改变CGRect（或任何结构体）？ [英] Alter CGRect (or any struct)?

问题描述

我在代码中做了很多：

self.sliderOne.frame  = CGRectMake(newX, 0, self.sliderOne.frame.size.width, self.sliderOne.frame.size.height); 

有没有办法避免这个繁琐的代码？我试过这样的事情：

Is there any way to avoid this tedious code? I have tried this type of thing:

self.sliderOne.frame.origin.x = newX;

但我得到一个作为分配左操作数所需的左值$ c>错误。

but I get a Lvalue required as left operand of assignment error.

推荐答案

我终于跟着@Dave DeLong的建议，并提出了一个类别。所有你需要做的是在任何想要利用它的类中导入它。

I finally followed @Dave DeLong's suggestion and made a category. All you have to do is import it in any class that wants to take advantage of it.

UIView + AlterFrame.h

#import <UIKit/UIKit.h>

@interface UIView (AlterFrame)

- (void) setFrameWidth:(CGFloat)newWidth;
- (void) setFrameHeight:(CGFloat)newHeight;
- (void) setFrameOriginX:(CGFloat)newX;
- (void) setFrameOriginY:(CGFloat)newY;

@end

UIView + AlterFrame.m

#import "UIView+AlterFrame.h"

@implementation UIView (AlterFrame)

    - (void) setFrameWidth:(CGFloat)newWidth {
        CGRect f = self.frame;
        f.size.width = newWidth;
        self.frame = f;
    }

    - (void) setFrameHeight:(CGFloat)newHeight {
        CGRect f = self.frame;
        f.size.height = newHeight;
        self.frame = f;
    }

    - (void) setFrameOriginX:(CGFloat)newX {
        CGRect f = self.frame;
        f.origin.x = newX;
        self.frame = f;
    }

    - (void) setFrameOriginY:(CGFloat)newY {
        CGRect f = self.frame;
        f.origin.y = newY;
        self.frame = f;
    }

@end

我可以把方法使用块...我会很快在某个时候做，我希望。

I could DRY up the methods using blocks... I'll do that at some point soon, I hope.

稍后：我刚刚注意到 CGRectOffset 和 CGRectInset ，所以这个类别可以被清理一下（如果没有完全消除）。

Later: I just noticed CGRectOffset and CGRectInset, so this category could be cleaned up a bit (if not eliminated altogether).

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