【移動應(yīng)用開發(fā)技術(shù)】iOS中圖片拉伸有哪些方法

【移動應(yīng)用開發(fā)技術(shù)】iOS中圖片拉伸有哪些方法

1.UIImageView整體拉伸typedef

NS_ENUM(NSInteger,

UIViewContentMode)

{

UIViewContentModeScaleToFill,

//

默認(rèn)

拉伸（會變形）

UIViewContentModeScaleAspectFit,

//

等比例拉伸

UIViewContentModeScaleAspectFill,

//

等比例填充

UIViewContentModeRedraw,

//

redraw

on

bounds

change

(這個不清楚)

UIViewContentModeCenter,

//

下面的就是不拉伸按位置顯示了

UIViewContentModeTop,

UIViewContentModeBottom,

UIViewContentModeLeft,

UIViewContentModeRight,

UIViewContentModeTopLeft,

UIViewContentModeTopRight,

UIViewContentModeBottomLeft,

UIViewContentModeBottomRight,

};2.UIImage局部拉伸//

按4邊間距顯示不拉伸的區(qū)域

-

(UIImage

*)resizableImageWithCapInsets:(UIEdgeInsets)capInsets

NS_AVAILABLE_IOS(5_0);

//

按2點拉伸

-

(UIImage

*)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth

topCapHeight:(NSInteger)topCapHeight;

-

(UIImage

*)resizableImageWithCapInsets:(UIEdgeInsets)capInsets

resizingMode:(UIImageResizingMode)resizingMode;

//

拉伸模式

typedef

NS_ENUM(NSInteger,

UIImageResizingMode)

{

UIImageResizingModeTile,//進行區(qū)域復(fù)制模式拉伸

UIImageResizingModeStretch,//進行漸變復(fù)制模式拉伸

};3.UIImage修改大小//內(nèi)縮放，一條變等于最長邊，另外一條小于等于最長邊

-

(UIImage

*)scaleToSize:(CGSize)newSize

{

CGFloat

width

=

self.size.width;

CGFloat

height=

self.size.height;

CGFloat

newSizeWidth

=

newSize.width;

CGFloat

newSizeHeight=

newSize.height;

if

(width

<=

newSizeWidth

&&

height

<=

newSizeHeight)

{

return

self;

}

if

(width

==

0

||

height

==

0

||

newSizeHeight

==

0

||

newSizeWidth

==

0)

{

return

nil;

}

CGSize

size;

if

(width

/

height

>

newSizeWidth

/

newSizeHeight)

{

size

=

CGSizeMake(newSizeWidth,

newSizeWidth

*

height

/

width);

}

else

{

size

=

CGSizeMake(newSizeHeight

*

width

/

height,

newSizeHeight);

}

return

[self

drawImageWithSize:size];

}

-

(UIImage

*)drawImageWithSize:

(CGSize)size

{

CGSize

drawSize

=

CGSizeMake(floor(size.width),

floor(size.height));

UIGraphicsBeginImageContext(drawSize);

[self

drawInRect:CGRectMake(0,

0,

drawSize.width,

drawSize.height)];

UIImage

*newImage

=

UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return

newImage;

}4.images.xcassets/upload/information/20200623/126/122621.jpg/upload/information/20200623/126/122622.jpg/upload/informa