Windows Phone 十八、罗盘

1     <Grid Background="White">
2         <Image Source="compass.png" RenderTransformOrigin="0.5,0.5">
3             <Image.RenderTransform>
4                 <CompositeTransform x:Name="rotate" Rotation="1"/>
5             </Image.RenderTransform>
6         </Image>
7     </Grid>

 1         protected override void OnNavigatedTo(NavigationEventArgs e)
 2         {
 3             Compass c = Compass.GetDefault();
 4             if (c == null)
 5             {
 6                 // 不支持罗盘
 7                 return;
 8             }
 9             c.ReadingChanged += async (p1, p2) =>
10             {
11                 // 修改图片的旋转角度；
12                 System.Diagnostics.Debug.WriteLine(p2.Reading.HeadingTrueNorth.Value);
13                 await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
14                 {
15                     rotate.Rotation = -p2.Reading.HeadingTrueNorth.Value;
16                 });
17             };
18             c.ReportInterval = c.MinimumReportInterval * 10;
19         }