Question

我想通过代码设置UIButton的标题。我发现自己不得不为UIControlStateNormal，UIControlStateHighlighted，UIControlStateDisabled，UIControlStateSelected调用 - [UIButton setTitle：forState：]。而且这甚至没有考虑到这些状态的所有组合。

毋庸置疑，这很无聊。我可以进行一次调用，将一个字符串设置为所有状态的标题吗？（因为，我认为在95％的情况下，这是理想的行为？）

Answer 1

是的，你当然可以。 From the docs：

一般情况下，如果属性不是为状态指定，默认为使用UIControlStateNormal值。如果UIControlStateNormal的值未设置，则属性默认到系统值。因此，在最小值，你应该设置值正常状态。

所以只需设置UIControlStateNormal的标题，你就是黄金。

Answer 2

像先生/麦斯先生一样。 Frog说，设置UIControlStateNormal的标题通常会起作用。唯一的例外是如果已经为其他州设置了标题。 UIControlState是一个掩码，所以你可以这样覆盖你的屁股：

[button setTitle:@"Title" forState:UIControlStateNormal|UIControlStateHighlighted| UIControlStateDisabled|UIControlStateSelected]

如果你想简明扼要：

#define kAllControlStates (UIControlStateNormal|UIControlStateHighlighted| UIControlStateDisabled|UIControlStateSelected)
[button setTitle:@"Title" forState:kAllControlStates];

简洁而不透明：

[button setTitle:@"Title" forState:0xffff];

更新：我应该在回答之前对此进行测试。事实证明，像UIControlStateHighlighted|UIControlStateDisabled这样的掩码表示控件突出显示和时的状态。我错误地认为该掩码表示“高亮或已禁用”。总而言之，你最好先了解Frog先生的答案。

Answer 3

为UIButton创建一个类别方法，一次为所有状态设置它。

Answer 4

尽管99％的时间都回到了UIControlStateNormal状态的值可能已经足够好了，但我已经为1％的用例提出了解决这个问题的方法。（我在子类中有应用程序定义的状态，这意味着回退到正常状态是不正确的。）

我在这里发布它是为了完整性，即使答案已被接受。基本上它设置状态的属性加上您指定的各个附加状态的每个组合。

@interface UIButton (AdditionalStates)
- (void)setTitle:(NSString *)title forState:(UIControlState)state additionalStates:(UIControlState)additionalStates;
@end

@implementation UIButton (AdditionalStates)

- (void)setTitle:(NSString *)title forState:(UIControlState)state additionalStates:(UIControlState)additionalStates
{
    [self setValue:title forKey:@"title" state:state additionalStates:additionalStates mask:(1 << 0)];
}

- (void)setValue:(id)value forKey:(NSString *)key state:(UIControlState)state additionalStates:(UIControlState)additionalStates mask:(NSUInteger)mask(UIControlState)additionalStates
{
    if (additionalStates == 0) {
        [self setValue:value forKey:key state:state];
        return;
    }

    // Iterate over each 'on' bit in additionalStates, starting from the mask bit
    while (mask > 0) {
        if (additionalStates & mask) {
            // Delete the current bit from additionalStates
            NSUInteger reducedAdditionalStates = (additionalStates ^ mask);

            // Set the title for combinations of the remaining additional states with and without the mask bit
            [self setValue:value forKey:key state:(state | (additionalStates & mask)) additionalStates:reducedAdditionalStates mask:(mask << 1)];
            [self setValue:value forKey:key state:state additionalStates:reducedAdditionalStates mask:(mask << 1)];
        }
        mask = (mask << 1);
    }
}

- (void)setValue:(id)value forKey:(NSString *)key state:(UIControlState)state
{
    if ([key isEqualToString:@"title"]) {
        [self setTitle:value forState:state];
        return;
    }
}

@end

使用单个方法调用设置UIButton的标题？

4 个答案: