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方位角测量示例

这个示例演示如何使用 DMap3D SDK 进行两点方位角测量。

效果预览​

用户点击两个点，自动计算从第一个点到第二个点的方位角（以正北为基准，顺时针方向 0°-360°），并显示北向指示箭头。

完整代码​

src/components/AzimuthMeasurement.tsx
import { useEffect, useRef, useState } from 'react'
import * as Cesium from 'cesium'
import DMap3D from 'dmap3d'
import './AzimuthMeasurement.css'

function AzimuthMeasurement() {
  const containerRef = useRef<HTMLDivElement>(null)
  const viewerRef = useRef<Cesium.Viewer | null>(null)
  const toolRef = useRef<any>(null)
  const [isActive, setIsActive] = useState(false)

  useEffect(() => {
    if (!containerRef.current) return

    Cesium.Ion.defaultAccessToken = 'your-cesium-ion-token'

    const viewer = new Cesium.Viewer(containerRef.current, {
      animation: false,
      fullscreenButton: false,
      geocoder: false,
      homeButton: false,
      sceneModePicker: false,
      selectionIndicator: false,
      timeline: false,
      navigationHelpButton: false,
      infoBox: false,
      baseLayerPicker: false,
      terrainProvider: new Cesium.EllipsoidTerrainProvider({}),
    })
    viewerRef.current = viewer

    viewer.camera.setView({
      destination: Cesium.Cartesian3.fromDegrees(116.4074, 39.9042, 5000),
      orientation: {
        heading: Cesium.Math.toRadians(0),
        pitch: Cesium.Math.toRadians(-45),
        roll: 0,
      },
    })

    // 创建方位角测量工具
    const tool = new DMap3D.measurement.azimuth(viewer)
    tool.updateConfig({
      pointColor: '#ff0000',
      lineColor: '#00ffff',
      fontColor: '#ffffff',
      fontSize: 16,
      arrowColor: '#ff0000',
      arrowLength: 50,
    })
    toolRef.current = tool

    return () => {
      tool.destroy()
      viewer.destroy()
    }
  }, [])

  const handleStart = () => {
    toolRef.current?.start()
    setIsActive(true)
  }

  const handleStop = () => {
    toolRef.current?.end()
    setIsActive(false)
  }

  const handleClear = () => {
    if (isActive) toolRef.current?.end()
    toolRef.current?.clear()
    setIsActive(false)
  }

  return (
    <div className="azimuth-measurement">
      <div ref={containerRef} className="cesium-container" />

      <div className="control-panel">
        <h3>方位角测量</h3>
        <p>点击两个点测量方位角</p>

        <div className="buttons">
          <button onClick={handleStart} disabled={isActive}>
            {isActive ? '测量中...' : '开始测量'}
          </button>
          <button onClick={handleStop} disabled={!isActive}>停止</button>
          <button onClick={handleClear}>清除</button>
        </div>

        <div className="compass">
          <h4>方位角参考</h4>
          <ul>
            <li><strong>0° / 360°</strong> - 正北</li>
            <li><strong>90°</strong> - 正东</li>
            <li><strong>180°</strong> - 正南</li>
            <li><strong>270°</strong> - 正西</li>
          </ul>
        </div>
      </div>
    </div>
  )
}

export default AzimuthMeasurement

样式文件​

src/components/AzimuthMeasurement.css
.azimuth-measurement {
  position: relative;
  width: 100%;
  height: 100vh;
}

.cesium-container { width: 100%; height: 100%; }

.control-panel {
  position: absolute; top: 20px; right: 20px;
  background: rgba(255, 255, 255, 0.95); padding: 20px;
  border-radius: 8px; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  min-width: 250px;
}

.control-panel h3 { margin: 0 0 10px 0; font-size: 18px; }
.control-panel p { margin: 0 0 15px 0; color: #666; font-size: 14px; }
.buttons { display: flex; gap: 8px; margin-bottom: 15px; }
.buttons button {
  flex: 1; padding: 8px 12px; border: none; border-radius: 4px;
  background: #1890ff; color: white; cursor: pointer; font-size: 14px;
}
.buttons button:hover { background: #40a9ff; }
.buttons button:disabled { background: #d9d9d9; cursor: not-allowed; }

.compass { border-top: 1px solid #e8e8e8; padding-top: 15px; }
.compass h4 { margin: 0 0 8px 0; font-size: 14px; color: #666; }
.compass ul { list-style: none; padding: 0; margin: 0; }
.compass li { font-size: 13px; margin: 4px 0; color: #666; }

关键代码说明​

1. 创建方位角测量工具​

const tool = new DMap3D.measurement.azimuth(viewer)
tool.updateConfig({
  arrowColor: '#ff0000',  // 北向指示箭头颜色
  arrowLength: 50,         // 箭头长度
})

2. 方位角说明​

方位角以正北方向为基准，顺时针旋转度量：

方位角方向
0°正北
45°东北
90°正东
135°东南
180°正南
225°西南
270°正西
315°西北

扩展功能​

  1. 磁偏角修正 - 考虑真北和磁北的偏差
  2. 反方位角 - 同时显示正反方位角
  3. 导航线 - 绘制方位角导航辅助线
  4. 坐标方位角 - 批量计算坐标串的方位角

相关 API​