Silverlight实用窍门系列：17.中心点联动多线的可拖动控件（绘制工程图、拓扑图基础）【附带源码实例】

< Image x:Name = " green "  Source = " green.png "  Width = " 44 "  Canvas.ZIndex = " 300 "  Height = " 44 " ></ Image >

public   partial   class  ucLine : UserControl
{
public  ucLine()
{
InitializeComponent();
dragBehavior.Attach( this .green);
dragBehavior.Dragging  +=   new  MouseEventHandler(dragBehavior_Dragging);
}
MouseDragElementBehavior dragBehavior  =   new  MouseDragElementBehavior();
private   double  _R;
private   double  _AngleAll;
private   double  _centerX;
private   double  _centerY;

///   <summary>
///  中心圆半径
///   </summary>
public   double  R
{
get  {  return  _R; }
set  { _R  =  value; }
}
private   double  _X2;
private   double  _Y2;
///   <summary>
///  指定本控件的X2坐标
///   </summary>
public   double  X2
{
get  {  return  _X2; }
set
{
_X2  =  value;
this .LineD.X2  =   this .X2;
}
}
///   <summary>
///  指定本控件的Y2坐标
///   </summary>
public   double  Y2
{
get  {  return  _Y2; }
set
{
_Y2  =  value;
this .LineD.Y2  =   this .Y2;
}
}
///   <summary>
///  本控件的中心原点X坐标
///   </summary>
public   double  CenterX
{
get  {  return  _centerX; }
set
{
_centerX  =  value;
this .LineD.X1  =  _centerX;
}
}
///   <summary>
///  本控件的中心原点Y坐标
///   </summary>
public   double  CenterY
{
get  {  return  _centerY; }
set
{
_centerY  =  value;
this .LineD.Y1  =  _centerY;
}
}
///   <summary>
///  本控件的起始线弧度
///   </summary>
public   double  AngleAll
{
get  {  return  _AngleAll; }
set
{
_AngleAll  =  value;
// 计算得到角度，然后复制给线的终点坐标位置。注意：设置线终点坐标时须加入线的起点位置
double  sinAngle  =  Math.Sin( this .AngleAll  *  Math.PI  /   180 );
double  cosAngle  =  Math.Cos( this .AngleAll  *  Math.PI  /   180 );
this .LineD.X2  =  cosAngle  *   this .R  +   this .CenterX;
this .LineD.Y2  =   this .CenterY  -  sinAngle  *   this .R;
// 设置绿色球的坐标位置。
this .green.SetValue(Canvas.LeftProperty,  this .LineD.X2  -   22 );
this .green.SetValue(Canvas.TopProperty,  this .LineD.Y2  -   22 );
}
}
///   <summary>
///  green被拖动的时候触发的事件
///   </summary>
///   <param name="sender"></param>
///   <param name="e"></param>
void  dragBehavior_Dragging( object  sender, MouseEventArgs e)
{
MouseDragElementBehavior dragBehavior2  =  sender  as  MouseDragElementBehavior;
double  x1  =  dragBehavior2.X  +   22 ;
double  y1  =  dragBehavior2.Y  +   22 ;
// 设置本条线的结尾点坐标为拖动后的坐标
this .LineD.X2  =  x1;
this .LineD.Y2  =  y1;
}
}