開發中經常會通過調節控件的frame設置控件的顯示位置，經常拿到某個控件的frame，然后修改它的屬性，比如.x .y .width .height等，修改后再賦值給控件。這樣寫沒問題，可是有沒有比較懶的方法呢，就是寫一次之后再不用重復寫了。這時候，我們應該想到分類(Catagory)

UIView+Ex.h

#import <UIKit/UIKit.h>

@interface UIView (Ex)
@property (nonatomic, assign) CGFloat x;
@property (nonatomic, assign) CGFloat y;
@property (nonatomic, assign) CGFloat width;
@property (nonatomic, assign) CGFloat height;


@end

UIView+Ex.m

#import "UIView+Ex.h"

@implementation UIView (Ex)
//重寫x屬性的 getter方法，返回控件的x值
- (CGFloat)x{
    return self.frame.origin.x;
}
//重寫x屬性的 setter方法  設置控件的x值
- (void)setX:(CGFloat)x{
    CGRect frame = self.frame;
    frame.origin.x = x;
    self.frame = frame;
}


- (CGFloat)y{
    return self.frame.origin.y;
}

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


- (CGFloat)width{
    return self.frame.size.width;
}

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

- (CGFloat)height{
    return self.frame.size.height;
}

- (void)setHeight:(CGFloat)height{
    CGRect frame = self.frame;
    frame.size.height = height;
    self.frame = frame;
}
@end

UIViewController類導入分類后，UIView極其子類(如UIButton)就可以直接.x .y .width .height調整坐標了。