ios中UIButton选中状态切换

关于UIButton的事件枚举有许多，平时用的少所以很多的都不是很清楚，今天了解了下，看了以前的代码，觉得在UIButton选中时操作写了许多冗余代码，而忽略了UIButton一个很重要的属性，如下：

typedef NS_OPTIONS(NSUInteger, UIControlState) {
    UIControlStateNormal       = 0,
    UIControlStateHighlighted  = 1 << 0,                  // used when UIControl isHighlighted is set
    UIControlStateDisabled     = 1 << 1,
    UIControlStateSelected     = 1 << 2,                  // flag usable by app (see below)
#ifndef SDK_HIDE_TIDE
    UIControlStateFocused NS_ENUM_AVAILABLE_IOS(9_0) = 1 << 3, // Applicable only when the screen supports focus
#endif
    UIControlStateApplication  = 0x00FF0000,              // additional flags available for application use
    UIControlStateReserved     = 0xFF000000               // flags reserved for internal framework use
};

中的UIControlStateSelected表示是否选中，NO表示未选中，YES表示选中；

1.这是之前写的：

创建UIButton，通过for 循环去创建

//顶部view的初始化
- (void)initTopView{

    topView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, kScreen_width, 40)];
    topFrame = topView.frame;
    topView.backgroundColor = [UIColor whiteColor];
    topView.alpha = .8;

    NSArray *titleArr = @[@"人气",@"价格",@"桌数",@"优惠"];
    for (int i = 0; i < titleArr.count; i ++) {
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
        [btn setTitle:titleArr[i] forState:UIControlStateNormal];
        [btn setImage:[UIImage imageNamed:@"ph"] forState:UIControlStateNormal];
        [btn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
        [btn setBackgroundImage:[UIImage imageNamed:@"button1"] forState:UIControlStateNormal];
        btn.titleLabel.font = [UIFont systemFontOfSize:12];
        btn.showsTouchWhenHighlighted = YES;
        btn.frame = CGRectMake(10 + i * ((kScreen_width - 50)/4 + 10) , 10, (kScreen_width - 50)/4, 25);
        //设置tag值
        btn.tag = i + 100;
        [btn addTarget:self action:@selector(choose:) forControlEvents:UIControlEventTouchUpInside];
        [topView addSubview:btn];
    }

    [self.view addSubview:topView];
}

添加响应事件：

//人气、价格、作品数、优惠
- (void)choose:(UIButton *)sender{
    for (int i = 0; i < 4; i++) {
        UIButton *btn = (UIButton *)[[sender superview]viewWithTag:100 + i];
        [btn setSelected:NO];
        if (!btn.selected) {
            [btn setImage:[UIImage imageNamed:@"ph"] forState:UIControlStateNormal];
            [btn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
            [btn setBackgroundImage:[UIImage imageNamed:@"button1"] forState:UIControlStateNormal];
        }
    }
    UIButton *button = (UIButton *)sender;
    [button setSelected:YES];
    [button setImage:[UIImage imageNamed:@"pho"] forState:UIControlStateNormal];
    [button setTitleColor:[UIColor colorWithRed:170.0/255 green:107.0/255 blue:208.0/255 alpha:1] forState:UIControlStateNormal];
    [button setBackgroundImage:[UIImage imageNamed:@"button2"] forState:UIControlStateNormal];
}

这种是最简单的，相对也是最繁琐的，多了很多不必要的冗余代码，下面就让我们看看改进的；

2.通过使用UIButton自己的一个selected属性和normal属性重构的，如下所示：

-(void)initUIButtonView{

    _titleArr = @[@"人气",@"价格",@"桌数",@"优惠"];

    for (int i = 0; i < _titleArr.count; i ++) {
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
        btn.frame = CGRectMake(10 + i * ((kScreen_width - 50)/4 + 10) , 20, (kScreen_width - 50)/4, 25);
        [btn setTitle:_titleArr[i] forState:UIControlStateNormal];
        btn.titleLabel.font = [UIFont systemFontOfSize:12];
        btn.showsTouchWhenHighlighted = YES;
        //设置tag值
        btn.tag = i + 100;
        btn.selected = NO;
        [btn addTarget:self action:@selector(choose:) forControlEvents:UIControlEventTouchUpInside];
        [btn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
        [btn setImage:[UIImage imageNamed:@"ph"] forState:UIControlStateNormal];
        [btn setBackgroundImage:[UIImage imageNamed:@"button1"] forState:UIControlStateNormal];

        [btn setTitleColor:[UIColor colorWithRed:170.0/255 green:107.0/255 blue:208.0/255 alpha:1] forState:UIControlStateSelected];
        [btn setImage:[UIImage imageNamed:@"pho"] forState:UIControlStateSelected];
        [btn setBackgroundImage:[UIImage imageNamed:@"button2"] forState:UIControlStateSelected];
        [self.view addSubview:btn];
    }

}

在创建的时候就给定了正常时候UIButton的样式，和选中UIButton时的按钮颜色，注意这里设置了默认的selected ＝ NO；和UIControlStateSelected

在给定按钮选择事件，设置对应selected的状态值，如下所示：

//人气、价格、作品数、优惠
- (void)choose:(UIButton *)sender{
    for (int i = 0; i < _titleArr.count; i++) {
        UIButton *btn = (UIButton *)[[sender superview]viewWithTag:100 + i];
        [btn setSelected:NO];
    }
    UIButton *button = (UIButton *)sender;
    [button setSelected:YES];
}

这样看上去，第二种方法，是不是比第一种方法更简单明了，去除了相关的冗余代码的，效果如下所示

注：改进，上面的我们可以在不同的按钮上面切换状态，但在同一个按钮上面点击多次状态不会改变，针对上述问题做了些许的改动，其实主要是在点击事件里面，判断当前按钮的状态去改变，代码如下：

//人气、价格、作品数、优惠
- (void)choose:(UIButton *)sender{
    for (int i = 0; i < _titleArr.count; i++) {
        UIButton *btn = (UIButton *)[[sender superview]viewWithTag:100 + i];
        //选中当前按钮时
        if (sender.tag == btn.tag) {

            sender.selected = !sender.selected;
        }else{

            [btn setSelected:NO];
        }
    }

}

效果图如下所示：