UIButton top border appears thicker than the following ,but sometimes correct ，why?
code:
UIImage * sanImage = [UIimage imageNamed:#"product_bt1_normal"];
[self.saveBtn setBackgroundImage:[sanImage
stretchableImageWithLeftCapWidth:sanImage.size.width/3
topCapHeight:sanImage.size.height/3] forState:UIControlStateNormal];
Are you trying to make a button? If so, perhaps use a UIButton instead? You can control the border with button.layer.borderWidth = 1.0f
If you're set on using an image, create a UIImageView, and modify the border thickness that way:
UIImageView *iv = [[UIImageView alloc] initWithImage:sanImage];
[iv.layer setBorderWidth:0.5f];
It could be because of off-pixel boundaries. Since you are using height/3.0f, your image is maybe not returning a well-behaved image.
Also, there is a new stretchable image method you should be using, resizableImageWithCapInsets:.
So try this code out:
[self.saveBtn setBackgroundImage:[sanImage resizableImageWithCapInsets:UIEdgeInsetsMake(3.0f, 3.0f, 3.0f, 3.0f)] forState:UIControlStateNormal];
You might need to mess with the values for the insets a bit, I don't know the dimensions of your button image.
This is the first time I have ever designed an iOS app so I want to make sure I understand this behavior correctly.
I designed a custom bar button icon for a navigation bar in Photoshop. The final image that I saved in Photoshop was 102 x 45, and yes I realize that these dimensions are bigger than the recommended 44x44 in the iOS 7 design guidelines.
Anyways, I placed my image into the asset folder, and then programmatically set the bar button item with the following code:
UIImage* firstButtonImage = [UIImage imageNamed:#"loginbutton1"];
CGRect frame = CGRectMake(0, 0, 102, 45);
UIButton * someButton = [[UIButton alloc] initWithFrame:frame];
[someButton setBackgroundImage:firstButtonImage forState:UIControlStateNormal];
[someButton addTarget:self action:#selector(didTapLoginButton:)
forControlEvents:UIControlEventTouchUpInside];
self.rightBarButton = [[UIBarButtonItem alloc] initWithCustomView:someButton];
self.navItem.rightBarButtonItem = self.rightBarButton;
As you can see I set the frame's width and height to the exact size of the image. When I first ran the app, I didn't like the image and thought it was too big. So I changed the width and height parameters in this statement:
CGRect frame = CGRectMake(0, 0, 70, 30);
And now the image looks perfect on the iPhone screen. This is on an iPhone 4s.
So my main question is, what is actually happening when I change the frame size? Since the frame is now smaller than the actual image size, does the image just get scaled down automatically to fit inside the frame?
Yes the image get scaled because you are using backgroundImage (not Image). Both images have different behaviors.
Check the Xcode Interface Builder, you can see there, that you can set two images: Image and Background. Background is the UIImage that get scaled for the whole frame of the UIButton.
The UIButton Class Reference allows you to access the imageView of the image (not theimageView of the backgroundImage)
Because you have access to the imageView, you can change the mode of the image with:
[[someButton imageView] setContentMode:UIViewContentModeBottomLeft];
In UIView Class Reference you can check all the UIViewContentModes provided by Apple.
You can check that changing a little bit your code:
[someButton setImage:firstButtonImage forState:UIControlStateNormal];
[[someButton imageView] setContentMode:UIViewContentModeBottomRight];
It turns out that UISlider has a lower limit for its frame height. On iOS 6 it's 23px and on iOS 7it's 34 px. But that's too much for me and i need to make it smaller. How can i do that without using CGAffineTransformMakeScale (i tried that already and don't like how it looks)? Or maybe i'm just missing something really simple?
There's no properties you could use to do that.
I did find a github project which allows you set the the height of the bar.
Or have a look at the results on Cocoa Controls for 'Slider'.
Assign height constraint to slider in storyboard.
You have to use images of smaller size :
[slider setThumbImage:[UIImage imageNamed:#"Thumb"] forState:UIControlStateNormal]; // slider thumb should be square image
[slider setThumbImage:[UIImage imageNamed:#"Thumb"] forState:UIControlStateHighlighted]; // slider thumb on touch
[slider setMinimumTrackImage:[UIImage imageNamed:#"rMin"] forState:UIControlStateNormal]; // thumb left part
[slider setMaximumTrackImage:[UIImage imageNamed:#"Max"] forState:UIControlStateNormal]; // thumb right part
choose images carefully, now its photoshop work
I'm trying to create a UISlider with a custom thumb image. This works fine, but does not work if I disable the slider. Here's my code:
UISlider *slider = [[UISlider alloc]initWithFrame:CGRectMake(130, 10, sliderBG.size.width, sliderBG.size.height)];
slider.enabled = NO;
[slider setThumbImage:thumbCircle forState:UIControlStateHighlighted];
2 questions:
1) It's using the right image when I set state for UIControlStateHighlighted, but not when I set state to UIControlStateDisabled. Why?
2) The thumb image looks transparent. My image is not transparent. Is the UISlider doing this? Any way to get around it?
Thanks!
That is how UISlider work: use a transparent knob to indicate inactivity. If you want one that does not do that, try recreate it yourself using several UIImageView's and following a finger isn't that difficult on iOS.
Try adding:
[slider setThumbImage:thumbCircle forState: UIControlStateDisabled ];
firstButton is a UIButton of type Custom. I'm programmatically putting three of them across each cell of a table, thusly:
[firstButton setImage:markImage forState:UIControlStateNormal];
[firstButton setContentMode:UIViewContentModeScaleAspectFit];
[cell.contentView addSubview:firstButton];
Elsewhere, I'm telling it to clipToBounds. What I get is a crop of the center square of the image, rather than an aspect-scaled rendering of it. I've tried this lots of ways, including setting the mode property on firstButton.imageView, which also doesn't seem to work.
I had the same problem. I see this question is a little old, but I want to provide a clear and correct answer to save other folks (like me) some time when it pops up in their search results.
It took me a bit of searching and experimenting, but I found the solution. Simply set the ContentMode of the "hidden" ImageView that is inside the UIButton.
[[firstButton imageView] setContentMode: UIViewContentModeScaleAspectFit];
[firstButton setImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];
Perhaps that's what Dan Ray was alluding to in his accepted answer, but I suspect not.
If you're dealing with the UIButton's image (as opposed to it's backgroundImage), setting the contentMode on the UIButton itself or on its imageView has no effect (despite what other answers say).
Alternatively do this instead:
self.button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentFill;
self.button.contentVerticalAlignment = UIControlContentVerticalAlignmentFill;
Or size your image accordingly.
OR just use a UIImageView (which properly respects contentMode) with a UITapGestureRecognizer attached to it, or a transparent UIButton on top of it.
Rather than setting the contentMode on the button itself, you'll want to set contentHorizontalAlignment and contentVerticalAlignment properties and (crucially) the contentMode for the button's imageView for any kind of aspect fill or fit:
button.contentHorizontalAlignment = .fill
button.contentVerticalAlignment = .fill
button.imageView?.contentMode = .scaleAspectFit
You can also do other things like aligning the button's image to the top. If you don't need an aspect fill or fit, you just can set the alignment by itself:
button.contentVerticalAlignment = .top
After a couple of hours of confusion, here's how I got it to work under iOS 3.2. As dusker mentioned, using setBackgroundImage instead of setImage did the job for me.
CGRect myButtonFrame = CGRectMake(0, 0, 250, 250);
UIImage *myButtonImage = [UIImage imageNamed:#"buttonImage"];
UIButton *myButton = [UIButton buttonWithType:UIButtonTypeCustom];
[myButton setBackgroundImage:myButtonImage forState:UIControlStateNormal];
[myButton setFrame: myButtonFrame];
[myButton setContentMode: UIViewContentModeScaleAspectFit];
The answer is to use a UIImageView with all the lovely Content Mode settings you want, and then layer a custom button on top of it. Dumb that you can't do that all in one shot, but it appears that you can't.
These two things (which are quite hard to find initially) will stretch your UIButton image to fit the button size:
one should always try to set such in the Storyboard rather than code.
Found a fix for this. Set the adjustsImageWhenHighlighted property of UIButton to NO.
UIButton *b = [[UIButton alloc] initWithFrame:rect];
[b setImage:image forState:UIControlStateNormal];
[b.imageView setContentMode:UIViewContentModeScaleAspectFill];
[b setAdjustsImageWhenHighlighted:NO];
Hope this helps. Feel free to comment below, I will follow up on any questions that you have.
My answer is similar to Kuba's. I needed my image to be programatically set.
UIImage *image = [[UIImage alloc] initWithContentsOfFile:...];
[button setBackgroundImage:image forState:UIControlStateNormal];
button.imageView.contentMode = UIViewContentModeScaleAspectFill; //this is needed for some reason, won't work without it.
for(UIView *view in button.subviews) {
view.contentMode = UIViewContentModeScaleAspectFill;
}
Only solution which worked for me:
[button setImage:image forState:UIControlStateNormal];
button.imageView.contentMode = UIViewContentModeScaleAspectFill;
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentFill;
button.contentVerticalAlignment = UIControlContentVerticalAlignmentFill;
Swift 3
self.firstButton.imageView?.contentMode = .scaleAspectFill
For anyone experiencing this on iOS 15 and Xcode 13, see Matt's answer in this other question.
The behavior of Xcode changed and now defaults UIButtons from the library to the plain style, which prevents the child image from scaling as expected.
Instead of setImage try setBackgroundImage
I believe we have a simple interface builder issue here - apparently the IB ignores any content-mode changes AFTER you have set the image-property.
the solution is as simple: set the content mode, remove previously set image-names (make sure you remove it in all states, default, highlighted etc.), then re-enter the desired image-names in all desired states - et voilà.
I also advice to have a look at the adjustsImageWhenHighlighted UIButton property to avoid weird deformations of the image, when the button is pressed.
In trying to figure this out, my method got a bit hackier as time went on, and I wound up subclassing UIButton and overriding setHighlighted:
For me it works to just knock down the image alpha to .5, because they're on a black background.
However, it only works if I comment out [super setHighlighted:] (where it appears the image-stretchy code is going on), which just doesn't feel like the right way to solve this at all...everything seems to be working fine, though. We'll see how it holds up as I keep working on it.
- (void)setHighlighted:(BOOL)highlight {
if (highlight) {
[self.imageView setAlpha:.5];
} else {
[self.imageView setAlpha:1];
}
// [super setHighlighted:highlight];
}
If anyone looking for answer that work in iOS 6 and iOS 7 and storyboard:
You can set image in your storyboard:
And then:
for(UIView* testId in self.subviews) {
if([testId isKindOfClass:[UIImageView class]])
[testId setContentMode:UIViewContentModeScaleAspectFill];
}
If the UIButton does not seem to listen to the layout constraint settings, do check whether the images are larger than the button size. Always use the #2x and #3x images for retina resolutions.