GeoCoordinateWatcher 只偶尔工作一次

Question

以下代码尝试获取代码所在计算机的位置运行：

GeoCoordinateWatcher watcher = new GeoCoordinateWatcher(GeoPositionAccuracy.High);
if (watcher.TryStart(false, TimeSpan.FromMilliseconds(3000)))
{
    GeoCoordinate coord = watcher.Position.Location;
    if (!coord.IsUnknown)
    {
        Printer.Print(String.Format("Current Lat: {0}, Current Long: {1}", coord.Latitude, coord.Longitude));
    }
    else // Path taken most often
    {
        throw new CommandException("Weather data unknown. (Are location services enabled?)"); 
    }
}
else
{
    throw new CommandException("Weather data unknown. (Are location services enabled?)");
}

每隔一段时间，打印正确的位置，但大多数时候，注释的else语句是运行。经过多次测试，我意识到它是否有效完全是随机的。我做错了吗？

Answer 1

您遇到问题的原因可能是您正在初始化一个新的定位器，但没有等待状态报告它已准备就绪，然后再检查位置。

bool abort = false;
GeoCoordinateWatcher watcher = new GeoCoordinateWatcher(GeoPositionAccuracy.High);
if (watcher.TryStart(false, TimeSpan.FromMilliseconds(3000)))
{
    DateTime start = DateTime.Now;
    while(watcher.Status != GeoPositionStatus.Ready && !abort)
    {
        Thread.Sleep(200);
        if(DateTime.Now.Subtract(start).TotalSeconds > 5)
            abort = true;
    }

    GeoCoordinate coord = watcher.Position.Location;
    if (!coord.IsUnknown)
    {
        Printer.Print(String.Format("Current Lat: {0}, Current Long: {1}", coord.Latitude, coord.Longitude));
    }
    else // Path taken most often
    {
        throw new CommandException("Weather data unknown. (Are location services enabled?)"); 
    }
}
else
{
    throw new CommandException("Weather data unknown. (Are location services enabled?)");
}

基本上这会添加一个检查以查看状态是否就绪并最多等待 5 秒。

或者，观察者通常应在模块级别设置并注册 PositionChanged 事件，以便您仅在位置实际更改时更新打印输出，而不是重复的轮询循环静止时反复移动当前位置。

GeoCoordinateWatcher 只偶尔工作一次

GeoCoordinateWatcher only works once in a while

c#

wpf

location