objective-c – 核心情节mouseMoved

概述当鼠标移动/悬停在符号或线上时,我想在 scatterplot中显示(注释)值.我之前已经问过这个问题,但我只能找到需要用户点击图表来显示此信息的答案.我试图在plotView委托中实现mouseMoved方法： - (void)mouseMoved:(NSEvent *)theEvent{ NSPoint location = [hostingView convertPoint: [t 当鼠标移动/悬停在符号或线上时,我想在 scatterplot中显示(注释)值.我之前已经问过这个问题,但我只能找到需要用户点击图表来显示此信息的答案.我试图在plotVIEw委托中实现mouseMoved方法：

- (voID)mouseMoved:(NSEvent *)theEvent{    NSPoint location = [hostingVIEw convertPoint: [theEvent locationInWindow] fromVIEw: nil];    CGPoint mouseLocation = NSPointTocgPoint(location);    CGPoint pointInHostedGraph = [hostingVIEw.layer convertPoint: mouseLocation tolayer:  plotItem.graph.plotAreaFrame.plotArea];    NSUInteger index = [self.plotItem.dataSourcelinePlot indexOfVisiblePointClosesttoplotAreaPoint: pointInHostedGraph];    NSLog(@"test: %lu",(unsigned long)index);

}

这里,plotItem是NSObject的子类,在example中定义为PlotItem.h,托管视图是CPTGraphHostingVIEw的一个实例.我还补充说：

CPTGraphHostingVIEw *hostedlayer=[self.plotItem updateVIEw:hostingVIEw height:hostingVIEw.frame.size.height wIDth:hostingVIEw.frame.size.wIDth];    [self.plotItem renderInVIEw:hostedlayer withtheme:theme animated:YES withData:self.myFlattenednodes];    hostedlayer.window.acceptsMouseMovedEvents = YES;    [hostedlayer.window makeFirstResponder:hostingVIEw];

但是我的mouseMoved方法没有被调用.我在这里做错了什么,因为我无法让mouseMoved响应我的悬停.我是否需要将NSTrackingArea添加到hostedLayer？建议表示赞赏. Ť

更新和解决方案：
我遵循了Erics的建议,并将我的CPTGraphHostingVIEw子类化,我实现了以下内容：

- (ID)initWithFrame:(NSRect)frame{    self = [super initWithFrame:frame];    if (self) {        self.window.acceptsMouseMovedEvents = YES;        [self.window makeFirstResponder:self];        area = [[NSTrackingArea alloc] initWithRect:self.frame                                            options: (NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved | NSTrackingActiveInKeyWindow| NSTrackingActiveAlways)                                              owner:self userInfo:nil];        [self addTrackingArea:area];        [self becomeFirstResponder];    }    return self;}- (voID)updateTrackingAreas {    [self removeTrackingArea:area];    area = [[NSTrackingArea alloc] initWithRect:self.frame                                    options: (NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved | NSTrackingActiveInKeyWindow| NSTrackingActiveAlways)                                      owner:self userInfo:nil];    [self addTrackingArea:area];}- (voID)mouseMoved:(NSEvent *)theEvent{    NSPoint location = [self convertPoint: [theEvent locationInWindow] fromVIEw: nil];    CGPoint mouseLocation = NSPointTocgPoint(location);    [self setLocationOfMouse:[self.layer convertPoint: mouseLocation tolayer:nil]];}-(voID) dealloc{    [self removeTrackingArea:area];}

我还定义了类的属性：

CGPoint locationOfMouse;NSTrackingArea *area;

在我的控制器中,我为locationOfMouse属性添加了一个观察者：

[self.plotItem.graphHostingVIEw addobserver:self                        forKeyPath:@"locationOfMouse"                           options:0                           context:NulL];

这触发了我绘制注释的方法：

-(voID)observeValueForKeyPath:(Nsstring *)keyPath ofObject:(ID)object change:(NSDictionary *)change context:(voID *)context{     if ( [keyPath isEqualToString:@"locationOfMouse"] ) {        CGPoint location = self.plotItem.graphHostingVIEw.locationOfMouse;        [self.plotItem mouseMovedOvergraph:location];        }    else {        [super observeValueForKeyPath:keyPath ofObject:object                           change:change context:context];    }}

解决方法 Core Plot不会将鼠标移动的事件传递给任何代理.子类CPTGraphHostingVIEw(它是NSVIEw的子类)并在那里实现-mouseMoved：方法. Core Plot仅使用鼠标按下,拖动和向上事件,因此您不会干扰任何内置事件处理. 总结

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