objective-c - 如何连接类？类连接到窗口

Question

下面如何使用代码来实现？类连接到窗口。

ButtonController *btn=[[ButtonController alloc]init]; 
[btnAbout.cell setTarget:btn]; 

如何实现 mouseEnter 事件？

#import "ButtonController.h"

@implementation ButtonController

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
        NSButton *button = (NSButton *)self;
        NSLog(@"%ldsss",(long)button.tag);
    }

    return self;
}

- (void)drawRect:(NSRect)dirtyRect
{
    // Drawing code here.
}
-(void)mouseEntered:(NSEvent *)theEvent{

    [self mouseEntered:theEvent];
    if (self.tag == 1) {
        NSLog(@"ee");
    }
}
@end

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#import "ButtonController.h"

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ButtonController *btnMax =[[ButtonController alloc]initWithFrame:CGRectMake(15, 0, 14, 14)];
[btnMax setImage:[NSImage imageNamed:@"max"]];
[btnMax setAlternateImage:[NSImage imageNamed:@"maxDown"]];
[[btnMax cell]setHighlightsBy:NSContentsCellMask];
[btnMax setBordered:NO];
[btnMax setTag:2];
[viewGo addSubview:btnMax];