private void OnDragDelta(object sender, DragDeltaEventArgs e)
{
if (!GetTargetIsEditable())
{
e.Handled = true;
return;
}
CustomThumb thumb = e.OriginalSource as CustomThumb;
if (thumb == null)
{
return;
}
double VerticalChange = e.VerticalChange;
double HorizontalChange = e.HorizontalChange;
Rect NewBound = Rect.Empty;
if (thumb.DragDirection == DragDirection.MiddleCenter)
{
NewBound = DragElement(HorizontalChange, VerticalChange);
}
else
{
NewBound = ResizeElement(thumb, HorizontalChange, VerticalChange);
}
RaisenDragChangingEvent(NewBound);
SetTargetActualBound(NewBound);
e.Handled = true;
}
private Rect ResizeElement(CustomThumb HitedThumb, double HorizontalChange, double VerticalChange)
{
#region Get Old Value
if (HitedThumb == null)
{
return(Rect.Empty);
}
Rect TargetActualBound = GetTargetActualBound();
double TopOld = CorrectDoubleValue(TargetActualBound.Y);
double LeftOld = CorrectDoubleValue(TargetActualBound.X);
double WidthOld = CorrectDoubleValue(TargetActualBound.Width);
double HeightOld = CorrectDoubleValue(TargetActualBound.Height);
double TopNew = TopOld;
double LeftNew = LeftOld;
double WidthNew = WidthOld;
double HeightNew = HeightOld;
#endregion
if (HitedThumb.DragDirection == DragDirection.TopLeft ||
HitedThumb.DragDirection == DragDirection.MiddleLeft ||
HitedThumb.DragDirection == DragDirection.BottomLeft)
{
ResizeFromLeft(DragHelperParent, LeftOld, WidthOld, HorizontalChange, out LeftNew, out WidthNew);
}
if (HitedThumb.DragDirection == DragDirection.TopLeft ||
HitedThumb.DragDirection == DragDirection.TopCenter ||
HitedThumb.DragDirection == DragDirection.TopRight)
{
ResizeFromTop(DragHelperParent, TopOld, HeightOld, VerticalChange, out TopNew, out HeightNew);
}
if (HitedThumb.DragDirection == DragDirection.TopRight ||
HitedThumb.DragDirection == DragDirection.MiddleRight ||
HitedThumb.DragDirection == DragDirection.BottomRight)
{
ResizeFromRight(DragHelperParent, LeftOld, WidthOld, HorizontalChange, out WidthNew);
}
if (HitedThumb.DragDirection == DragDirection.BottomLeft ||
HitedThumb.DragDirection == DragDirection.BottomCenter ||
HitedThumb.DragDirection == DragDirection.BottomRight)
{
ResizeFromBottom(DragHelperParent, TopOld, HeightOld, VerticalChange, out HeightNew);
}
this.Width = WidthNew;
this.Height = HeightNew;
Canvas.SetTop(this, TopNew);
Canvas.SetLeft(this, LeftNew);
return(new Rect
{
X = LeftNew,
Y = TopNew,
Width = WidthNew,
Height = HeightNew
});
}
private Rect ResizeElement(CustomThumb HitedThumb, double HorizontalChange, double VerticalChange)
{
#region Get Old Value
if (HitedThumb == null)
{
return(Rect.Empty);
}
this.HorizontalDelta += (int)HorizontalChange;
this.VerticalDelta += (int)VerticalChange;
Rect TargetActualBound = GetTargetActualBound();
//System.Console.WriteLine(string.Format("HorizontalDelta:{0},VerticalDelta:{1}", HorizontalDelta, VerticalDelta));
//如果偏移小于阈值，不重置大小
if ((this.HorizontalChangeThreshold != 0 && this.VerticalChangeThreshold != 0) &&
(this.HorizontalDelta / this.HorizontalChangeThreshold != 0 &&
this.VerticalDelta / this.VerticalChangeThreshold != 0))
{
return(TargetActualBound);
}
if (this.HorizontalChangeThreshold > 0)
{
this.HorizontalDelta = this.HorizontalDelta / this.HorizontalChangeThreshold != 0 ?
(this.HorizontalDelta >= this.HorizontalChangeThreshold ? this.HorizontalChangeThreshold : -this.HorizontalChangeThreshold) : 0;
}
if (this.VerticalChangeThreshold > 0)
{
this.VerticalDelta = this.VerticalDelta / this.VerticalChangeThreshold != 0 ?
(this.VerticalDelta >= this.VerticalChangeThreshold ? this.VerticalChangeThreshold : -this.VerticalChangeThreshold) : 0;
}
double TopOld = CorrectDoubleValue(TargetActualBound.Y);
double LeftOld = CorrectDoubleValue(TargetActualBound.X);
double WidthOld = CorrectDoubleValue(TargetActualBound.Width);
double HeightOld = CorrectDoubleValue(TargetActualBound.Height);
double TopNew = TopOld;
double LeftNew = LeftOld;
double WidthNew = WidthOld;
double HeightNew = HeightOld;
//System.Console.WriteLine(string.Format("HorizontalDelta:{0},VerticalDelta:{1}", HorizontalDelta, VerticalDelta));
#endregion
if (HitedThumb.DragDirection == DragDirection.TopLeft ||
HitedThumb.DragDirection == DragDirection.MiddleLeft ||
HitedThumb.DragDirection == DragDirection.BottomLeft)
{
this.ResizeFromLeft(DragHelperParent, LeftOld, WidthOld, this.HorizontalDelta, out LeftNew, out WidthNew);
}
if (HitedThumb.DragDirection == DragDirection.TopLeft ||
HitedThumb.DragDirection == DragDirection.TopCenter ||
HitedThumb.DragDirection == DragDirection.TopRight)
{
this.ResizeFromTop(DragHelperParent, TopOld, HeightOld, this.VerticalDelta, out TopNew, out HeightNew);
}
if (HitedThumb.DragDirection == DragDirection.TopRight ||
HitedThumb.DragDirection == DragDirection.MiddleRight ||
HitedThumb.DragDirection == DragDirection.BottomRight)
{
this.ResizeFromRight(DragHelperParent, LeftOld, WidthOld, this.HorizontalDelta, out WidthNew);
}
if (HitedThumb.DragDirection == DragDirection.BottomLeft ||
HitedThumb.DragDirection == DragDirection.BottomCenter ||
HitedThumb.DragDirection == DragDirection.BottomRight)
{
this.ResizeFromBottom(DragHelperParent, TopOld, HeightOld, this.VerticalDelta, out HeightNew);
}
this.Width = WidthNew;
this.Height = HeightNew;
Canvas.SetTop(this, TopNew);
Canvas.SetLeft(this, LeftNew);
this.HorizontalDelta = 0;
this.VerticalDelta = 0;
return(new Rect
{
X = LeftNew,
Y = TopNew,
Width = WidthNew,
Height = HeightNew
});
}