WP7应用开发笔记(4)圆形滑动控件实现

<UserControl
xmlns&＃61;"http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x&＃61;"http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d&＃61;"http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc&＃61;"http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local&＃61;"clr-namespace:VirtualKeyboard.Controls"
mc:Ignorable&＃61;"d"
x:Class&＃61;"VirtualKeyboard.Controls.LoopControl"
d:DesignWidth&＃61;"340" d:DesignHeight&＃61;"340">

<Canvas>
<Ellipse x:Name&＃61;"bigEllipse" Height&＃61;"340" Width&＃61;"340" Canvas.Left&＃61;"0" Canvas.Top&＃61;"0" StrokeThickness&＃61;"4" Stroke&＃61;"White" Fill&＃61;"#FF7A7A7A" />
<local:RoundButton x:Name&＃61;"centerButton" Height&＃61;"150" Width&＃61;"150" Canvas.Left&＃61;"95" Canvas.Top&＃61;"95" ImageSource&＃61;"/VirtualKeyboard.Controls;component/Icons/word.ok.png" Background&＃61;"#FF1D1D1D"/>
Canvas>
UserControl>

public partial class LoopControl
{
#region Const
const double BigRadius &＃61; 200.0;
const double SmailRadius &＃61; 70.0;
private readonly TimeSpan deltaSpan &＃61; new TimeSpan(0, 0, 0, 0, 200);
#endregion

#region Private
private DateTime startTime;
private Angle startAngle;
#endregion

public event RoutedEventHandler CenterClick
{
add { centerButton.Click &＃43;&＃61; value; }
remove { centerButton.Click -&＃61; value; }
}

public event EventHandler LoopGlide;

public void OnLoopGlide(LoopGlideEventArg e)
{
EventHandler handler &＃61; LoopGlide;
if (handler !&＃61; null) handler(this, e);
}

public LoopControl()
{
// 为初始化变量所必需
InitializeComponent();
}


protected override void OnManipulationStarted(ManipulationStartedEventArgs e)
{
startTime &＃61; DateTime.Now;
startAngle &＃61; ToAngle(e.ManipulationOrigin);
base.OnManipulationStarted(e);
}

protected override void OnManipulationDelta(ManipulationDeltaEventArgs e)
{
if (IsInCenter(e.ManipulationOrigin)) return;

var now &＃61; DateTime.Now;
if (now - startTime > deltaSpan)
{
GetDirection(e.ManipulationOrigin);
startTime &＃61; now;
startAngle &＃61; ToAngle(e.ManipulationOrigin);
}
base.OnManipulationDelta(e);
}

private void GetDirection(Point point)
{
var angle &＃61; ToAngle(point);
var angleDistance &＃61; startAngle - angle;
OnLoopGlide(new LoopGlideEventArg(angleDistance.Distance));
}

///

/// 求角度
///

///
///
private Angle ToAngle(Point point)
{
var xPoint &＃61; ToXPoint(point);
var x &＃61; xPoint.X;
var y &＃61; xPoint.Y;
var angle &＃61; Math.Atan(x / y) * 180.0 / Math.PI;
if (!(y <0.0))
{
angle &＃43;&＃61; 180.0;
}
else if (x > 0.0)
{
angle &＃43;&＃61; 360.0;
}
return new Angle(angle);
}

///

/// 变化坐标
///

///
///
private Point ToXPoint(Point point)
{
var x &＃61; point.X - BigRadius;
var y &＃61; point.Y - BigRadius;
return new Point(x, y);
}

private bool IsInCenter(Point point)
{
var xPoint &＃61; ToXPoint(point);
var radius &＃61; Math.Sqrt(xPoint.X * xPoint.X &＃43; xPoint.Y * xPoint.Y);
return radius }

#region Private Struct

///

/// 角度
///

private struct Angle : IEquatable
{
private readonly double value;
private const double Epsilon &＃61; 0.1;

public double Value
{
get { return value; }
}

public Angle(double value)
{
if (value > 360.0 || value <0)
{
throw new ArgumentOutOfRangeException("value", "value must between 0 and 360");
}
this.value &＃61; value;
}

public override string ToString()
{
return string.Format("{0:N2}", value);
}

public static AngleDistance operator -(Angle angle1, Angle angle2)
{
double angleDistance &＃61; angle1.value - angle2.value;
if (angleDistance > 180.0)
{
angleDistance -&＃61; 360;
}
else if (angleDistance <-180.0)
{
angleDistance &＃43;&＃61; 360;
}
return new AngleDistance(angleDistance);
}

public override bool Equals(object obj)
{
if (obj is Angle)
{
return Equals((Angle)obj);
}
return false;
}

public override int GetHashCode()
{
return 360 ^ value.GetHashCode();
}

public bool Equals(Angle other)
{
return Math.Abs(value - other.value) }
}

///

/// 夹角
///

private struct AngleDistance
{
private readonly double angleDistance;

public AngleDistance(double angleDistance)
{
this.angleDistance &＃61; angleDistance;
}

public double Distance
{
get { return angleDistance; }
}

public override string ToString()
{
return string.Format("{0:N2}", angleDistance);
}

///

/// 顺时针
///

public bool Clockwise
{
get { return angleDistance > 0; }
}
}
#endregion


}