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我想让 UISlider 响应点击minimumValueImageand/or maximumValueImage，将值设置为最小值或最大值。对于这种情况，我似乎找不到“正常”的方法，所以我想出了这个解决方案。我正在继承 UISlider 并记录用户开始触摸的位置。通过比较位置，我可以确定它是否在其中一张图像上。工作正常，但是否有一种不那么定制的方法来实现相同的目标？

@interface FGSlider ()

@property (nonatomic) CGRect minimumValueImageRect;
@property (nonatomic) CGRect maximumValueImageRect;

@property (nonatomic) BOOL touchesBeganInMinimumValueImageRect;
@property (nonatomic) BOOL touchesBeganInMaximumValueImageRect;

@end

@implementation FGSlider

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesBegan:touches withEvent:event];

    UITouch *touch = [touches anyObject];

    CGPoint location = [touch locationInView:self];
    if(CGRectContainsPoint(self.minimumValueImageRect, location)) {
        self.touchesBeganInMinimumValueImageRect = YES;
    }
    else if(CGRectContainsPoint(self.maximumValueImageRect, location)) {
        self.touchesBeganInMaximumValueImageRect = YES;
    }
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesEnded:touches withEvent:event];

    UITouch *touch = [touches anyObject];

    CGPoint location = [touch locationInView:self];
    if(self.touchesBeganInMinimumValueImageRect && CGRectContainsPoint(self.minimumValueImageRect, location)) {
        [self setValue:self.minimumValue animated:YES];
        [self sendActionsForControlEvents:UIControlEventValueChanged];
    }
    else if(self.touchesBeganInMaximumValueImageRect && CGRectContainsPoint(self.maximumValueImageRect, location)) {
        [self setValue:self.maximumValue animated:YES];
        [self sendActionsForControlEvents:UIControlEventValueChanged];
    }

    // reset state
    self.touchesBeganInMinimumValueImageRect = NO;
    self.touchesBeganInMinimumValueImageRect = NO;
}


-(CGRect)minimumValueImageRectForBounds:(CGRect)bounds {
    self.minimumValueImageRect = [super minimumValueImageRectForBounds:bounds];
    return self.minimumValueImageRect;
}

-(CGRect)maximumValueImageRectForBounds:(CGRect)bounds {
    self.maximumValueImageRect = [super maximumValueImageRectForBounds:bounds];
    return self.maximumValueImageRect;
}
@end
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1 回答 1

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我做了一个简单的类别，它似乎工作并且不依赖于计算边界并且比您的实现简单得多。试试看，让我知道你的想法。

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    for (UIView *view in self.subviews) {
        CGPoint locationPoint = [touch locationInView:view];
        if ([view pointInside:locationPoint withEvent:event]) {
            UIImageView *imageView = (UIImageView*)view;
            if (imageView.image == self.maximumValueImage) {
                [self setValue:self.maximumValue animated:YES];
                [self sendActionsForControlEvents:UIControlEventValueChanged];
            } else if (imageView.image == self.minimumValueImage) {
                [self setValue:self.minimumValue animated:YES];
                [self sendActionsForControlEvents:UIControlEventValueChanged];
            }
        }
    }
    [super touchesBegan:touches withEvent:event];
}
于 2013-07-23T21:21:14.590 回答