MacOS 开发 -NSView添加鼠标监控

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

• 如果NSView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。

代码示例如下

- (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];
    
}

3、实现监控方法

在MSView.m中写下下列方法

//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 ======= ");
}

• NSView无法调用keyDown、keyUp，他们用于输入类，如NSTextField。

代码调用如下：

//
//  ViewController.m
//  HelloMacOS
//
//  Created by xiezw on 2019/8/1.
//  Copyright © 2019 xiezw. All rights reserved.
//

#import "ViewController.h"
#import "MSView.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    // Do any additional setup after loading the view.
    MSView * view = [[MSView 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

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