我正在开发一个具有可拖动控件概念的项目，一切正常，除了 NSView 在调用setHidden:.
我已经能够通过将行更改session.animatesToStartingPositionsOnCancelOrFail = YES;为 NO 并使用自定义动画NSWindow子类自己实现图像快照来解决该问题。它看起来很棒，但我知道必须有更简单的方法。
我努力了：
- 在呼叫周围使用
NSAnimationContext持续时间为 0 的分组setHidden: - 使用控件和超级视图上的各种键（alpha、hidden、isHidden）设置视图动画字典
- 覆盖
animationForKey:控件及其父视图
我没有使用 CALayers，甚至尝试过明确设置wantsLayer:为 NO。
有人知道如何禁用此动画，或者有比我的动画更简单的解决方案NSWindow吗？
这是我精简后的修改代码，只看我在说什么。
@implementation NSControl (DragControl)
- (NSDraggingSession*)beginDraggingSessionWithDraggingCell:(NSActionCell <NSDraggingSource> *)cell event:(NSEvent*) theEvent
{
NSImage* image = [self imageForCell:cell];
NSDraggingItem* di = [[NSDraggingItem alloc] initWithPasteboardWriter:image];
NSRect dragFrame = [self frameForCell:cell];
dragFrame.size = image.size;
[di setDraggingFrame:dragFrame contents:image];
NSArray* items = [NSArray arrayWithObject:di];
[self setHidden:YES];
return [self beginDraggingSessionWithItems:items event:theEvent source:cell];
}
- (NSRect)frameForCell:(NSCell*)cell
{
// override in multi-cell cubclasses!
return self.bounds;
}
- (NSImage*)imageForCell:(NSCell*)cell
{
return [self imageForCell:cell highlighted:[cell isHighlighted]];
}
- (NSImage*)imageForCell:(NSCell*)cell highlighted:(BOOL) highlight
{
// override in multicell cubclasses to just get an image of the dragged cell.
// for any single cell control we can just make sure that cell is the controls cell
if (cell == self.cell || cell == nil) { // nil signifies entire control
// basically a bitmap of the control
// NOTE: the cell is irrelevant when dealing with a single cell control
BOOL isHighlighted = [cell isHighlighted];
[cell setHighlighted:highlight];
NSRect cellFrame = [self frameForCell:cell];
// We COULD just draw the cell, to an NSImage, but button cells draw their content
// in a special way that would complicate that implementation (ex text alignment).
// subclasses that have multiple cells may wish to override this to only draw the cell
NSBitmapImageRep* rep = [self bitmapImageRepForCachingDisplayInRect:cellFrame];
NSImage* image = [[NSImage alloc] initWithSize:rep.size];
[self cacheDisplayInRect:cellFrame toBitmapImageRep:rep];
[image addRepresentation:rep];
// reset the original cell state
[cell setHighlighted:isHighlighted];
return image;
}
// cell doesnt belong to this control!
return nil;
}
#pragma mark NSDraggingDestination
- (void)draggingEnded:(id < NSDraggingInfo >)sender
{
[self setHidden:NO];
}
@end
@implementation NSActionCell (DragCell)
- (void)setControlView:(NSView *)view
{
// this is a bit of a hack, but the easiest way to make the control dragging work.
// force the control to accept image drags.
// the control will forward us the drag destination events via our DragControl category
[view registerForDraggedTypes:[NSImage imagePasteboardTypes]];
[super setControlView:view];
}
- (BOOL)trackMouse:(NSEvent *)theEvent inRect:(NSRect)cellFrame ofView:(NSView *)controlView untilMouseUp:(BOOL)untilMouseUp
{
BOOL result = NO;
NSPoint currentPoint = theEvent.locationInWindow;
BOOL done = NO;
BOOL trackContinously = [self startTrackingAt:currentPoint inView:controlView];
BOOL mouseIsUp = NO;
NSEvent *event = nil;
while (!done)
{
NSPoint lastPoint = currentPoint;
event = [NSApp nextEventMatchingMask:(NSLeftMouseUpMask|NSLeftMouseDraggedMask)
untilDate:[NSDate distantFuture]
inMode:NSEventTrackingRunLoopMode
dequeue:YES];
if (event)
{
currentPoint = event.locationInWindow;
// Send continueTracking.../stopTracking...
if (trackContinously)
{
if (![self continueTracking:lastPoint
at:currentPoint
inView:controlView])
{
done = YES;
[self stopTracking:lastPoint
at:currentPoint
inView:controlView
mouseIsUp:mouseIsUp];
}
if (self.isContinuous)
{
[NSApp sendAction:self.action
to:self.target
from:controlView];
}
}
mouseIsUp = (event.type == NSLeftMouseUp);
done = done || mouseIsUp;
if (untilMouseUp)
{
result = mouseIsUp;
} else {
// Check if the mouse left our cell rect
result = NSPointInRect([controlView
convertPoint:currentPoint
fromView:nil], cellFrame);
if (!result)
done = YES;
}
if (done && result && ![self isContinuous])
[NSApp sendAction:self.action
to:self.target
from:controlView];
else {
done = YES;
result = YES;
// this bit-o-magic executes on either a drag event or immidiately following timer expiration
// this initiates the control drag event using NSDragging protocols
NSControl* cv = (NSControl*)self.controlView;
NSDraggingSession* session = [cv beginDraggingSessionWithDraggingCell:self
event:theEvent];
// Note that you will get an ugly flash effect when the image returns if this is set to yes
// you can work around it by setting NO and faking the release by animating an NSWindowSubclass with the image as the content
// create the window in the drag ended method for NSDragOperationNone
// there is [probably a better and easier way around this behavior by playing with view animation properties.
session.animatesToStartingPositionsOnCancelOrFail = YES;
}
}
}
return result;
}
#pragma mark - NSDraggingSource Methods
- (NSDragOperation)draggingSession:(NSDraggingSession *)session sourceOperationMaskForDraggingContext:(NSDraggingContext)context
{
switch(context) {
case NSDraggingContextOutsideApplication:
return NSDragOperationNone;
break;
case NSDraggingContextWithinApplication:
default:
return NSDragOperationPrivate;
break;
}
}
- (void)draggingSession:(NSDraggingSession *)session endedAtPoint:(NSPoint)screenPoint operation:(NSDragOperation)operation
{
// now tell the control view the drag ended so it can do any cleanup it needs
// this is somewhat hackish
[self.controlView draggingEnded:nil];
}
@end