [
				[120.33, 36.07],
				[121.48, 31.22]
			]
		}, {
			"lineStyle": {
				"color": "#fc5e2d",
				"curveness": 0.2
			},
			"name": "上海 - 北京",
			"coords": [
				[121.48, 31.22],
				[116.46, 39.92]
			]
		}]
	}, {
		"type": "lines",
		"zlevel": 9,
		"symbolSize": 10,
		"lineStyle": {
			"normal": {
				"color": "#a6c84c",
				"width": 0,
				"curveness": 0.2
			}
		},
		"emphasis":{
            "label":{
            "show":true,
            'position':'middle',
            "color":'red'
            }
        },
		"data": [{
			"lineStyle": {
				"color": "#fc5e2d",
				"curveness": -0.8
			},
			"name": "青岛1 - 上海2",
			"coords": [
				[120.33, 36.07],
				[121.48, 31.22]
			]
		}, {
			"lineStyle": {
				"color": "#fc5e2d",
				"curveness": 0.2
			},
			"name": "青岛 - 上海",
			"coords": [
				[120.33, 36.07],
				[121.48, 31.22]
			]
		}, {
			"lineStyle": {
				"color": "#fc5e2d",
				"curveness": 0.2
			},
			"name": "上海 - 北京",
			"coords": [
				[121.48, 31.22],
				[116.46, 39.92]
			]
		}],
		"effect": {
			"show": true,
			"period": 4,
			"trailLength": 0.3,
			"color": "#fff",
			"symbolSize": 2
		},
		"itemStyle": {
			"normal": {
				"color": "#4ce741"
			},
			"emphasis": {
				"color": "#fafefd"
			}
		}
	}],
	"animation": false
};