怎样只捕获导航条自带的back按钮按下的事件

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self.navigationItem.hidesBackButton = YES;
UIButton* backButton = [UIButton buttonWithType:101];//UIButtonType，其实101和系统返回按钮一样
[backButton addTarget:self action:@selector(back:) forControlEvents:UIControlEventTouchUpInside];
[backButton setTitle:@"返回" forState:UIControlStateNormal];
UIBarButtonItem *leftBtn = [[[UIBarButtonItem alloc] initWithCustomView:backButton] autorelease];
self.navigationItem.leftBarButtonItem = leftBtn;

试试