I've got an image view that I want to show a central slice of the user's profile picture. I want to scale the picture so that the width matches the width of the screen while maintaining the aspect ratio, center the image, and then have any extra on the top/bottom to not appear at all.
I've tried setting the imageView.contentMode to UIViewContentModeScaleAspectFill, UIViewContentModeScaleAspectFit, UIViewContentModeCenter and a few others, but it either resizes my UIImageView, changes the aspect ratio, or doesn't fill the area.
"but it either resizes my UIImageView"
I guess you see the cropped parts.
Maybe you forgot the "clipsToBounds" property?
UIImageView *view1 = [[UIImageView alloc] initWithFrame: ___ ];
view1.clipsToBounds = YES;
UIImage * img = [UIImage imageNamed:#" ___ "];
view1.image = img;
view1.contentMode = UIViewContentModeScaleAspectFill;
Related
I have an UIImageView that shows and image of a creditCard, My problem is that I want to make boarders around it, so the credit card wont touch the edges of the UIimageView, I dont want to change the UIImageView position on the screen so what can I do ?
image 1
image 2
( unlike the example of the blue card it dosnt have to leave spaces only from the sides, it could shrink it from all sides )
You basically have (3) three options that can fix this.
Adjust the UIViewContentMode contentMode of the UIImageView so that it appropriately displays the image (this will only work however if the image you are using scales to fit without touching the border.
Use a UIButton instead and simply adjust the image insets until your satisfied (just disable the button or set user interaction to no here to "mimic" an image view)
Create a wrapper method that creates a new image to your desired size. Something like this should work just fine
CGSize size = CGSizeMake(< some width > , < some height >);
Then just create a new image capture with the size you've chosen
CGFloat scale = MAX(size.width/image.size.width, size.height/image.size.height);
CGFloat width = image.size.width * scale;
CGFloat height = image.size.height * scale;
CGRect imageRect = CGRectMake((size.width - width)/2.0f,
(size.height - height)/2.0f,
width,
height);
UIGraphicsBeginImageContextWithOptions(size, NO, 0);
[image drawInRect:imageRect];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
From here you should then be able to just apply a border width and color to get your desired result!
I guess a fourth (4th) option could be manually shrinking the image (with some photo editor) so that it renders (fits) into your image view with the appropriate padding around the image. I think the others are easier and best practice though.
When you set a image for a uiimageview in storyboard or interface builder, it retains the shape of the original UIImageView, which means that the image itself is completely distorted.
To match the size of the UIImageView to its image, I have to manually enter in the size from the file inspector.
Is there a way that UIImageView can automatically detect the native size of its image and size its self accordingly?
I am assuming you are referring to layout in storyboard/IB. To get the native size of the image just select the image and press Command + = on the keyboard. the to re-size it proportionally select the corner and hold down the shift key when you re-size it.
Why don't you set the size of your uiimageview in code?
Here's what you need to do...
//get the Image
UIImage *img = [UIImage imageNamed:#"img.png"];
CGFloat x = img.origin.x;
CGFloat y = img.origin.y;
CGFloat width = img.size.width;
CGFloat height = img.size.height;
imageView.frame = CGRectMake(x, y, width, height); //imageView is your uiimageview's reference
Use the contentMode
imageView.contentMode = UIViewContentModeScaleAspectFit;
Edit :
I just saw you seem to want to adjust imageViews size to the image.... Different then
This is what I did:
imageView.clipsToBounds = YES;
[imageView setContentMode: UIViewContentModeScaleAspectFit];
That is working for me.
I have some images I need to get from the web. Just using data from a URL.
They need to show correctly on Retina Display.
When I get the images from the web, they still look pixelated. I need to set the images' scale to retina display (2.0), but I must be missing something.
Here's what I did so far.
UIImage *img = [UIImage imageWithData:[NSData dataWithContentsOfURL:#"http://www.msdomains.com/tmp/test.png"];
CGRect labelFrame = CGRectMake(0,0,64,64);
UIImageView *imageView = [[UIImageView alloc] initWithFrame:labelFrame];
imageView.contentScaleFactor = [UIScreen mainScreen].scale;
[imageView setImage:img];
[self addSubview:imageView];
[imageView release];
Try adding ##2x.png at the end of your URL. That wont change the URL, but the image will be recognized as a retina #2x image. It worked for me, but I used this method with SDWebImage.
e.g. using http://www.msdomains.com/tmp/test.png##2x.png.
Your code should work pretty much as-is. I don't know what the original dimensions of your image were, but I'd guess they were 64x64 px. In order to scale down correctly, the original image would need to be 128x128 px.
As a test, the following code correctly displayed my photo in Retina resolution on the Simulator, and on my iPhone 4:
UIImage *img = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"http://www.seenobjects.org/images/mediumlarge/2006-08-19-native-lilac.jpg"]]];
CGRect labelFrame = CGRectMake(0, 0, 375, 249.5);
UIImageView *imageView = [[UIImageView alloc] initWithFrame:labelFrame];
[imageView setImage:img];
[self.view addSubview:imageView];
Note that the UIImageView is 375x249.5 points, which is half of the original (pixel) dimensions of the photo. Also, setting the contentScaleFactor didn't seem to be necessary.
(As an aside, I can't see that specifying #2x on the URL will help, in this case, as the call to dataWithContentsOfURL: will return an opaque blob of data, with no trace of the filename left. It's that opaque data that's then passed to imageWithData: to load the image.)
when you directly assign the image URL to imageView, it will not take it as retina.
imageView.imageURL = [NSURL URLWithString:#"http://example.com/image.png"];
will not give you a retina image.
So, inspite your image is 200x200 but if your imageView is 100x100 then it will take 100x100 from the downloaded image and show pixelated image on retina devices.
Solution would be to use the image property of imageView instead of imageURL.
imageView.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"http://example.com/image.png"]]];
This will assign 200x200 image to the imageView of 100x100 and hence the image will not be pixelated.
For retina display, add the same image with the resolution which is exactly the double of the original image. dont forget to add "#2x"at the end of this image name... e.g. "image_header.png" is an image 320x100 then another image with name "image_header#2x.png" (dimension 640x200) will be selected for the retina display automatically by the OS...
hope it helps
I am trying to adjust the height of an image by stretching it.
This is what I've got so far:
-(IBAction)buttonTapped{
UIImage *img = [UIImage imageNamed:#"water.png"];
[water1 setImage:img];
}
-(IBAction)button2Tapped
+ (UIImage*)imageWithImage:(UIImage*)img
scaledToSize:(CGSize)newSize;
{
UIGraphicsBeginImageContext( newSize );
[img drawInRect:CGRectMake(0,2,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;}
and this is in my view controller.h
IBOutlet UIImageView *water1;
-(IBAction)buttonTapped;
-(IBAction)button2Tapped;
I am not sure what I need to change to make this correct, or if I should start again with a new way.
I want it so that when I push a button, an image appears, then it resizes it when I push another button.
Thanks for helping!
You can simply change the size of the UIImageView property, in order to get the size you want.
Set the contentMode of the UIImageView to wathever fits your need, and it will automatically resize to the given size (either scaling to fit or stretching).
I was hoping there was some sort of function that could take the real size of my picture
CGRect myImageRect = CGRectMake(0.0f, 0.0f, 320.0, 210.0f); // 234
UIImageView *myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:#"start.png"]];
And with CGRectMake which does something like this ..( imageViewHeight ,
CGFloat imageViewHeight = [myImage frame].size.height;
So that I could get the real size instead of having to define it like you can seen above.
I don't really get what you're asking, but here's a shot:
If you have a UIImage, and you want to know its size, you can ask it for its -[UIImage size] property.
However, if you want to create a UIImageView that's the same size as a UIImage, then you can just use -[UIImageView initWithImage:], which will automatically set the frame of the UIImageView to correspond to the dimensions of the image.
If, however, you're just looking to change the dimensions of a currently existing view, there's really no easy way to do that without messing around with the view's frame. You could maybe apply an affine transform to scale it, but it's easier to manipulate the frame.
It looks like you're asking to add the image to the imageview without first creating a frame. If this is the case, you can do the following:
UIImageView *myImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"start.png"]];
As far as I understood, you are looking for the size of the image used in UIImageView object. To do that, there is not a function built in UIImageView but you can do it this way:
NSString* image= [myImage image].accessibilityIdentifier; // Get the image's name
UIImage *img = [UIImage imageNamed:image]; // Create an image object with that name
CGSize size = img.size; // Get the size of image
Hope this helps your question.