快速修改frame

快速修改UIView的frame

本篇是本人写的第一篇博客, 博客内容借鉴了简书(@sunljz)的文章, 写博客的目的是整理自己学习的内容, 同时也锻炼自己.

UIView的frame是我们开发中最熟悉不过的属性之一了, 而我们在开发过程中经常需要对设置好的frame进行改变. 但是修改frame非常麻烦, frame是CGRect类型的, 而CGRect是结构体, 结构体类型里是不允许修改单个属性的, 那么我们想修改frame的属性的话, 需要三个步骤, 1.先把frame取出来 2.修改frame 3.重新赋值回去.

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(50, 50, 100, 100)];
  CGRect frame = view.frame;
  frame.size.width += 50;
  view.frame = frame;

如果frame的单个属性可以直接修改, 那么使用起来会很方便, 代码看起来也很整洁.其实这时我们给UIView加个类别就可以达到这种效果了.
在类别中声明属性 :

@interface UIView (Layout)
​
@property (nonatomic, assign) CGFloat top;         /< 上方位置 */
@property (nonatomic, assign) CGFloat bottom;       /< 底部位置 */
@property (nonatomic, assign) CGFloat left;         /< 左边位置 */
@property (nonatomic, assign) CGFloat right;       /< 右边位置 */
​
@property (nonatomic, assign) CGFloat x;           /< x坐标 */
@property (nonatomic, assign) CGFloat y;           /< y坐标 */
@property (nonatomic, assign) CGPoint origin;       /< 起始点 */
​
@property (nonatomic, assign) CGFloat centerX;     /< X的中心位置 */
@property (nonatomic, assign) CGFloat centerY;     /< Y的中心位置 */
​
@property (nonatomic, assign) CGFloat width;       /< 宽度 */
@property (nonatomic, assign) CGFloat height;       /< 高度 */
@property (nonatomic, assign) CGSize size;         /< 大小 */
​
​
@end

然后在.m中重写它们的getter和setter方法:

@implementation UIView (Layout)
​
@dynamic top;
@dynamic bottom;
@dynamic left;
@dynamic right;
​
@dynamic x;
@dynamic y;
​
@dynamic width;
@dynamic height;
​
@dynamic size;
​

• (void)setTop:(CGFloat)top{
  ​
    CGRect frame = self.frame;
    frame.origin.y = top;
    self.frame = frame;
  }
• (CGFloat)top{
  ​
    return self.frame.origin.y;
  }
  ​
• (void)setBottom:(CGFloat)bottom{
  ​
    CGRect frame = self.frame;
    frame.origin.y = bottom - frame.size.height;
    self.frame = frame;
  }
• (CGFloat)bottom{
  ​
    return self.frame.origin.y + self.frame.size.height;
  }
  ​
• (void)setLeft:(CGFloat)left{
  ​
    CGRect frame = self.frame;
    frame.origin.x = left;
    self.frame = frame;
  ​
  }
• (CGFloat)left{
  ​
    return self.origin.x;
  }
  ​
• (void)setRight:(CGFloat)right{
  ​
    CGRect frame = self.frame;
    frame.origin.x = right - self.frame.size.width;
    self.frame = frame;
  }
• (CGFloat)right{
  ​
    return self.frame.size.width + self.frame.origin.x;
  }
  ​
• (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)setCenterX:(CGFloat)centerX{
  ​
    CGPoint center = self.center;
    center.x = centerX;
    self.center = center;
  }
• (CGFloat)centerX{
  ​
    return self.center.x;
  }
  ​
• (void)setCenterY:(CGFloat)centerY{
  ​
    CGPoint center = self.center;
    center.y = centerY;
    self.center = center;
  }
• (CGFloat)centerY{
  ​
    return self.center.y;
  }
  ​
• (void)setOrigin:(CGPoint)origin{
  ​
    CGRect frame = self.frame;
    frame.origin = origin;
    self.frame = frame;
  }
• (CGPoint)origin{
  ​
    return self.frame.origin;
  }
  ​
• (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;
  }
  ​
  @end

在我们需要的时候只要包含头文件 :

import "UIView+Layout.h"

就可以轻松的修改frame单个的属性了 :

view.height = 200;
view.x = 100;