iOS UIView 快速修改 frame

我们修改frame中的某个值，需要进行繁琐的书写，例如：

(1). 直接设置位置大小

view.frame = CGRectMake(0, 0, 320, 150);

(2). 只修改某个值

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

这种写法在界面元素较多的排版中，会让程序员非常痛苦，而且可读性也会减弱

如果能够人性化一点，可以单独地修改某个值，或者再人性化一点，可以输出view中每一个点的坐标，将更有利于布局。我们可以通过建立view的类别 category 来实现这个人性化的布局操作

一、建立类别

建立一个名为Layout的UIView类别，类别的代码如下：

1. UIView+Layout.h

.h 文件定义了 x, y, width, height 等方便读写的属性，代码如下：

#import <UIKit/UIKit.h>

@interface UIView (Layout)

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

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

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

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

@end

2. UIView+Layout.m

.m 文件实现各个属性的setter和getter方法，代码如下：

#import "UIView+Layout.h"

@implementation UIView (Layout)

@dynamic top;
@dynamic bottom;
@dynamic left;
@dynamic right;

@dynamic width;
@dynamic height;

@dynamic size;

@dynamic x;
@dynamic y;

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

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

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

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

- (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;
}

- (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;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

@end

二、使用

类别创建完成以后，view的布局就显得轻松很多了 例如原来你要修改y坐标时要这样写：

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

而现在只需要这样写：

view.y = 100;

既简洁又方便