Question

我有一个问题，如何设置取决于当前速度的缩放级别？例如，当移动缓慢。缩放到近处，快速时，缩放到远处。

这是我的算法：

private int calculateZoomLevelBySpeed(float speed) {
    int zoomLevelMax = mapView.getMaxZoomLevel();
    // default
    int zoomLevel = (zoomLevelMax > 0) ? (int)zoomLevelMax / 2 : 4;

    if (speed > 0) {
        // 300km theoretically max / max zoom steps
        double step = 300 / zoomLevelMax;
        zoomLevel = (int) Math.round(speed / step);
        // reverse
        zoomLevel = zoomLevelMax - zoomLevel;
        zoomLevel = Math.min(zoomLevelMax,  zoomLevelMax);
        zoomLevel = Math.max(zoomLevelMax,  1);
    }
    return zoomLevel;
}

这不起作用，我该怎么做？

提前致谢。

Answer 1

试试这个，我没有真正测试它，但我希望它有所帮助

private int calculateZoomLevelBySpeed(float speed) 
{
    //assuming this line returns the max zoom level on maps
    int zoomLevelMax = mapView.getMaxZoomLevel(); 
    // default
    int zoomLevel = (zoomLevelMax > 0) ? (int)zoomLevelMax / 2 : 4;

    if (speed > 0) {
        // 300km theoretically max / max zoom steps
        double step = (speed / 300) * zoomLevelMax;
    }
    return Math.Round(zoomLevel);
}

Answer 2

试试这样：

private int calculateZoomLevelBySpeed(float speed) {
    int zoomLevelMax = mapView.getMaxZoomLevel();

    if (speed > 0) {
        // 300km theoretically max / max zoom steps
        double step = 300 / zoomLevelMax;
        zoomLevel = (int) Math.round(speed / step);
        // reverse
        zoomLevel = zoomLevelMax - zoomLevel;
    }
    return zoomLevel;
}

Android MapView动态设置缩放级别

2 个答案: