NSTrackingArea工作奇怪 - 整个视图，或没有什么...没有矩形尊重

问题描述

在视图的InitWithFrame方法中，我设置了一个要捕获鼠标进入/退出事件的跟踪区域。

我的问题有两个：

In my "InitWithFrame" method of a view I'm setting a tracking area for which I want to capture mouse enter/exit events.
My problems are two fold:

1. 如果没有NSTrackingInVisibleRect，事件将不会被调用。


2. 无论使用什么rect覆盖整个视图的框架或仅占据其一小部分的框架 - 无论鼠标光标在视图上的位置，都为整个视图调用鼠标进入/退出事件。

这是我如何初始化跟踪区域：

this is how I initialize the tracking area:

trackingArea = [[NSTrackingArea alloc] initWithRect:rect
  options: (NSTrackingMouseEnteredAndExited | NSTrackingInVisibleRect | NSTrackingActiveAlways )
  owner:self userInfo:nil];
[self addTrackingArea:trackingArea];

任何线索为什么会发生这种情况？

Any clues why this happens? I want the mouse enter/exit events to be called only for a small portion (the bottom part) of my view.

推荐答案

我想要鼠标进入/退出事件只对我的视图的一小部分

Mike Abdullah's answer explains point 2.

这里是一个猜测，为什么不使用NSTrackingInVisibleRect标志时根本没有收到事件：

可能您提供的变量 rect 不在视图的坐标系内。您可以使用以下代码作为NSView子类的指定初始化程序，以接收 mouseEntered：和 mouseExited：

Here is a guess about why you don't receive events at all when not using the NSTrackingInVisibleRect flag:
Probably the variable rect you provide is not within the view's coordinate system. You could use the following code as the designated initializer of your NSView subclass to receive mouseEntered: and mouseExited: events for the whole area of your view:

- (id)initWithFrame:(NSRect)frame 
{
    if ((self = [super initWithFrame:frame])) 
    {
        //by using [self bounds] we get our internal origin (0, 0)
        NSTrackingArea* trackingArea = [[NSTrackingArea alloc] initWithRect:[self bounds] options:(NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways) owner:self userInfo:nil];
        [self addTrackingArea:trackingArea];
        [trackingArea release];
    }
    return self;
}

Apple的说：

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