/// <summary>
/// 仅在第一次初始化时执行
/// </summary>
public async void OnFirstLoad()
{
Geoposition Position;
try
{
Position = await GetPositionAsync();
}
catch (InvalidOperationException)
{
WeatherCtr.Error(ErrorReason.Location);
return;
}
catch (Exception)
{
WeatherCtr.Error(ErrorReason.NetWork);
return;
}
//将获取到的GPS位置发送至百度地图逆地址解析服务
float lat = (float)Position.Coordinate.Point.Position.Latitude;
float lon = (float)Position.Coordinate.Point.Position.Longitude;
string URL = "http://api.map.baidu.com/reverse_geocoding/v3/?ak=qrTMQKoNdBj3H6N7ZTdIbRnbBOQjcDGQ&output=json&coordtype=wgs84ll&location=" + lat + "," + lon;
string Result = await GetWebResponseAsync(URL);
if (Result != "")
{
//异步运行以在完成诸多解析任务的同时保持UI响应能力
await Task.Run(async() =>
{
var WeatherInfo = await GetWeatherInfoAsync(GetDistrictByAnalysisJSON(Result));
if (WeatherInfo == null)
{
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
WeatherCtr.Error(ErrorReason.APIError);
});
return;
}
//status=200时表示请求成功
if (WeatherInfo.status == 200)
{
WeatherDataGenarated?.Invoke(null, new WeatherData(WeatherInfo.data, jp.result.addressComponent.city + jp.result.addressComponent.district));
}
else
{
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
WeatherCtr.Error(ErrorReason.APIError);
});
}
});
}
}
/// <summary>
/// 向URL指定的网络服务器发出HTTP请求，获取返回服务器返回信息
/// </summary>
/// <param name="url">网络服务器地址</param>
/// <returns>网络服务器返回的信息</returns>
private async Task <string> GetWebResponseAsync(string url)
{
string strBuff = string.Empty;
Uri HttpURL = new Uri(url);
WebRequest httpReq = WebRequest.Create(HttpURL);
try
{
WebResponse httpResp = await httpReq.GetResponseAsync();
Stream respStream = httpResp.GetResponseStream();
StreamReader respStreamReader = new StreamReader(respStream, Encoding.UTF8);
strBuff = await respStreamReader.ReadToEndAsync();
}
catch (WebException)
{
WeatherCtr.Error(ErrorReason.NetWork);
}
return(strBuff);
}