Windows phone 8 学习笔记(7) 设备

本节主要涉及到 Windows phone 8 手机支持的各类设备,包括相机、设备状态,振动装置等。还有各类感应器,包括磁力计、加速度器和陀螺仪。通过设备状态可以获取内存、硬件、电源、键盘等状态;通过相机捕获照片和视频;各类感应器帮助我们获取设备的运动状态等。

快速导航:
    一、设备状态
    二、相机
    三、罗盘传感器
    四、加速度计
    五、陀螺仪
    六、如何振动手机

一、设备状态

通过DeviceStatus 类我们可以确定设备的相关状态信息,比如内存大小啊,固件版本啊,还有是否部署了物理键盘等信息,以及与电源的相关信息,当前是电池还是外部电源等。

我们通过下面的代码展示如何获取这些信息。

 [C#]
        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)

        {



           var timer = new DispatcherTimer();

            timer.Interval = new TimeSpan(0, 0, 10);

            timer.Tick += new EventHandler((a, b) =>

            {



                //当前内存使用了多少字节

                var x = Microsoft.Phone.Info.DeviceStatus.ApplicationCurrentMemoryUsage;

                textblock1.Text = "当前内存:" + convert(x);



                //高峰时内存使用了多少字节

                var y = Microsoft.Phone.Info.DeviceStatus.ApplicationPeakMemoryUsage;

                textblock2.Text = "峰值内存:" + convert(y);



            });

            timer.Start();





            textblock3.Text = "设备制造商名:"+ DeviceStatus.DeviceManufacturer;

            textblock4.Text = "设备名:" + DeviceStatus.DeviceName;

            textblock5.Text = "固件版本:"+ DeviceStatus.DeviceFirmwareVersion;

            textblock6.Text = "硬件版本:"+ DeviceStatus.DeviceHardwareVersion;

            textblock7.Text = "物理内存大小:"+convert( DeviceStatus.DeviceTotalMemory);

            textblock8.Text = "应用进程可分配最大额外内存:" + convert(DeviceStatus.ApplicationMemoryUsageLimit);

            textblock9.Text ="是否包含硬件键盘:"+ DeviceStatus.IsKeyboardPresent.ToString();

            textblock10.Text = "是否部署硬件键盘:" + DeviceStatus.IsKeyboardDeployed.ToString();

            textblock11.Text = "电源状态:" + DeviceStatus.PowerSource.ToString();



            //关闭或部署键盘时

            DeviceStatus.KeyboardDeployedChanged += new EventHandler((a, b) => {

                textblock9.Text = "键盘变更,是否包含硬件键盘:" + DeviceStatus.IsKeyboardPresent.ToString();

            });





            //设备电源变更时

            DeviceStatus.PowerSourceChanged += new EventHandler((a, b) =>

            {

                textblock11.Text = "电源状态变更:" + DeviceStatus.PowerSource.ToString();

            });



            base.OnNavigatedTo(e);

        }



        private string convert(long x)

        {

            return Math.Round(x / (1024.0 * 1024.0), 2) + "M";

        }

 Windows phone 8 学习笔记(7) 设备

二、相机

有两个类可以调用相机,分别是PhotoCamera和PhotoCaptureDevice,一般如果要支持WP7以及对相机基本调用则使用前者,后者用于相机的高级捕获。

1.PhotoCamera

我们首先通过PhotoCamera来访问相机,我们可以实现一个具备拍照功能的基本相机,包含自动对焦、闪光灯、分辨率调整等功能,下面代码演示了如何使用。

[XAML]
    <Grid x:Name="LayoutRoot" Background="Transparent">

        <Canvas x:Name="canvas1" Margin="0,0,0,0" Tap="canvas1_Tap" Width="800" Height="480">

            <Canvas.Background>

                <VideoBrush x:Name="viewfinderBrush" />

            </Canvas.Background>

            <TextBlock x:Name="focusBrackets" Text="[   ]" FontSize="40" Visibility="Collapsed"/>

        </Canvas>



        <ListBox x:Name="listbox1" Margin="95,394,538,59" SelectionChanged="listbox1_SelectionChanged">

            <ListBox.ItemTemplate>

                <DataTemplate>

                    <TextBlock Text="{Binding}"></TextBlock>

                </DataTemplate>

            </ListBox.ItemTemplate>

            <ListBox.ItemContainerStyle>

                <Style TargetType="ListBoxItem">

                    <Setter Property="Margin" Value="0,0,10,0" />

                </Style>

            </ListBox.ItemContainerStyle>

            <ListBox.ItemsPanel>

                <ItemsPanelTemplate>

                    <StackPanel Orientation="Horizontal"></StackPanel>

                </ItemsPanelTemplate>

            </ListBox.ItemsPanel>

        </ListBox>

        <TextBlock x:Name="textblock1" Foreground="Red" HorizontalAlignment="Left" Margin="584,22,0,0" TextWrapping="Wrap" VerticalAlignment="Top"/>

        <TextBlock HorizontalAlignment="Left" Margin="10,394,0,0" TextWrapping="Wrap" Text="闪光灯:" VerticalAlignment="Top"/>

        <TextBlock HorizontalAlignment="Left" Margin="273,394,0,0" TextWrapping="Wrap" Text="分辨率:" VerticalAlignment="Top"/>

        <ListBox x:Name="listbox2" Margin="350,394,10,59" SelectionChanged="listbox2_SelectionChanged">

            <ListBox.ItemTemplate>

                <DataTemplate>

                    <TextBlock Text="{Binding}"/>

                </DataTemplate>

            </ListBox.ItemTemplate>

            <ListBox.ItemContainerStyle>

                <Style TargetType="ListBoxItem">

                    <Setter Property="Margin" Value="0,0,10,0" />

                </Style>

            </ListBox.ItemContainerStyle>

            <ListBox.ItemsPanel>

                <ItemsPanelTemplate>

                    <StackPanel Orientation="Horizontal"/>

                </ItemsPanelTemplate>

            </ListBox.ItemsPanel>

        </ListBox>

        <Button Content="对焦" HorizontalAlignment="Left" Margin="517,410,0,0" VerticalAlignment="Top" Click="Button_Click_1"/>

        <Button Content="拍照" HorizontalAlignment="Left" Margin="623,410,0,0" VerticalAlignment="Top" Click="Button_Click_2"/>

        <TextBlock Width="500" x:Name="textblock2" HorizontalAlignment="Left" Margin="10,434,0,0" TextWrapping="Wrap" VerticalAlignment="Top"/>

    </Grid>

[C#] 
    public partial class MainPage : PhoneApplicationPage

    {

        // 构造函数

        public MainPage()

        {

            InitializeComponent();

        }



        PhotoCamera photoCamera;

        MediaLibrary library = new MediaLibrary();



        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)

        {

            //判断是否支持相机

            if (PhotoCamera.IsCameraTypeSupported(CameraType.Primary))

            {

                textblock1.Text = "当前取景:后置摄像头";

                photoCamera = new PhotoCamera(CameraType.Primary);

            }

            else if (PhotoCamera.IsCameraTypeSupported(CameraType.FrontFacing))

            {

                textblock1.Text = "当前取景:前置摄像头";

                photoCamera = new PhotoCamera(CameraType.FrontFacing);

            }

            else

            {

                textblock1.Text = "设备不支持相机";

                return;

            }

            textblock2.Text = "相机正在初始化中.";

            viewfinderBrush.SetSource(photoCamera);

            //相机初始化完成时

            photoCamera.Initialized += (a, b) =>

            {

                if (b.Succeeded)

                {

                    this.Dispatcher.BeginInvoke(() =>

                    {

                        SupportedFlashModesInit();

                        AvailableResolutionsInit();

                        textblock2.Text = "相机初始化完成.";

                    });

                }

            };



            //有图像可用时(拍摄完成)

            photoCamera.CaptureImageAvailable += (a, b) =>

            {

                this.Dispatcher.BeginInvoke(() => { textblock2.Text = "正在保存照片."; });

                library.SavePictureToCameraRoll(Guid.NewGuid().ToString() + ".jpg", b.ImageStream);

                this.Dispatcher.BeginInvoke(() => { textblock2.Text = "照片保存成功."; });

            };



            //对焦完成时

            photoCamera.AutoFocusCompleted += (a, b) =>

            {

                this.Dispatcher.BeginInvoke(() =>

                {

                    textblock2.Text = "自动对焦完成.";

                    focusBrackets.Visibility = Visibility.Collapsed;

                });

            };



            base.OnNavigatedTo(e);

        }



        /// <summary>

        /// 显示支持的闪光模式

        /// </summary>

        private void SupportedFlashModesInit()

        {

            List<string> flashModes = new List<string>() { "关" };

            if (photoCamera.IsFlashModeSupported(FlashMode.On)) flashModes.Add("开");

            if (photoCamera.IsFlashModeSupported(FlashMode.Auto)) flashModes.Add("自动");

            if (photoCamera.IsFlashModeSupported(FlashMode.RedEyeReduction)) flashModes.Add("红眼");

            listbox1.ItemsSource = flashModes;

        }



        /// <summary>

        /// 显示支持的分辨率

        /// </summary>

        private void AvailableResolutionsInit()

        {

            listbox2.ItemsSource = photoCamera.AvailableResolutions;

        }



        //对焦

        private void Button_Click_1(object sender, RoutedEventArgs e)

        {

            //是否支持自动对焦

            if (photoCamera.IsFocusSupported == true)

            {

                try

                {

                    photoCamera.Focus();

                }

                catch(Exception ex)

                {

                    this.Dispatcher.BeginInvoke(() => { textblock2.Text = "对焦错误:" + ex.Message; });

                }

            }

            else

            {

                this.Dispatcher.BeginInvoke(() => { textblock2.Text = "相机不支持自动对焦."; });

            }

        }



        //拍照

        private void Button_Click_2(object sender, RoutedEventArgs e)

        {

            if (photoCamera != null)

            {

                try

                {

                    photoCamera.CaptureImage();

                }

                catch (Exception ex)

                {

                    this.Dispatcher.BeginInvoke(() => { textblock2.Text = "拍照错误:" + ex.Message; });

                }

            }

        }



        //特定点对焦

        private void canvas1_Tap(object sender, GestureEventArgs e)

        {

            if (photoCamera == null) return;

            if (!photoCamera.IsFocusAtPointSupported)

            {



                textblock2.Text = "不支持特定点对焦";

                return;

            }



            try

            {

                Point tapLocation = e.GetPosition(canvas1);



                focusBrackets.SetValue(Canvas.LeftProperty, tapLocation.X - 30);

                focusBrackets.SetValue(Canvas.TopProperty, tapLocation.Y - 28);



                double focusXPercentage = tapLocation.X / canvas1.Width;

                double focusYPercentage = tapLocation.Y / canvas1.Height;



                focusBrackets.Visibility = Visibility.Visible;

                photoCamera.FocusAtPoint(focusXPercentage, focusYPercentage);



                this.Dispatcher.BeginInvoke(delegate()

                {

                    textblock2.Text = String.Format("针对位置 [{0:N2} , {1:N2}] 开始对焦", focusXPercentage, focusYPercentage);

                });

            }

            catch (Exception focusError)

            {



                this.Dispatcher.BeginInvoke(delegate()

                {

                    textblock2.Text ="对焦错误:"+ focusError.Message;

                    focusBrackets.Visibility = Visibility.Collapsed;

                });

            }



        }



        //切换闪光灯模式

        private void listbox1_SelectionChanged(object sender, SelectionChangedEventArgs e)

        {

            if (e.AddedItems.Count == 0) return;

            switch (e.AddedItems[0].ToString())

            {

                case "关":

                    photoCamera.FlashMode = FlashMode.Off;

                    break;

                case "自动":

                    photoCamera.FlashMode = FlashMode.Auto;

                    break;

                case "红眼":

                    photoCamera.FlashMode = FlashMode.RedEyeReduction;

                    break;

                case "开":

                    photoCamera.FlashMode = FlashMode.On;

                    break;

            }

            textblock2.Text = "已将闪光模式设置为:" + e.AddedItems[0].ToString();

        }

        //切换分辨率

        private void listbox2_SelectionChanged(object sender, SelectionChangedEventArgs e)

        {

            if (e.AddedItems.Count == 0) return;

            photoCamera.Resolution = (Size)e.AddedItems[0];

            textblock2.Text = "已将分辨率设置为:" + photoCamera.Resolution.ToString();

        }



    }

2.PhotoCaptureDevice

PhotoCaptureDevice对相机的高级捕获很多都是用于支持后续版本的,下面我们简单演示下通过PhotoCaptureDevice捕获照片并显示出来的方法。

[XAML]
    <Grid x:Name="LayoutRoot" Background="Transparent">

        <Canvas x:Name="canvas1" Margin="0,0,0,0" Width="800" Height="480">

            <Canvas.Background>

                <VideoBrush x:Name="viewfinderBrush" />

            </Canvas.Background>

           <Button Content="拍照" Canvas.Left="653" Canvas.Top="383" Click="Button_Click_1"/>

            <Image x:Name="img1" Height="231" Canvas.Left="508" Canvas.Top="87" Width="220"/>

        </Canvas>

 </Grid>

[C#]
    public partial class MainPage : PhoneApplicationPage

    {

        // 构造函数

        public MainPage()

        {

            InitializeComponent();



        }

        PhotoCaptureDevice photoCaptureDevice;

        CameraCaptureSequence cameraCaptureSequence;

        MemoryStream captureStream = new MemoryStream();

        protected async override void OnNavigatedTo(NavigationEventArgs e)

        {

            if (PhotoCaptureDevice.AvailableSensorLocations.Contains(CameraSensorLocation.Back))

            {

                var SupportedResolutions = PhotoCaptureDevice.GetAvailableCaptureResolutions(CameraSensorLocation.Back);

                photoCaptureDevice = await PhotoCaptureDevice.OpenAsync(CameraSensorLocation.Back, SupportedResolutions[0]);

            }

            else if (PhotoCaptureDevice.AvailableSensorLocations.Contains(CameraSensorLocation.Front))

            {

                var SupportedResolutions = PhotoCaptureDevice.GetAvailableCaptureResolutions(CameraSensorLocation.Front);

                photoCaptureDevice = await PhotoCaptureDevice.OpenAsync(CameraSensorLocation.Front, SupportedResolutions[0]);

            }

            else

            {

                return;

            }

            viewfinderBrush.SetSource(photoCaptureDevice);



            



            cameraCaptureSequence = photoCaptureDevice.CreateCaptureSequence(1);



            // Set camera properties.

            photoCaptureDevice.SetProperty(KnownCameraPhotoProperties.FlashMode, FlashState.On);

            photoCaptureDevice.SetProperty(KnownCameraGeneralProperties.PlayShutterSoundOnCapture, true);

            photoCaptureDevice.SetProperty(KnownCameraGeneralProperties.AutoFocusRange, AutoFocusRange.Infinity);



            cameraCaptureSequence.Frames[0].DesiredProperties[KnownCameraPhotoProperties.SceneMode] = CameraSceneMode.Portrait;



            cameraCaptureSequence.Frames[0].CaptureStream = captureStream.AsOutputStream();

            await photoCaptureDevice.PrepareCaptureSequenceAsync(cameraCaptureSequence);

            base.OnNavigatedTo(e);

        }



        public async void Capture()

        {

            await cameraCaptureSequence.StartCaptureAsync();

            var b = new BitmapImage();

            b.SetSource(captureStream);

            img1.Source = b;



        }



        private void Button_Click_1(object sender, RoutedEventArgs e)

        {

            Capture();

        }



    }

 

三、罗盘传感器

罗盘传感器用于感知地球磁场,功能主要是用于确定方向,有了它,我们可以开发类似指南针的应用。

不是每个设备都必须支持罗盘传感器的,所以我们需要在使用前判断设备是否支持。

[C#]
 if (!Compass.IsSupported)

 {

     MessageBox.Show("设备不支持罗盘");

     return;

 }

 

如果设备支持,我们还需要判断罗盘的精度,如果精度不高,需要提醒用户校对精度。当罗盘获取数据时,通过CurrentValueChanged事件处理获取的数据。

[XAML]
<Canvas x:Name="canvas1" Background="Black" Visibility="Collapsed">

    <Image x:Name="image3" Canvas.Top="12" Canvas.Left="70" Source="Image/3.png"/>

    <TextBlock TextWrapping="Wrap" Width="450" Canvas.Top="240" Text="  您的罗盘需要校验,请按照上图所示的方式移动您的手机,系统将自动完成校验过程。" />

    <Button Content="完成校验" Canvas.Left="154" Canvas.Top="596" Click="Button_Click_1"/>

</Canvas>

 

[C#]
compass = new Compass();

//指定数据更新时间间隔.

compass.TimeBetweenUpdates = TimeSpan.FromMilliseconds(20);

//从罗盘传感器获取数据时发生

compass.CurrentValueChanged += new EventHandler<SensorReadingEventArgs<CompassReading>>(compass_CurrentValueChanged);

//罗盘需要校验时发生

compass.Calibrate += new EventHandler<CalibrationEventArgs>(compass_Calibrate);
compass.Start(); //从传感器获取新数据时发生 void compass_CurrentValueChanged(object sender, SensorReadingEventArgs<CompassReading> e) { //获取到地球地理北极顺时值偏移角度 trueHeading = e.SensorReading.TrueHeading; } //罗盘需要校验时发生 void compass_Calibrate(object sender, CalibrationEventArgs e) { Dispatcher.BeginInvoke(() => { //罗盘需要校验,canvas1指示用户校验 canvas1.Visibility = Visibility.Visible; }); }

 

四、加速度计

加速度计用于测试某个时刻设备在空间中的姿态。它与重力相关。它的取值在分为x、y、z三个方向取值,下面我们理解下这些取值含义。我们假设设备正面向上平躺在水平桌面为参照标准:
    x:设备左倾的趋势越大,值越小,左倾90度时,值为-1;相反,右倾时值越大,最大为1。
    y:设备后倾的趋势越大,值越小,后倾90度时,值为-1;相反,前倾时值越大,最大为1。
    z:设备下倾的趋势越大,值越大,下倾180度(翻面了)时,值为1;正面朝上(不动)时,最为-1。

总的说来,x控制左右,y控制前后,z控制上下。下面我们在看看如何使用。 

  [C#]
//校验设备是否支持

if (!Accelerometer.IsSupported)

{

    MessageBox.Show("设备不支持重力感应");

}



var accelerometer = new Accelerometer();

accelerometer.TimeBetweenUpdates = TimeSpan.FromMilliseconds(20);

//从加速度传感器获取数据时发生

accelerometer.CurrentValueChanged += new EventHandler<SensorReadingEventArgs<AccelerometerReading>>(accelerometer_CurrentValueChanged);

accelerometer.Start();



//从加速度传感器获取数据时发生

void accelerometer_CurrentValueChanged(object sender, SensorReadingEventArgs<AccelerometerReading> e)

{

    //获取到设备加速度矢量

    vector3 = e.SensorReading.Acceleration;

}

 

五、陀螺仪

陀螺仪用于检测设备在空间中的旋转趋势。它的三个取值即为设备绕三个坐标轴的旋转速度。
    x:水平左右向轴的旋转速度。
    y:水平前后向轴的旋转速度。
    z:垂直上下向轴的旋转速度。

然后我们看看如何调用陀螺仪。

[C#]
//判断设备是否支持陀螺仪

if (!Gyroscope.IsSupported)

{

    MessageBox.Show("设备不支持陀螺仪");

}



gyroscope = new Gyroscope();

gyroscope.TimeBetweenUpdates = TimeSpan.FromMilliseconds(20);

//从陀螺仪获取数据时发生

gyroscope.CurrentValueChanged += new EventHandler<SensorReadingEventArgs<GyroscopeReading>>(gyroscope_CurrentValueChanged);



//启动陀螺仪,实际使用可能启动失败需要捕获异常

gyroscope.Start();



//从陀螺仪获取数据是发生

void gyroscope_CurrentValueChanged(object sender, SensorReadingEventArgs<GyroscopeReading> e)

{

    //获取设备绕每个轴的旋转速度

    var rotationRate = e.SensorReading.RotationRate;

}

 

六、如何振动手机

手机的振动可以通过一句简单的API完成,在某些情况下可能还需要设置振动的世界,以及提前结束振动。下面代码演示了如何操作。

 [C#]
            VibrateController testVibrateController = VibrateController.Default;

            //定义振动时间

            testVibrateController.Start(TimeSpan.FromSeconds(3));

            //在振动时间达到前停止振动

            testVibrateController.Stop();

 

作者:[ Lipan]
出处:[ http://www.cnblogs.com/lipan/]
版权声明:本文的版权归作者与博客园共有。转载时须注明原文出处以及作者,并保留原文指向型链接,不得更改原文内容。否则作者将保留追究其法律责任。

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