iOS开发-快速修改UIView的frame方法

在iOS中，通常修改UIView.frame中的某一个值是非常痛苦的，因为Size和Origin都是readonly的，所以每次都需要进行如下繁琐的书写：

view.frame = CGRectMake(view.frame.origin.x, 100, view.frame.size.width, view.frame.size.height);

这种写法在UI较多的界面中，写的人非常痛苦，看的人也相当难受（可读性低）。

所以我们需要一个可以直接修改UIView.frame中某一个值的方法，这个方法我们可以给view添加一个category 来实现。

首先我们需要创建一个UIView的category，命名随意，需要在.h中暴露我们想要修改的属性：

#import <UIKit/UIKit.h>

@interface UIView (Layout)

@property (assign, nonatomic) CGPoint   origin;
@property (assign, nonatomic) CGFloat   x;
@property (assign, nonatomic) CGFloat   y;

@property (assign, nonatomic) CGFloat   centerX;
@property (assign, nonatomic) CGFloat   centerY;

@property (assign, nonatomic) CGSize    size;
@property (assign, nonatomic) CGFloat   width;
@property (assign, nonatomic) CGFloat   height;

@property (assign, nonatomic) CGFloat   top;
@property (assign, nonatomic) CGFloat   bottom;
@property (assign, nonatomic) CGFloat   left;
@property (assign, nonatomic) CGFloat   right;

@end

然后在.m文件中手动实现各个属性的setter和getter方法：

#import "UIView+Layout.h"

@implementation UIView (Layout)

/*
 @dynamic告诉编译器属性的setter和getter方法都自己实现
 */
@dynamic top;
@dynamic bottom;
@dynamic left;
@dynamic right;

@dynamic origin;
@dynamic x;
@dynamic y;


@dynamic size;
@dynamic width;
@dynamic height;

#pragma mark - top

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

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

#pragma mark - bottom

- (CGFloat)bottom
{
    return self.frame.size.height + self.frame.origin.y;
}

- (void)setBottom:(CGFloat)bottom
{
    CGRect frame = self.frame;
    frame.origin.y = bottom - frame.size.height;
    self.frame = frame;
}

#pragma mark - left

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

- (void)setLeft:(CGFloat)left
{
    CGRect frame = self.frame;
    frame.origin.x = left;
    self.frame = frame;
}

#pragma mark - right

- (CGFloat)right
{
    return self.frame.size.width + self.frame.origin.x;
}

- (void)setRight:(CGFloat)right
{
    CGRect frame = self.frame;
    frame.origin.x = right - frame.size.width;
    self.frame = frame;
}

#pragma mark - origin

- (CGPoint)origin
{
    return self.frame.origin;
}

- (void)setOrigin:(CGPoint)origin
{
    CGRect frame = self.frame;
    frame.origin = origin;
    self.frame = frame;
}

#pragma mark - x

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

- (void)setX:(CGFloat)value
{
    CGRect frame = self.frame;
    frame.origin.x = value;
    self.frame = frame;
}

#pragma mark - y

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

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

#pragma mark - centerX

- (CGFloat)centerX
{
    return self.center.x;
}

- (void)setCenterX:(CGFloat)centerX
{
    CGPoint center = self.center;
    center.x = centerX;
    self.center = center;
}

#pragma mark - centerY

- (CGFloat)centerY
{
    return self.center.y;
}

- (void)setCenterY:(CGFloat)centerY
{
    CGPoint center = self.center;
    center.y = centerY;
    self.center = center;
}

#pragma mark - size

- (CGSize)size
{
    return self.frame.size;
}

- (void)setSize:(CGSize)size
{
    CGRect frame = self.frame;
    frame.size = size;
    self.frame = frame;
}

#pragma mark - width

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

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

#pragma mark - height

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

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

@end

现在只需要这样就能修改UIView.frame中的任意值：

view.x = 100;

既简洁又方便。