导航栏按钮返回

UIButton *_isussebtn;

  _isussebtn = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];

  _isussebtn.frame = CGRectMake(0, 0, 20, 20);

  [_isussebtn setImage:[UIImageimageNamed:@"Return"]forState:UIControlStateNormal];

  _isussebtn.titleLabel.font = [UIFontsystemFontOfSize:18];

  [_isussebtn addTarget:selfaction:@selector(backbtn)forControlEvents:UIControlEventTouchUpInside];

 //添加到导航条

  UIBarButtonItem *rightitem = [[UIBarButtonItemalloc]initWithCustomView:_isussebtn];

  self.navigationItem.leftBarButtonItem = rightitem;

}

@interface chatViewController ()<RCIMUserInfoDataSource,UIGestureRecognizerDelegate>

-(void)backbtn{

 //[self.navigationController dismissViewControllerAnimated:YES completion:nil];

 [self.navigationControllerpopViewControllerAnimated:YES];

}