| public ScrollToVerticalOffset ( double offset ) : void | ||
| offset | double | The position that the content scrolls to. |
| Résultat | void | |
/// <summary>
/// Scroll a ScrollViewer vertically by a given offset.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <param name="offset">The vertical offset to scroll.</param>
private static void ScrollByVerticalOffset(ScrollViewer viewer, double offset)
{
Debug.Assert(viewer != null, "viewer should not be null!");
offset += viewer.VerticalOffset;
offset = Math.Max(Math.Min(offset, viewer.ExtentHeight), 0);
viewer.ScrollToVerticalOffset(offset);
}
/// <summary>
/// Scroll a ScrollViewer vertically by a given offset.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <param name="offset">The vertical offset to scroll.</param>
private static void ScrollByVerticalOffset(ScrollViewer viewer, double offset)
{
Debug.Assert(viewer != null, "viewer should not be null!");
offset += viewer.VerticalOffset;
offset = CoerceVerticalOffset(viewer, offset);
viewer.ScrollToVerticalOffset(offset);
}
/// <summary>
/// Scroll a ScrollViewer vertically by a given offset.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <param name="offset">The vertical offset to scroll.</param>
private static void ScrollByVerticalOffset(ScrollViewer viewer, double offset)
{
Debug.Assert(viewer != null, "viewer should not be null!");
offset += viewer.VerticalOffset;
offset = Math.Max(Math.Min(offset, viewer.ExtentHeight), 0);
viewer.ScrollToVerticalOffset(offset);
}
/// <summary>
/// Scroll the ScrollViewer to the top.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="viewer" /> is null.
/// </exception>
public static void ScrollToTop(this ScrollViewer viewer)
{
if (viewer == null)
{
throw new ArgumentNullException("viewer");
}
viewer.ScrollToVerticalOffset(0);
}
/// <summary>
/// Scroll the ScrollViewer to the bottom.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="viewer" /> is null.
/// </exception>
public static void ScrollToBottom(this ScrollViewer viewer)
{
if (viewer == null)
{
throw new ArgumentNullException("viewer");
}
viewer.ScrollToVerticalOffset(viewer.ExtentHeight);
}
private static void OnVerticalOffsetChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
System.Windows.Controls.ScrollViewer scrollViewer = target as System.Windows.Controls.ScrollViewer;
if (scrollViewer != null)
{
scrollViewer.ScrollToVerticalOffset((double)e.NewValue);
}
}
/// <summary>
/// VerticalOffsetProperty property changed handler.
/// </summary>
/// <param name="dependencyObject">ScrollViewer that changed its VerticalOffset.</param>
/// <param name="eventArgs">Event arguments.</param>
private static void OnVerticalOffsetPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs eventArgs)
{
ScrollViewer source = dependencyObject as ScrollViewer;
if (source == null)
{
throw new ArgumentNullException("dependencyObject");
}
source.ScrollToVerticalOffset((double)eventArgs.NewValue);
}
void OnCursorPositionChanged(object sender, CursorPositionChangedEventArgs args)
{
if (contentElement == null)
{
contentElement = GetTemplateChild("ContentElement");
}
if (contentElement != null && contentElement is ScrollViewer)
{
ScrollViewer scrollview = contentElement as ScrollViewer;
double offset = scrollview.HorizontalOffset;
// Note: for horizontal scrollage, we offset by 1.0 pixel for the width of the cursor ibeam
if (args.CursorX < offset)
{
// need to scroll to the left a bit
scrollview.ScrollToHorizontalOffset(Math.Max(args.CursorX - 1.0, 0.0));
}
else if (args.CursorX > offset + scrollview.ViewportWidth)
{
// need to scroll to the right
offset = (args.CursorX + 1.0) - scrollview.ViewportWidth;
scrollview.ScrollToHorizontalOffset(offset);
}
offset = scrollview.VerticalOffset;
if (args.CursorY < offset)
{
// need to scroll up a bit
scrollview.ScrollToVerticalOffset(args.CursorY);
}
else if (args.CursorY + args.CursorHeight > offset + scrollview.ViewportHeight)
{
// need to scroll down a bit
offset = (args.CursorY + args.CursorHeight) - Math.Max(args.CursorHeight, scrollview.ViewportHeight);
scrollview.ScrollToVerticalOffset(offset);
}
}
}
public void OnScrollChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
Invoke(() => {
double old = e.OldValue == null ? 0 : (double)e.OldValue;
double a = (double)e.NewValue;
if (((double)e.NewValue - old) % 3 == 0)
{
a = a > old ? old + 1 : old - 1; //获取滚动条位置变化后的属性值
}
sv1.ScrollToVerticalOffset(a);
sv2.ScrollToVerticalOffset(a);
});
}
/// <summary>
/// Handles the mouse wheel event.
/// </summary>
/// <param name="sender">The ScrollViewer.</param>
/// <param name="e">Event arguments.</param>
private static void OnMouseWheel(object sender, MouseWheelEventArgs e)
{
ScrollViewer viewer = sender as ScrollViewer;
Debug.Assert(viewer != null, "sender should be a non-null ScrollViewer!");
Debug.Assert(e != null, "e should not be null!");
if (!e.Handled)
{
double position = CoerceVerticalOffset(viewer, viewer.VerticalOffset - e.Delta);
viewer.ScrollToVerticalOffset(position);
e.Handled = true;
}
}
static void AutoScroll(Point positionInScrollViewer, ScrollViewer scrollViewer, Point? positionInLogicalView, FrameworkElement logicalView, double scrollOnDragThresholdX, double scrollOnDragThresholdY, int scrollOnDragOffset)
{
double scrollViewerWidth = scrollViewer.ActualWidth;
double scrollViewerHeight = scrollViewer.ActualHeight;
double logicalViewWidth = 0;
double logicalViewHeight = 0;
if (logicalView != null)
{
logicalViewWidth = logicalView.ActualWidth;
logicalViewHeight = logicalView.ActualHeight;
}
int heightToScroll = 0;
int widthToScroll = 0;
if (positionInScrollViewer.X > (scrollViewerWidth - scrollOnDragThresholdX)
&& (positionInLogicalView == null
|| positionInLogicalView.Value.X < (logicalViewWidth - scrollBuffer)))
{
widthToScroll = scrollOnDragOffset;
}
else if (positionInScrollViewer.X < scrollOnDragThresholdX
&& (positionInLogicalView == null
|| positionInLogicalView.Value.X > scrollBuffer))
{
widthToScroll = -scrollOnDragOffset;
}
if (positionInScrollViewer.Y > (scrollViewerHeight - scrollOnDragThresholdY)
&& (positionInLogicalView == null
|| positionInLogicalView.Value.Y < logicalViewHeight - scrollBuffer))
{
heightToScroll = scrollOnDragOffset;
}
else if (positionInScrollViewer.Y < scrollOnDragThresholdY
&& (positionInLogicalView == null
|| positionInLogicalView.Value.Y > scrollBuffer))
{
heightToScroll = -scrollOnDragOffset;
}
if (widthToScroll != 0 || heightToScroll != 0)
{
scrollViewer.ScrollToVerticalOffset(scrollViewer.VerticalOffset + heightToScroll);
scrollViewer.ScrollToHorizontalOffset(scrollViewer.HorizontalOffset + widthToScroll);
}
}
protected override void OnPreviewMouseMove(MouseEventArgs e)
{
if (e.LeftButton == Input.MouseButtonState.Pressed)
{
try
{
var p = e.GetPosition(this);
if (p.X < 0 || p.X > this.ActualWidth || p.Y < 0 || p.Y > this.ActualHeight)
{
OnPreviewMouseLeftButtonUp(new MouseButtonEventArgs(e.MouseDevice, e.Timestamp, Input.MouseButton.Left));
return;
}
if (double.IsNaN(last) || double.IsNaN(start))
{
startTime = e.Timestamp;
if (orientation == Orientation.Horizontal)
{
start = p.X;
last = p.X;
}
else
{
start = p.Y;
last = p.Y;
}
return;
}
if (orientation == Orientation.Horizontal)
{
var x = p.X;
var length = scrollViewer.HorizontalOffset - x + last;
if (length < 0)
{
length = 0;
}
else if (length > scrollViewer.ScrollableWidth)
{
length = scrollViewer.ScrollableWidth;
}
scrollViewer.ScrollToHorizontalOffset(length);
last = x;
}
else
{
var y = p.Y;
var length = scrollViewer.VerticalOffset - y + last;
if (length < 0)
{
length = 0;
}
else if (length > scrollViewer.ScrollableHeight)
{
length = scrollViewer.ScrollableHeight;
}
scrollViewer.ScrollToVerticalOffset(length);
last = y;
}
e.Handled = true;
}
catch { }
}
}
public static void ScrollToCenter(ScrollViewer scrollViewer)
{
scrollViewer.ScrollToHorizontalOffset(scrollViewer.ExtentWidth / 2 - scrollViewer.Width / 2);
scrollViewer.ScrollToVerticalOffset(scrollViewer.ExtentHeight / 2 - scrollViewer.Height / 2);
}
/// <summary>
/// Scroll the ScrollViewer to the bottom.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
public static void ScrollToBottom(this ScrollViewer viewer)
{
Debug.Assert(viewer != null, "viewer should not be null!");
viewer.ScrollToVerticalOffset(viewer.ExtentHeight);
}
/// <summary>
/// Scroll the ScrollViewer to the top.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
public static void ScrollToTop(this ScrollViewer viewer)
{
Debug.Assert(viewer != null, "viewer should not be null!");
viewer.ScrollToVerticalOffset(0);
}
/// <summary>
/// Shows log file in a separate child window on top
/// </summary>
public static void ShowLog()
{
var popup = new Popup();
var text = new TextBlock();
text.Width = 800;
text.TextWrapping = TextWrapping.Wrap;
try
{
text.Text = GetLogContents();
}
catch (Exception exception)
{
text.Text = string.Format("Cannot open log file, exception is\n {0}", exception.ToString());
}
var closeButton = new Button();
closeButton.Content = "Close";
closeButton.Click += (s, e) => popup.IsOpen = false;
var scroll = new ScrollViewer();
scroll.Background = new SolidColorBrush(Colors.White);
scroll.Content = text;
scroll.Height = 400;
var content = new StackPanel();
content.Children.Add(scroll);
content.Children.Add(closeButton);
popup.Child = content;
popup.IsOpen = true;
// scroll to the bottom
scroll.UpdateLayout();
scroll.ScrollToVerticalOffset(double.MaxValue);
}
/// <summary>
/// Scrolls grid content if necessary.
/// </summary>
/// <param name="yPos">Dragged object position.</param>
/// <param name="scrollViewer">Scroll viewer.</param>
private void _DoAutoScroll(double yPos, ScrollViewer scrollViewer)
{
double bottomTolerance = BOTTOM_TOLERANCE;
double topTolerance = _rowHeight * 2;
Debug.Assert(_rowHeight != 0); // Must be initialized.
if (scrollViewer == null)
return;
if (yPos < topTolerance) // Top of visible list?
{
// Scroll up.
scrollViewer.ScrollToVerticalOffset(scrollViewer.VerticalOffset - _rowHeight);
}
else if (yPos > this.ActualHeight - bottomTolerance) //Bottom of visible list?
{
//Scroll down.
scrollViewer.ScrollToVerticalOffset(scrollViewer.VerticalOffset + _rowHeight);
}
}
/// <summary>
/// Handles scrolling the specified scroll viewer if the drag event indicates the drag
/// operation is nearing the scroll viewers top or bottom boundaries.
/// </summary>
/// <param name="scrollViewer">The scroll viewer.</param>
/// <param name="e">
/// The <see cref="System.Windows.DragEventArgs" /> instance containing the event data.
/// </param>
private static void HandleDragScrolling(ScrollViewer scrollViewer, DragEventArgs e)
{
const int threshold = 20;
const int offset = 10;
var mousePoint = e.GetPosition(scrollViewer);
if (mousePoint.Y < threshold)
{
scrollViewer.ScrollToVerticalOffset(scrollViewer.VerticalOffset - offset);
}
else if (mousePoint.Y > (scrollViewer.ActualHeight - threshold))
{
scrollViewer.ScrollToVerticalOffset(scrollViewer.VerticalOffset + offset);
}
}
static ScrollViewer AddScrollViewerMouseWheelSupport(ScrollViewer scrollViewer, double scrollAmount)
{
if(mouseWheelHelper != null)
{
mouseWheelHelper.MouseWheelMoved += (source, eventArgs) =>
{
var delta = eventArgs.WheelDelta;
delta *= scrollAmount;
if (eventArgs.IsHorizontal)
{
var newOffset = scrollViewer.HorizontalOffset - delta;
if (newOffset > scrollViewer.ScrollableWidth)
newOffset = scrollViewer.ScrollableWidth;
else if (newOffset < 0)
newOffset = 0;
scrollViewer.ScrollToHorizontalOffset(newOffset);
}
else
{
var newOffset = scrollViewer.VerticalOffset - delta;
if (newOffset > scrollViewer.ScrollableHeight)
newOffset = scrollViewer.ScrollableHeight;
else if (newOffset < 0)
newOffset = 0;
scrollViewer.ScrollToVerticalOffset(newOffset);
}
eventArgs.BrowserEventHandled = true;
};
}
return scrollViewer;
}
/// <summary>
/// 滑动改变
/// </summary>
/// <param name="isLeft">滑动方向 </param>
/// <param name="scrollViewer">自动调整的控件</param>
/// <param name="width">单个间隔的宽度</param>
public int TranslationChanged(bool isLeft,ScrollViewer scrollViewer,double width)
{
int newSelected;
if (!isLeft)
{
newSelected = _selecter + 1;
}
else
{
newSelected = _selecter - 1;
}
//循环切换
if (newSelected < 0) newSelected = _effects.Count - 1;
if (newSelected >= _effects.Count) newSelected = 0;
//自动调整位置
if (newSelected >= 3)
{
//判断方向
if (scrollViewer.HorizontalScrollBarVisibility != ScrollBarVisibility.Disabled)
{
scrollViewer.ScrollToHorizontalOffset(width * (newSelected - 2));
}
else
{
scrollViewer.ScrollToVerticalOffset(width * (newSelected - 2));
}
}
else
{
if (scrollViewer.HorizontalScrollBarVisibility != ScrollBarVisibility.Disabled)
{
scrollViewer.ScrollToHorizontalOffset(0);
}
else
{
scrollViewer.ScrollToVerticalOffset(0);
}
}
//变化效果
SelectedChanged(newSelected);
return newSelected;
}
internal void ScrollIntoView(FrameworkElement element)
{
// Get the ScrollHost
ScrollViewer scrollHost = ScrollHost;
if (scrollHost == null)
{
return;
}
// Get the position of the element relative to the ScrollHost
GeneralTransform transform = null;
try
{
transform = element.TransformToVisual(scrollHost);
}
catch (ArgumentException)
{
// Ignore failures when not in the visual tree
return;
}
Rect itemRect = new Rect(
transform.Transform(new Point()),
transform.Transform(new Point(element.ActualWidth, element.ActualHeight)));
// Scroll vertically
double verticalOffset = scrollHost.VerticalOffset;
double verticalDelta = 0;
double hostBottom = scrollHost.ViewportHeight;
double itemBottom = itemRect.Bottom;
if (hostBottom < itemBottom)
{
verticalDelta = itemBottom - hostBottom;
verticalOffset += verticalDelta;
}
double itemTop = itemRect.Top;
if (itemTop - verticalDelta < 0)
{
verticalOffset -= verticalDelta - itemTop;
}
scrollHost.ScrollToVerticalOffset(verticalOffset);
// Scroll horizontally
double horizontalOffset = scrollHost.HorizontalOffset;
double horizontalDelta = 0;
double hostRight = scrollHost.ViewportWidth;
double itemRight = itemRect.Right;
if (hostRight < itemRight)
{
horizontalDelta = itemRight - hostRight;
horizontalOffset += horizontalDelta;
}
double itemLeft = itemRect.Left;
if (itemLeft - horizontalDelta < 0)
{
horizontalOffset -= horizontalDelta - itemLeft;
}
scrollHost.ScrollToHorizontalOffset(horizontalOffset);
}
private void set(ScrollChangedEventArgs e, ScrollViewer sv, Canvas canvas)
{
if (e.ExtentHeightChange != 0 || e.ExtentWidthChange != 0)
{
Point? targetBefore = null;
Point? targetNow = null;
if (!lastMousePositionOnTarget.HasValue)
{
if (lastCenterPositionOnTarget.HasValue)
{
var centerOfViewport = new Point(sv.ViewportWidth / 2, sv.ViewportHeight / 2);
Point centerOfTargetNow = sv.TranslatePoint(centerOfViewport, canvas);
targetBefore = lastCenterPositionOnTarget;
targetNow = centerOfTargetNow;
}
}
else
{
targetBefore = lastMousePositionOnTarget;
targetNow = Mouse.GetPosition(canvas);
lastMousePositionOnTarget = null;
}
if (targetBefore.HasValue)
{
double dXInTargetPixels = targetNow.Value.X - targetBefore.Value.X;
double dYInTargetPixels = targetNow.Value.Y - targetBefore.Value.Y;
double multiplicatorX = e.ExtentWidth / canvas.Width;
double multiplicatorY = e.ExtentHeight / canvas.Height;
double newOffsetX = sv.HorizontalOffset - dXInTargetPixels * multiplicatorX;
double newOffsetY = sv.VerticalOffset - dYInTargetPixels * multiplicatorY;
if (double.IsNaN(newOffsetX) || double.IsNaN(newOffsetY))
{
return;
}
sv.ScrollToHorizontalOffset(newOffsetX);
sv.ScrollToVerticalOffset(newOffsetY);
}
}
}
/// <summary>
/// Scroll a ScrollViewer vertically by a given offset.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <param name="offset">The vertical offset to scroll.</param>
private static void ScrollByVerticalOffset(ScrollViewer viewer, double offset)
{
Debug.Assert(viewer != null, "viewer should not be null!");
offset += viewer.VerticalOffset;
offset = CoerceVerticalOffset(viewer, offset);
viewer.ScrollToVerticalOffset(offset);
}
/// <summary>
/// Used when virtualization is on. Moves the viewport so that HandleScrollByPage will work.
/// </summary>
private void PreScrollByPage(ScrollViewer scroller, bool up)
{
double startTop, startBottom; // offset of the top and bottom of the selected element from the top of the viewport
double adjustmentOffset = 0d; // offset we'll have to move the viewport in order to do the 'classic' page up / down algorithm
double distance = 0d; // distance from the furthest edge of either the selected item or the item we're about to select to the nearest edge of the viewport;
double viewportHeight = scroller.ViewportHeight;
_selectedContainer.GetTopAndBottom(scroller, out startTop, out startBottom);
//
// What we're doing here:
// The TreeView page down algorithm walks the tree looking for the item a page up / down from the currently selected item.
// When virtualized that algorithm breaks down since some items aren't generated.
//
// VSP maintains one page of containers above and below the viewport.
// Here we move the viewport so that the selected item or newly selected item, whichever is further,
// is only 1 page away from the top or bottom of the viewport. That allows us to use the existing
// non-virtualization algorithm.
//
if (startBottom < 0)
{
// The selected item is above the viewport; if we page up the furthest distance will be the soon-to-be selected item
distance = startBottom;
if (up)
{
distance -= viewportHeight;
}
}
else if (startTop > 0)
{
// The selected item is below the viewport; if we page down the furthest distance will be the soon-to-be selected item
distance = startTop - viewportHeight;
if (!up)
{
distance += viewportHeight;
}
}
if (Math.Abs(distance) > viewportHeight)
{
// The selected or soon-to-be selected item is more than one page away from the nearest edge of the viewport.
// Create the adjustment offset. Distance is delta between the viewport edge and the furthest item;
// we have to adjust by the viewport height to have the furthest item 1 page from the viewport
adjustmentOffset = distance < 0 ? distance + viewportHeight : distance - viewportHeight;
//
// Set the offset and update layout to ensure that all containers on the path from the selected item to the
// item we want to select are generated.
//
scroller.ScrollToVerticalOffset(scroller.VerticalOffset + adjustmentOffset);
ContextLayoutManager layoutManager = ContextLayoutManager.From(Dispatcher);
layoutManager.UpdateLayout();
}
}
private static void ScrollByVerticalOffset(ScrollViewer viewer, double offset)
{
offset += viewer.VerticalOffset;
offset = ScrollViewerExtensions.CoerceVerticalOffset(viewer, offset);
viewer.ScrollToVerticalOffset(offset);
}
/// <summary>
/// Scroll the desired element into the ScrollViewer's viewport.
/// </summary>
/// <param name="viewer">The ScrollViewer.</param>
/// <param name="element">The element to scroll into view.</param>
/// <param name="horizontalMargin">The margin to add on the left or right.
/// </param>
/// <param name="verticalMargin">The margin to add on the top or bottom.
/// </param>
/// <param name="duration">The duration of the animation.</param>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="viewer" /> is null.
/// </exception>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="element" /> is null.
/// </exception>
public static void ScrollIntoView(this ScrollViewer viewer, FrameworkElement element, double horizontalMargin, double verticalMargin, Duration duration)
{
if (viewer == null)
{
throw new ArgumentNullException("viewer");
}
else if (element == null)
{
throw new ArgumentNullException("element");
}
// Get the position of the element relative to the ScrollHost
Rect?itemRect = element.GetBoundsRelativeTo(viewer);
if (itemRect == null)
{
return;
}
// Scroll vertically
double verticalOffset = viewer.VerticalOffset;
double verticalDelta = 0;
double hostBottom = viewer.ViewportHeight;
double itemBottom = itemRect.Value.Bottom + verticalMargin;
if (hostBottom < itemBottom)
{
verticalDelta = itemBottom - hostBottom;
verticalOffset += verticalDelta;
}
double itemTop = itemRect.Value.Top - verticalMargin;
if (itemTop - verticalDelta < 0)
{
verticalOffset -= verticalDelta - itemTop;
}
// Scroll horizontally
double horizontalOffset = viewer.HorizontalOffset;
double horizontalDelta = 0;
double hostRight = viewer.ViewportWidth;
double itemRight = itemRect.Value.Right + horizontalMargin;
if (hostRight < itemRight)
{
horizontalDelta = itemRight - hostRight;
horizontalOffset += horizontalDelta;
}
double itemLeft = itemRect.Value.Left - horizontalMargin;
if (itemLeft - horizontalDelta < 0)
{
horizontalOffset -= horizontalDelta - itemLeft;
}
if (duration == TimeSpan.Zero)
{
viewer.ScrollToVerticalOffset(verticalOffset);
viewer.ScrollToHorizontalOffset(horizontalOffset);
}
else
{
Storyboard storyboard = new Storyboard();
SetVerticalOffset(viewer, viewer.VerticalOffset);
SetHorizontalOffset(viewer, viewer.HorizontalOffset);
DoubleAnimation verticalOffsetAnimation = new DoubleAnimation {
To = verticalOffset, Duration = duration
};
DoubleAnimation horizontalOffsetAnimation = new DoubleAnimation {
To = verticalOffset, Duration = duration
};
Storyboard.SetTarget(verticalOffsetAnimation, viewer);
Storyboard.SetTarget(horizontalOffsetAnimation, viewer);
Storyboard.SetTargetProperty(horizontalOffsetAnimation, new PropertyPath(ScrollViewerExtensions.HorizontalOffsetProperty));
Storyboard.SetTargetProperty(verticalOffsetAnimation, new PropertyPath(ScrollViewerExtensions.VerticalOffsetProperty));
storyboard.Children.Add(verticalOffsetAnimation);
storyboard.Children.Add(horizontalOffsetAnimation);
storyboard.Begin();
}
}
/// <summary>
/// Attempts to extract the scrollbars that are within the scrollviewers
/// visual tree. When extracted, event handlers are added to their ValueChanged events.
/// </summary>
private static void GetScrollBarsForScrollViewer(ScrollViewer scrollViewer)
{
ScrollBar scroll = GetScrollBar(scrollViewer, Orientation.Vertical);
if (scroll != null)
{
// save a reference to this scrollbar on the attached property
scrollViewer.SetValue(VerticalScrollBarProperty, scroll);
// scroll the scrollviewer
scrollViewer.ScrollToVerticalOffset(GetVerticalOffset(scrollViewer));
// handle the changed event to update the exposed VerticalOffset
scroll.ValueChanged += (s, e) => SetVerticalOffset(scrollViewer, e.NewValue);
}
scroll = GetScrollBar(scrollViewer, Orientation.Horizontal);
if (scroll != null)
{
// save a reference to this scrollbar on the attached property
scrollViewer.SetValue(HorizontalScrollBarProperty, scroll);
// scroll the scrollviewer
scrollViewer.ScrollToHorizontalOffset(GetHorizontalOffset(scrollViewer));
// handle the changed event to update the exposed HorizontalOffset
scroll.ValueChanged += (s, e) => scrollViewer.SetValue(HorizontalOffsetProperty, e.NewValue);
}
}
/// <summary>
/// Adds mouse wheel support to a <see cref="ScrollViewer"/>.
/// As long as the <see cref="ScrollViewer"/> has focus,
/// the mouse wheel can be used to scroll up and down.
/// </summary>
/// <param name="parentScrollViewer">The parent <see cref="ScrollViewer"/> which contains another <see cref="ScrollViewer" /> which should have mouse wheel scrolling support.</param>
/// <param name="childScrollViewer">A child <see cref="ScrollViewer"/> to add mouse wheel scrolling support to.</param>
/// <param name="scrollAmount">The amount to scroll by when the mouse wheel is moved.</param>
/// <returns>The child <see cref="ScrollViewer"/>.</returns>
public static ScrollViewer AddMouseWheelSupport(this ScrollViewer parentScrollViewer, ScrollViewer childScrollViewer, double scrollAmount)
{
var mouseWheelHelper = new MouseWheelSupport(childScrollViewer, parentScrollViewer);
mouseWheelHelper.MouseWheelMoved += (source, eventArgs) =>
{
var delta = eventArgs.WheelDelta;
delta *= scrollAmount;
var newOffset = childScrollViewer.VerticalOffset - delta;
if (newOffset > childScrollViewer.ScrollableHeight)
newOffset = childScrollViewer.ScrollableHeight;
else if (newOffset < 0)
newOffset = 0;
childScrollViewer.ScrollToVerticalOffset(newOffset);
eventArgs.BrowserEventHandled = true;
};
return childScrollViewer;
}
/// <summary>
/// This is the command scroll adjustment code which synchronizes two ScrollViewer instances.
/// </summary>
/// <param name="sv">ScrollViewer to adjust</param>
/// <param name="e">Change in the source</param>
/// <param name="hadjust">Horizontal adjustment</param>
/// <param name="vadjust">Vertical adjustment</param>
private static void AdjustScrollPosition(ScrollViewer sv, ScrollChangedEventArgs e, double hadjust, double vadjust)
{
if (e.HorizontalChange != 0 || e.ExtentWidthChange != 0)
{
if (e.HorizontalOffset == 0)
sv.ScrollToLeftEnd();
else if (e.HorizontalOffset >= e.ExtentWidth-5)
sv.ScrollToRightEnd();
else if (e.ExtentWidth + hadjust == sv.ExtentWidth)
sv.ScrollToHorizontalOffset(e.HorizontalOffset + hadjust);
else
sv.ScrollToHorizontalOffset((sv.ExtentWidth * (e.HorizontalOffset / e.ExtentWidth)) + hadjust);
}
if (e.VerticalChange != 0 || e.ExtentHeightChange != 0)
{
if (e.VerticalOffset == 0)
sv.ScrollToTop();
else if (e.VerticalOffset >= e.ExtentHeight-5)
sv.ScrollToBottom();
else if (e.ExtentHeight + vadjust == sv.ExtentHeight)
sv.ScrollToVerticalOffset(e.VerticalOffset + vadjust);
else
sv.ScrollToVerticalOffset((sv.ExtentHeight * (e.VerticalOffset / e.ExtentHeight)) + vadjust);
}
}
public static void AppendToActivityLog(ScrollViewer scrollViewer, TextBlock textBlock, MessageLevelsEnum level, string text)
{
if (scrollViewer.Dispatcher.CheckAccess())
{
Run activityRun = new Run();
activityRun.Text = text;
activityRun.Foreground = GetBrushForMessageLevel(level);
textBlock.Inlines.Add(activityRun);
textBlock.Inlines.Add(new LineBreak());
//scrollViewer.ScrollToVerticalOffset(scrollViewer.ScrollableHeight + 20);
scrollViewer.UpdateLayout();
scrollViewer.ScrollToVerticalOffset(Double.MaxValue);
}
else
{
scrollViewer.Dispatcher.BeginInvoke(new AppendToActivityLogDelegate(AppendToActivityLog), scrollViewer, textBlock, level, text);
}
}
private static void addToVerticalScrollGroup(string verticalGroupName, ScrollViewer scrollViewer)
{
if (verticalScrollGroups.ContainsKey(verticalGroupName))
{
scrollViewer.ScrollToVerticalOffset(verticalScrollGroups[verticalGroupName].Offset);
verticalScrollGroups[verticalGroupName].ScrollViewers.Add(scrollViewer);
}
else
{
verticalScrollGroups.Add(verticalGroupName, new OffSetContainer { ScrollViewers = new List<ScrollViewer> { scrollViewer }, Offset = scrollViewer.VerticalOffset });
}
scrollViewer.ScrollChanged += ScrollViewer_VerticalScrollChanged;
}
