ArcGIS for Android地图上实际距离与对应的屏幕像素值计算

    /**
     * 将实际地理距离转换为屏幕像素值
     * 
     * @param distance
     *            实际距离,单位为米
     * @param currScale
     *            当前地图尺寸
     * @param context
     * @return
     */
    public static double metreToScreenPixel(double distance, double currScale,
            Context context) {
        float dpi = context.getResources().getDisplayMetrics().densityDpi;
        // 当前地图范围内1像素代表多少地图单位的实际距离
        double resolution = (25.39999918 / dpi)
                * currScale / 1000;
        return distance / resolution;
    }

    /**
     * 将屏幕上对应的像素距离转换为当前显示地图上的地理距离(米)
     * 
     * @param pxlength
     * @param currScale
     * @param context
     * @return
     */
    public static double screenPixelToMetre(double pxlength, double currScale,
            Context context) {
        float dpi = context.getResources().getDisplayMetrics().densityDpi;
        double resolution = (25.39999918 / dpi)
                * currScale / 1000;
        return pxlength * resolution;
    }

来自：http://blog.csdn.net/u012481275/article/details/12861179