macos 在 NSImageView 子类中未调用 mouseEntered 和 mouseExited
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mouseEntered and mouseExited not called in NSImageView SubClass
提问by Ram
I created a subclass of NSImageViewto capture mouseEnteredand mouseExitedevents.
But only mouseUpand mouseDownevents are getting called. How to capture the mouseEnteredand mouseExitedevents in NSImageViewsubclass?
我创建了一个子类NSImageView来捕获mouseEntered和mouseExited事件。但只有mouseUp和mouseDown事件被调用。如何捕获子类中的mouseEntered和mouseExited事件NSImageView？
回答by Justin Boo
If You want to use mouseEntered:and mouseExited:You need to use NSTrackingArea. Here is reference NSTrackingArea Class Reference.
如果您想使用mouseEntered:并且mouseExited:您需要使用NSTrackingArea. 这是参考NSTrackingArea 类参考。
Example:
例子：
//Add this to Your imageView subclass
-(void)mouseEntered:(NSEvent *)theEvent {
NSLog(@"Mouse entered");
}
-(void)mouseExited:(NSEvent *)theEvent
{
NSLog(@"Mouse exited");
}
-(void)updateTrackingAreas
{
[super updateTrackingAreas];
if(trackingArea != nil) {
[self removeTrackingArea:trackingArea];
[trackingArea release];
}
int opts = (NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways);
trackingArea = [ [NSTrackingArea alloc] initWithRect:[self bounds]
options:opts
owner:self
userInfo:nil];
[self addTrackingArea:trackingArea];
}
回答by Nikolay Suvandzhiev
Swift 3Version of @Justin Boo's answer:
@Justin Boo答案的Swift 3版本：
private var trackingArea: NSTrackingArea?
override func updateTrackingAreas() {
super.updateTrackingAreas()
if let trackingArea = self.trackingArea {
self.removeTrackingArea(trackingArea)
}
let options: NSTrackingAreaOptions = [.mouseEnteredAndExited, .activeAlways]
let trackingArea = NSTrackingArea(rect: self.bounds, options: options, owner: self, userInfo: nil)
self.addTrackingArea(trackingArea)
}
回答by Xenon
Swift 4 version of Justin Boo's answer
Justin Boo 答案的Swift 4 版本
override func updateTrackingAreas() {
for trackingArea in self.trackingAreas {
self.removeTrackingArea(trackingArea)
}
let options: NSTrackingArea.Options = [.mouseEnteredAndExited, .activeAlways]
let trackingArea = NSTrackingArea(rect: self.bounds, options: options, owner: self, userInfo: nil)
self.addTrackingArea(trackingArea)
}
回答by Dominique
C# Xamarin version of Justin Boo's answer
C# Xamarin 版本的 Justin Boo 的答案
public override void UpdateTrackingAreas ()
{
base.UpdateTrackingAreas ();
foreach (var item in TrackingAreas ()) {
RemoveTrackingArea (item);
}
var options = NSTrackingAreaOptions.MouseEnteredAndExited | NSTrackingAreaOptions.ActiveAlways;
var trackingArea = new NSTrackingArea (this.Bounds, options, this, null);
AddTrackingArea (trackingArea);
}
