将操作的目标设置为NSObject

Question

我想将动作的目标设置为创建它的类。但是，当我尝试app crashes时。

Test.h：

#import <Foundation/Foundation.h>

@class Test;
@protocol TestDelegate<NSObject>
@end

@interface Test : NSObject
{
    UIView *theView;
}
@property (assign) id<TestDelegate> delegate;
- (id)initWithView:(UIView *)view;
@end

Test.m：

#import "Test.h"

@implementation Test

- (id)initWithView:(UIView *)view
{
    if (self=[super init]) {
        theView = view;
        int size = 60;

        UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        [button addTarget:self
               action:@selector(buttonAction:)
     forControlEvents:UIControlEventTouchDown];
        [button setTitle:@"button" forState:UIControlStateNormal];
        button.frame = CGRectMake(view.frame.size.width/2 - size, view.frame.size.height/2 - size, size, size);
        [view addSubview:button];    
    }
    return self;
}

- (void)buttonAction:(UIButton *)sender
{
     theView.backgroundColor = [UIColor blueColor];
}
@end

错误：

EXC_BAD_ACCESS (code=1,address=0x0)

argv    char ** 0x27db7d04  0x27db7d04

*argv   char *  "/var/mobile/Applications/EC1DE795-A5B7-4E8F-AC3D-E42551D1B284/appName.app/appName" 0x27db7da8

**argv  char    '/' '/'

argc    int 1   1