渲染异步创建的自定义引脚Xamarin.Forms的问题 Download


我对customrender有问题，因为我异步创建了地图图钉（下面的代码），但是要自定义图钉和信息窗口，我需要同步获取这些图钉的列表，我是新手，请谅解并提供帮助这个问题。谢谢

private async void MapPins()

    {
        var locator = CrossGeolocator.Current;
        locator.DesiredAccuracy = 50;
        var position = await locator.GetPositionAsync();

        var allPins = await firebaseHelper.GetAllparameters();



        foreach (Pin item in allPins)
        {
            var dys = Location.CalculateDistance(new Location(position.Latitude, position.Longitude), new Location(Convert.ToDouble(item.Latitude), Convert.ToDouble(item.Longitude)), DistanceUnits.Kilometers);
            if (dys < 0.3)
            {
                CustomPin pin = new CustomPin
                {
                    Type = PinType.Place,
                    Position = new Position(Convert.ToDouble(item.Latitude), Convert.ToDouble(item.Longitude)),
                    Label = item.Name,
                    Address = item.Adress,
                    Name = item.Name,

                };

                customMap.Pins.Add(pin);                  
            }

        }

    }

1 个答案:

答案 0 :(得分：0)

首先应创建所有引脚，创建完成后，即可开始自定义引脚和信息窗口。

private async void MapPins()

{
    var locator = CrossGeolocator.Current;
    locator.DesiredAccuracy = 50;
    var position = await locator.GetPositionAsync();

    var allPins = await firebaseHelper.GetAllparameters();



    foreach (Pin item in allPins)
    {
        var dys = Location.CalculateDistance(new Location(position.Latitude, position.Longitude), new Location(Convert.ToDouble(item.Latitude), Convert.ToDouble(item.Longitude)), DistanceUnits.Kilometers);
        if (dys < 0.3)
        {
            CustomPin pin = new CustomPin
            {
                Type = PinType.Place,
                Position = new Position(Convert.ToDouble(item.Latitude), Convert.ToDouble(item.Longitude)),
                Label = item.Name,
                Address = item.Adress,
                Name = item.Name,

            };

            customMap.Pins.Add(pin);
        }

    }

    // customize the pins and the information window here 
    // get all pins
    List<CustomPin> pins = customMap.Pins;
    //add your customize code
}



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