ios中多个按钮只能选中一个

 //_normalarray = @[@"like",@"More",@"Reply",@"share"];

 _normalarray = [NSArray arrayWithObjects:@"脑炎后遗症",@"More",@"Reply",@"share", nil];

 _selectedarray = @[@"矮小症",@"矮小症",@"矮小症",@"矮小症"];

 for (int i = 0; i < 4; i++) {

  _btntwo = [[UIButton alloc]initWithFrame:CGRectMake( i *(80 +2), 100, 120, 120)];

  _btntwo.backgroundColor = [UIColor redColor];

  [_btntwo addTarget:self action:@selector(clickbtntwo:) forControlEvents:UIControlEventTouchUpInside];

  [_btntwo setBackgroundImage:[UIImage imageNamed:_normalarray[i]] forState:UIControlStateNormal];

  _btntwo.tag = i+100;

  _btntwo.selected = NO;

  _btntwo.layer.cornerRadius = 60;

  _btntwo.layer.masksToBounds = YES;

  [_btntwo setBackgroundImage:[UIImage imageNamed:_selectedarray[i]] forState:UIControlStateSelected];

  [self.view addSubview:_btntwo];

 }

}

-(void)clickbtntwo:(UIButton *)sender{

 for (int i = 0; i < _normalarray.count; i++) {

  UIButton *btn = (UIButton *)[[sender superview]viewWithTag:100 + i];

  [btn setSelected:NO];

 }

 UIButton *button = (UIButton *)sender;

 [button setSelected:YES];

}