Foundouction框架里的frame属性是CGRect类型，CGRect是结构体，结构体类型里面的某个属性想修改是不能直接修改的，必须先取出来然后再重新赋值回去，完成三部曲，着实麻烦，确切的说一般是不能直接修改“对象的 结构体属性的 成员”，但能够修改“对象的 结构体属性”。

所以，解决方案，一般是把原有对象的结构体属性赋值给一个临时结构体，然后对临时结构体里地成员进行修改，然后把这个修改好的结构体变量直接赋值给原有对象的结构体变量，相当于修改了

UIView * view = [[UIView alloc]init];
view.frame.origin.x = 100;
CGRect frame = view.frame;
frame.origin.x = 100;
view.frame = frame;

category分类
UIView 多增加几个属性x，y，height，width。这几个属性都分别实现get方法和set方法。这样以后frame就可以离开他了，这样导入分类的所有继承UIView的类都有了这几个属性，可以直接对其尺寸和坐标赋值，不用引入中间变量，快捷方便

• UIView+WKCategory.h

  #import <UIKit/UIKit.h>
   @interface UIView (WKCategory)
   @property (assign, nonatomic) CGFloat x;
   @property (assign, nonatomic) CGFloat y;
   @property (assign, nonatomic) CGFloat width;
   @property (assign, nonatomic) CGFloat height;
   @property (assign, nonatomic) CGSize size;
   @property (assign, nonatomic) CGPoint origin;
   @end
  

• UIView+WKCategory.m
  #import "UIView+WKCategory.h"

    @implementation UIView (WKCategory)
  
      -(void)setX:(CGFloat)x{
            CGRect frame = self.frame;
           frame.origin.x = x;
          self.frame = frame;
       }
  
     - (CGFloat)x
       {
         return self.frame.origin.x;
         }
  
      -(void)setY:(CGFloat)y
         {
        CGRect frame = self.frame;
         frame.origin.y = y;
        self.frame = frame;
         }
  
     - (CGFloat)y
       {
        return self.frame.origin.y;
        }
  
    -(void)setWidth:(CGFloat)width{
        CGRect frame = self.frame;
        frame.size.width = width;
        self.frame = frame;
       }
  
    - (CGFloat)width
        {
        return self.frame.size.width;
        }
  
      - (void)setHeight:(CGFloat)height
         {
          CGRect frame = self.frame;
          frame.size.height = height;
          self.frame = frame;
         }
  
      - (CGFloat)height
         {
         return self.frame.size.height;
         }
  
      - (void)setSize:(CGSize)size
          {
            CGRect frame = self.frame;
             frame.size = size;
            self.frame = frame;
           }
  
      - (CGSize)size
      {
        return self.frame.size;
      }
  
     - (void)setOrigin:(CGPoint)origin
         {
        CGRect frame = self.frame;
          frame.origin = origin;
         self.frame = frame;
        }
  
       - (CGPoint)origin
       {
        return self.frame.origin;
        }
  
        @end