一、鼠标点击事件响应流程简述：

1.鼠标硬件先接收到用户点击；
2.然后交给鼠标驱动来处理，这个驱动是在Mac OS X内核运行的；
3.处理完就通过I/O Kit传递给window sever的事件队列。
4.而window server则负责分派这些事件到对应进程的run-loop.

二、步骤

1.自定义VC1 继承自NSView ;
2.在VC1.m的drawRect方法中添加监控区域NSTrackingArea和监控样式

• 如果VC1不添加NSTrackingArea,即使实现了监控方法，也不会调用。
• 监控区域要使用dirtyRect,而非self.frame,否则位置会错误。

#import "ViewController.h"

#import "VC1.h"

@interface ViewController ()

@end

@implementation ViewController

-(void)viewDidLoad {

    [super viewDidLoad];

   VC1 * view = [[VC1 alloc] initWithFrame:NSMakeRect(100, 100, 300, 300)];

   [view setWantsLayer:YES];//开启layer支持,不然设置背景色无用

   view.layer.backgroundColor = [NSColor blueColor].CGColor;

   [self.view addSubview:view];

}

- (void)setRepresentedObject:(id)representedObject {

    [super setRepresentedObject:representedObject];

    // Update the view, if already loaded.

}

@end

#import <Cocoa/Cocoa.h>

NS_ASSUME_NONNULL_BEGIN

@interface VC1 : NSView

@end

NS_ASSUME_NONNULL_END

#import "VC1.h"

@interface VC1 ()

@end

@implementation VC1

//鼠标进入追踪区域

-(void)mouseEntered:(NSEvent *)event {

    NSLog(@"mouseEntered =========");

}

//mouserEntered之后调用

-(void)cursorUpdate:(NSEvent *)event {

    NSLog(@"cursorUpdate ==========");

    //更改鼠标光标样式

    [[NSCursor pointingHandCursor] set];

}

//鼠标退出追踪区域

-(void)mouseExited:(NSEvent *)event {

    NSLog(@"mouseExited ========");

}

//鼠标左键按下

-(void)mouseDown:(NSEvent *)event {

    //event.clickCount 不是累计数。双击时调用mouseDown两次，clickCount第一次=1，第二次 = 2.

    if ([event clickCount] > 1) {

        //双击相关处理

    }

    NSLog(@"mouseDown ==== clickCount: %ld  buttonNumber: %ld",event.clickCount,event.buttonNumber);

    self.layer.backgroundColor = [NSColor redColor].CGColor;

    //获取鼠标点击位置坐标：先获取event发生的window中的坐标，在转换成view视图坐标系坐标。

    NSPoint eventLocation = [event locationInWindow];

    NSPoint center = [self convertPoint:eventLocation fromView:nil];

    NSLog(@"center: %@",NSStringFromPoint(center));

    //判断是否按下了Command键

    if ([event modifierFlags] & NSEventModifierFlagCommand) {

        [self setFrameRotation:[self frameRotation] + 90.0];

        [self setNeedsDisplay:YES];

        NSLog(@"按下了Command键 ---- ");

    }

}

//鼠标左键起来

-(void)mouseUp:(NSEvent *)event {

    NSLog(@"mouseUp ======");

    self.layer.backgroundColor = [NSColor greenColor].CGColor;

}

//鼠标右键按下

- (void)rightMouseDown:(NSEvent *)event {

    NSLog(@"rightMouseDown =======");

}

//鼠标右键起来

- (void)rightMouseUp:(NSEvent *)event {

    NSLog(@"rightMouseUp ======= ");

}

//鼠标移动

- (void)mouseMoved:(NSEvent *)event {

    NSLog(@"mouseMoved ========= ");

}

//鼠标按住左键进行拖拽

- (void)mouseDragged:(NSEvent *)event {

    NSLog(@"mouseDragged ======== ");

}

//鼠标按住右键进行拖拽

- (void)rightMouseDragged:(NSEvent *)event {

    NSLog(@"rightMouseDragged ======= ");

}

#pragma mark 监控区域要使用dirtyRect,而非self.frame,否则位置会错误。

- (void)drawRect:(NSRect)dirtyRect {

    [super drawRect:dirtyRect];

    // Drawing code here.

    [self addTrackingArea:[[NSTrackingArea alloc] initWithRect:dirtyRect options:NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved |

                           NSTrackingCursorUpdate |

                           NSTrackingActiveWhenFirstResponder |

                           NSTrackingActiveInKeyWindow |

                           NSTrackingActiveInActiveApp |

                           NSTrackingActiveAlways |

                           NSTrackingAssumeInside |

                           NSTrackingInVisibleRect |

                           NSTrackingEnabledDuringMouseDrag

                        owner:self userInfo:nil]];

    [self becomeFirstResponder];

}

@end