iOS超声检测（17khz-22 kHz，采样率44.1khz）
detect Ultra sound和Show Alert Detecting
Ultra sound ultrasound
(17khz-22 kHz) 范围为sampling rate，44.1Khz为detect show alert如何ultraSound和ios Objective c <Window x:Class="WPFTestApplication.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:m="clr-namespace:Microsoft.Maps.MapControl.WPF;assembly=Microsoft.Maps.MapControl.WPF"
Width="1024" Height="768">
<Grid x:Name="LayoutRoot" Background="White">
<m:Map x:Name="myMap" CredentialsProvider="Insert_Your_Bing_Maps_Key" Center="47.740,-122.125" ZoomLevel="11">
<m:MapPolyline Stroke="Blue" StrokeThickness="5"
Locations="47.6424,-122.3219 47.8424,-122.1747 47.5814,-122.1747 47.67856,-122.130994"
Opacity="0.7"/>
</m:Map>
</Grid>
</Window>
{/ 1}}