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 :

#import <UIKit/UIKit.h>@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:

#import "UIView+Layout.h"​@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;