Foundouction框架里的frame屬性是CGRect類型，CGRect是結構體，結構體類型里面的某個屬性想修改是不能直接修改的，必須先取出來然后再重新賦值回去，完成三部曲，著實麻煩，確切的說一般是不能直接修改“對象的 結構體屬性的 成員”，但能夠修改“對象的 結構體屬性”。

所以，解決方案，一般是把原有對象的結構體屬性賦值給一個臨時結構體，然后對臨時結構體里地成員進行修改，然后把這個修改好的結構體變量直接賦值給原有對象的結構體變量，相當于修改了

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

category分類
UIView 多增加幾個屬性x，y，height，width。這幾個屬性都分別實現get方法和set方法。這樣以后frame就可以離開他了，這樣導入分類的所有繼承UIView的類都有了這幾個屬性，可以直接對其尺寸和坐標賦值，不用引入中間變量，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