一.简介

NSImageView和iOS的UIImageView类似，只有添加手势时有些不一样。macOS中NSImageView没有userInteractionEnabled,不能添加gesture。

二.示例

要想给NSImageView添加手势有2种方式

• 需要创建一个子类集成NSImageView，重写mouseDown、mouseUp等方法。

  //  FSImageView.h
  #import <Cocoa/Cocoa.h>
  
  @interface FSImageView : NSImageView
  
  @property (copy, nonatomic) void(^mouseDownBlock)(void);
  @property (copy, nonatomic) void(^mouseUpBlock)(void);
  
  @end
  
  //  FSImageView.m
  #import "FSImageView.h"
  
  @implementation FSImageView
  
  - (void)drawRect:(NSRect)dirtyRect {
      [super drawRect:dirtyRect];
      
      // Drawing code here.
  }
  
  - (void)mouseDown:(NSEvent *)event {
      if (self.mouseDownBlock) {
          self.mouseDownBlock();
      }
  }
  
  - (void)mouseUp:(NSEvent *)event {
      if (self.mouseUpBlock) {
          self.mouseUpBlock();
      }
  }
  
  @end
   
  //  ViewController.m
  FSImageView *imgView = [[FSImageView alloc] initWithFrame:CGRectMake(10, 10, 200, 200)];
  imgView.image = [NSImage imageNamed:@"avator"];
  // 设置背景色
  imgView.wantsLayer = YES;
  imgView.layer.backgroundColor = NSColor.redColor.CGColor;
  
  // 设置圆角
  imgView.layer.cornerRadius = 100;
  // 设置边框
  imgView.layer.borderColor = NSColor.redColor.CGColor;
  imgView.layer.borderWidth = 5;
  
  // 添加手势
  imgView.mouseDownBlock = ^{
    // 按下
  };
  imgView.mouseUpBlock = ^{
    // 抬起
  };
  
  [self.view addSubview:imgView];
  

• 为NSImageView添加手势NSGestureRecognizer

  // NSGestureRecognizer的子类来确定使用哪种手势
  /*! 
  NSClickGestureRecognizer                  单点
  NSPanGestureRecognizer                        拖动
  NSMagnificationGestureRecognizer  放大
  NSPressGestureRecognizer                  按压
  NSRotationGestureRecognizer               旋转
  */
  FSImageView *imgView = [[FSImageView alloc] initWithFrame:CGRectMake(10, 10, 200, 200)];
  imgView.image = [NSImage imageNamed:@"avator"];
  // 设置背景色
  imgView.wantsLayer = YES;
  imgView.layer.backgroundColor = NSColor.redColor.CGColor;
  // 设置圆角
  imgView.layer.cornerRadius = 100;
  // 设置边框
  imgView.layer.borderColor = NSColor.redColor.CGColor;
  imgView.layer.borderWidth = 5;
  // 添加手势
  NSClickGestureRecognizer *gesture = [[NSClickGestureRecognizer alloc] initWithTarget:self action:@selector(imageViewClick:)];
  [view addGestureRecognizer:gesture];
  [self.view addSubview:imgView];
  
  - (void)imageViewClick:(NSGestureRecognizer *)gesture {
      NSLog(@"touch view");
  }