【移动应用开发技术】iOS中如何实现图片自适应拉伸效果

【移动应用开发技术】iOS中如何实现图片自适应拉伸效果

前言/upload/information/20200623/126/122012.png//

//

ViewController.m

//

ChatBgTest

//

//

Created

by

李峰峰

on

2017/1/23.

//

Copyright

©

2017年

李峰峰.

All

rights

reserved.

//

#import

"ViewController.h"

@interface

ViewController

()

@end

@implementation

ViewController

-

(void)viewDidLoad

{

[super

viewDidLoad];

[self

addBtn];

}

-(void)addBtn{

//

创建一个按钮

UIButton

*btn

=

[UIButton

buttonWithType:UIButtonTypeCustom];

//

设置按钮的frame

btn.frame

=

CGRectMake(50,

300,

300,

103);

//

加载图片

UIImage

*image

=

[UIImage

imageNamed:@"chat_bg"];

//

设置按钮的背景图片

[btn

setBackgroundImage:image

forState:UIControlStateNormal];

//

将按钮添加到控制器的view

[self.view

addSubview:btn];

}

@end/upload/information/20200623/126/122013.png图片自适应拉伸1、iOS5之前/upload/information/20200623/126/122014.png-

(UIImage

*)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth

topCapHeight:(NSInteger)topCapHeight;/**

第一种拉伸方式（iOS5之前）

*/

-(void)stretchTest1{

//

创建一个按钮

UIButton

*btn

=

[UIButton

buttonWithType:UIButtonTypeCustom];

//

设置按钮的frame

btn.frame

=

CGRectMake(50,

300,

300,

103);

//

加载图片

UIImage

*image

=

[UIImage

imageNamed:@"chat_bg"];

//

设置左边端盖宽度

NSInteger

leftCapWidth

=

image.size.width

*

0.5f;

//

设置上边端盖高度

NSInteger

topCapHeight

=

image.size.height

*

0.5f;

UIImage

*newImage

=

[image

stretchableImageWithLeftCapWidth:leftCapWidth

topCapHeight:topCapHeight];

//

设置按钮的背景图片

[btn

setBackgroundImage:newImage

forState:UIControlStateNormal];

//

将按钮添加到控制器的view

[self.view

addSubview:btn];

}/upload/information/20200623/126/122015.png2、iOS5-

(UIImage

*)resizableImageWithCapInsets:(UIEdgeInsets)capInsetstypedef

struct

UIEdgeInsets

{

CGFloat

top,

left,

bottom,

right;

//

specify

amount

to

inset

(positive)

for

each

of

the

edges.

values

can

be

negative

to

'outset'

}

UIEdgeInsets;/**

第二种拉伸方式（iOS5）

*/

-(void)stretchTest2{

//

创建一个按钮

UIButton

*btn

=

[UIButton

buttonWithType:UIButtonTypeCustom];

//

设置按钮的frame

btn.frame

=

CGRectMake(50,

300,

300,

103);

//

加载图片

UIImage

*image

=

[UIImage

imageNamed:@"chat_bg"];

//

设置端盖的值

CGFloat

top

=

image.size.height

*

0.5;

CGFloat

left

=

image.size.width

*

0.5;

CGFloat

bottom

=

image.size.height

*

0.5;

CGFloat

right

=

image.size.width

*

0.5;

UIEdgeInsets

edgeInsets

=

UIEdgeInsetsMake(top,

left,

bottom,

right);

//

拉伸图片

UIImage

*newImage

=

[image

resizableImageWithCapInsets:edgeInsets];

//

设置按钮的背景图片

[btn

setBackgroundImage:newImage

forState:UIControlStateNormal];

//

将按钮添加到控制器的view

[self.view

addSubview:btn];

}3、iOS6-

(UIImage

*)resizableImageWithCapInsets:(UIEdgeInsets)capInsets

resizingMode:(UIImageResizingMode)resizingModetypedef

NS_ENUM(NSInteger,

UIImageResizingMode)

{

UIImageResizingModeTile,

//

平铺模式，通过重复显示UIEdgeInsets指定的矩形区域来填充图片

UIImageResizingModeStretch,

//

拉伸模式，通过拉伸UIEdgeInsets指定的矩形区域来填充图片

};/**

第三种拉伸方式（iOS6）

*/

-(void)stretchTest3{

//

创建一个按钮

UIButton

*btn

=

[UIButton

buttonWithType:UIButtonTypeCustom];

//

设置按钮的frame

btn.frame

=

CGRectMake(50,

300,

300,

103);

//

加载图片

UIImage

*image

=

[UIImage

imageNamed:@"chat_bg"];

//

设置端盖的值

CGFloat

top

=

image.size.height

*

0.5;

CGFloat

left

=

image.size.width

*

0.5;

CGFloat

bottom

=

image.size.height

*

0.5;

CGFloat

right

=

image.size.width

*

0.5;

//

设置端盖的值

UIEdgeInsets

edgeInsets

=

UIEdgeInsetsMake(top,

left,

bottom,

right);

//

设置拉伸的模式

UIImageResizingMode

mode

=

UIImageResizingModeStretch;

//

拉伸图片

UIImage

*newImage

=

[image

resizableI