stretch a Image like android nine-patch?

Question

UIImage Method :

- (UIImage *)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight.

Here the stretchable area is forced to be a single pixel high/wide.

I can not set the stretchable area, so I want to know: is there a UIImage category to do that?

After I googled, I found a lib.

Question: Is there a nine-patch loader for iPhone?

Announcement: http://blog.tortuga22.com/2010/05/31/announcing-tortuga-22-ninepatch/

This is a source pic, and I want to stretch the inside gray rect.

Thanks in advance.

there may have a better solution,like a uiimage category,sth like this: - (UIImage *)imageWithStretchableRect:(CGRect)rect destRect:(CGRect)destRect — guoxj, Oct 26 '11 at 05:08
i use this lib,and the affect is not what i want . i want to repeat some part of the image . — guoxj, Oct 26 '11 at 08:17

score 20 · Answer 1 · edited Mar 13 '17 at 12:59

20

One way to achieve this is using the below approach,

UIImage * backgroundImg = [UIImage imageNamed:@"bg.png"];

backgroundImg = [backgroundImg resizableImageWithCapInsets:UIEdgeInsetsMake(2,2, 2, 2)];

[imgView setImage: backgroundImg];

UIEdgeInsetsMake(2,2, 2, 2) is the amount of pixels you want unstretchable.

edited Mar 13 '17 at 12:59

Spidy

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answered Oct 11 '12 at 14:53

aToz

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score 4 · Answer 2 · answered Dec 26 '12 at 14:35

You can achieve nine patch with Tortuga22 software

You can find source from this GitHub here

Use it like this

[btnSubmit setImage: [TUNinePatchCache imageOfSize:[btnSubmit bounds].size 
                                forNinePatchNamed:@"imgNormalBackground"]
                       forControlState:UIControlStateNormal];

score 2 · Answer 3 · answered Nov 28 '11 at 07:02

2

As of iOS5, you can use resizableImageWithCapInsets: to achieve this.

answered Nov 28 '11 at 07:02

jrturton

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score 1 · Answer 4 · answered Sep 09 '13 at 23:17

I didn't want to load so much code for the simple 9 patch images we had. So anyway, here's a simple solution to the problem for those interested. It's somewhat hard coded to our 3 pixel stretch regions but you could easily adjust those to your needs or find those in the image with some basic code and use that instead of my hard-coded inset parameters.

+ (UIImage *) makeNinePatchImage:(UIImage *)image;
{
    //Clear the black 9patch regions
    CGRect imageRect = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
    UIGraphicsBeginImageContextWithOptions(image.size, NO, [UIScreen mainScreen].scale);
    [image drawInRect:imageRect];

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextClearRect(context, CGRectMake(0, 0, image.size.width, 1));
    CGContextClearRect(context, CGRectMake(0, 0, 1, image.size.height));

    image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UIEdgeInsets insets;

    //hard coded for now, could easily read the black regions if necessary
    insets.left = insets.right = image.size.width / 2 - 1;
    insets.top = insets.bottom = image.size.height / 2 - 1;

    UIImage *nineImage = [image resizableImageWithCapInsets:insets     
                          resizingMode:UIImageResizingModeStretch];

    return nineImage;

}

Then to use it in say, a button's background, just call it like this:

[self.dummyButton setBackgroundImage:[EVUtility makeNinePatchImage:learnMoreImage] forState:UIControlStateNormal];

Done.

score 0 · Answer 5 · answered Oct 27 '11 at 15:00

0

If I understand it right, you want the rectangle to grow in length and height. While there may be a more efficient solutions, what I could suggest is to break the boundary into a basic unit. Add this image repeatedly one next to the other to form the border rectangle of desired length and height. Then paint the inner rect with gray color.

answered Oct 27 '11 at 15:00

Manali

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yes,exactly.i just want to repeat only part of image http://stackoverflow.com/questions/7901059/how-to-repeat-only-part-of-an-image thanks for you reply. your answer did help me – guoxj Oct 29 '11 at 02:08

stretch a Image like android nine-patch?

5 Answers5