I have the following code:
UIImageView * imgView = [[UIImageView alloc] initWithImage:image];
NSLog(#"IMAGE SIZE WIDTH IS %f AND HEIGHT IS %f", imgView.frame.size.width, imgView.frame.size.height);
[imgView setUserInteractionEnabled:YES];
[imgView setContentMode:UIViewContentModeScaleAspectFit];
CGRect frame = imgView.frame;
frame.size.width = SCREEN_WIDTH_PORTRAIT;
[imgView setFrame: frame];
however, the height of this view did not change accordingly, what is wrong?
You're telling the view's content to scale, not the view itself. You will have to set both the width and the height to do that.
If you're just trying to scale with orientation changes, though, you could use the UIViewAutoresizingMask and set it like this:
imgView.autoresizingMask = UIViewAutoresizingFlexibleWidth| UIViewAutoresizingFlexibleHeight;
That will make it stretch when switching orientations automatically.
Edit:
Here's how you would change the height and maintain the ratio, and animate to the new frame:
CGRect frame = imgView.frame;
float ratio = frame.size.width/SCREEN_WIDTH_PORTRAIT;
frame.size.width = SCREEN_WIDTH_PORTRAIT;
frame.size.height *= ratio;
[UIView animateWithDuration:.25 animations:^{
[imgView setFrame: frame];
}];
The image will fit to the frame with the same height as you are only changing the width. So, depending on the aspect ratio of the image, the image may not change it's size. You could determine the aspect ratio of the UIImage and then calculate the height from that with the new width.
Related
I am facing one strange issue when adding UILabel to zoomed UIScrollview problem.
I am adding two views to zoomed UIScrollview
1. UIImageView
2. UILabelView
Here the code am using to add UIImageView on UIScrollview
float recentZoomScaleValue = 4.5;
CGRect rect = CGRectMake(x, y, 150, 150);
UIImageView *signatureImage = [[UIImageView alloc]initWithFrame:rect];
[signatureImage setImage:image];
[signatureImage setFrame:rect];
//resize the frame to avoid the auto zoom
CGRect frame = signatureImage.frame;
frame.size.width /= recentZoomScaleValue;
frame.size.height /= recentZoomScaleValue;
[signatureImage setFrame:frame];
[self addSubView:signatureImage];
[self.scrollview addSubView:signatureImage];
Here the code am using to add UILabel on UIScrollview
float recentZoomScaleValue = 4.5;
txtLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 600, self.fontSize)];
[txtLabel setText:#"loganathan is a good boy"];
[txtLabel setFont:[UIFont fontWithName:txtLabel.font.fontName size:self.fontSize]];
[txtLabel setTextColor:[UIColor redColor]];
[txtLabel setBackgroundColor:[UIColor clearColor]];
[txtLabel setAutoresizingMask:UIViewAutoresizingFlexibleHeight];
CGRect frame = signatureImage.frame;
frame.size.width /= recentZoomScaleValue;
frame.size.height /= recentZoomScaleValue;
[txtLabel setFrame:frame];
[self addSubview:txtLabel];
But the problem is when ever i tried to add UILabel view it added with auto zoomed. Since the label text was blurred. I do not know why and what is the problem. Shall i use CATextLayer instead of UILabel?. Any help that might be appreciated.
Thanks
you have to set the contentsScale to the right value when ever the zoomScale changes. Or initial to the current zoomScale:
Example for dynamic zooming:
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale {
[yourLabel.layer setContentsScale:scale*[[UIScreen mainScreen] scale]];
[yourLabel.layer setNeedsDisplay];
}
I have a UIImageView whose frame, set before the image is loaded, is always too large for the image, so when I try to round the corners, for example, nothing happens.
How can I resize the frame so it's the same size as the underlying image, while ensuring that the center point of the UIImageView does not change?
If you change the bounds of a UIView the center will not change.
CGRect bounds;
bounds.origin = CGPointZero;
bounds.size = newImage.size;
imageView.bounds = bounds;
imageView.image = newImage;
try something along the following lines.. not tested
CGSize imageSize = image.Size;
CGPoint oldCenter = imageView.center;
// now do some calculations to calculate the new frame size
CGRect rect = CGRectMake(0, 0, imageSize.width, imageSize.height);
imageView.frame = rect;
imageView.center = oldCenter;
i have picture like this image it will present on Landscape Mode
so if rotate device to Portrait, how to present image like this
Use an UIImageView with these settings:
imageView.autoresizingMask = (UIViewAutoresizingFlexibleWidth |
UIViewAutoresizingFlexibleHeight);
imageView.contentMode = UIViewContentModeScaleAspectFit;
It looks like what you're trying to do is clip the image on the right, while leaving the top, left, and bottom the same.
Two things to try:
1) Subclass UIView and in the drawRect method, adjust the rect and draw out the clipped image using CGContextDrawImage (context, rect, sourceImage.CGImage).
2) Use CALayers. You can adjust the 'contentsRect' of the imageView's layer:
CALayer* imageLayer = imageView.layer;
imageLayer.masksToBounds = YES;
CGRect rect;
if (inPortrait)
rect = CGRectMake(0.0, 0.0, 0.5, 1.0); // half size
else
rect = CGRectMake(0.0, 0.0, 1.0, 1.0); // full size
imageLayer.contentsRect = rect;
This slices the image in half along width. masksToBounds takes care of clipping sublayers (in case you have them). You can tweak the contentsRect unit rectangle to adjust where you want the cutoff. You may also want to adjust the imageView's own bounds as well to match the size.
This has an added bonus in that adjusting the contentsRect is automatically animated so when you do the rotation the width animates in and out nicely.
// Set the layer contents
view.layer.contents = [image CGImage];
// Stretch so that contents overflows the edges and keeps aspect ratio
view.layer.contentsGravity = kCAGravityResizeAspectFill;
// Clip off the overflow
view.layer.masksToBounds = YES;
// Set the frame
CGRect frame;
frame.origin = CGPointZero;
frame.size = view.superview.bounds.size;
view.frame = frame;
// Make sure it resizes when the superview does
view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
You will have to work with view's layer.
You can find the appropriate guidelines at https://developer.apple.com/iphone/library/documentation/Cocoa/Conceptual/CoreAnimation_guide/Articles/Layers.html
Hope this helps.
Thanks,
Jim.
How would you change just the width of a UIImageView in objective-c? Currently I'm doing this:
imageview.frame = GCRectMake(x,y,width,height);
But when I change the width it seems to just change the position rather then change the size.
try this:
CGRect frame = [imageView frame];
frame.size.width = newWidth;
[imageView setFrame:frame];
I've read various posts on here asking similar questions... I've tried various ways that were posted including bounds and frames etc. including the following:
myImage.frame = CGRectMake(0.0f, 0.0f,50.0f, 50.0f);
and:
myImage.bounds = CGRectMake(0.0f, 0.0f,50.0f, 120.0f);
neither of those work.
However, I find it interesting that the following code let's me move the Image around but doesn't change the width:
CGRect frameRect = myImage.frame;
frameRect.size.width = 50.0f;
frameRect.origin.x += 10.5f;
myImage.frame = frameRect;
So why don't any of these change the width/height of my ImageView?
I found another post on here that basically states I have to right a small book of code to get it resize my image... is that true?
Such as this one:
UIImage: Resize, then Crop
certainly this is simpler than that??
The following will change the size of the UIImaveView, clipping the underlying image without resizing it and keeping it aligned to bottom left of view:
imageView.frame = CGRectMake(
imageView.frame.origin.x,
imageView.frame.origin.y, newWidth, newHeight);
imageView.contentMode = UIViewContentModeBottomLeft; // This determines position of image
imageView.clipsToBounds = YES;
First off, you can't set the frame or bounds of the UIImage - that will only work on a UIImageView.
I've found that changing the frame of a UIImageView causes the Image to be scaled to the new size. Sometimes, that's undesirable - and you want instead to crop the image.
I can't tell if this is what you're asking for, but here's some code to crop an image to a specific size in a UIImageView:
UIImage *myImage = [UIImage imageNamed:#"photo.png"];
CGRect cropRect = CGRectMake(0.0, 0.0, 320.0, 44.0));
CGImageRef croppedImage = CGImageCreateWithImageInRect([myImage CGImage], cropRect);
UIImageView *myImageView = [[UIImageView alloc] initWithFrame:cropRect];
[myImageView setImage:[UIImage imageWithCGImage:croppedImage]];
CGImageRelease(croppedImage);
From what I get of the question, the OP wanted to change the size of the UIImageView when the size of the container UIView is changed. The code below will do it...
UIView * foo = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 25, 25)] autorelease];
foo.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
UIImageView * bar = [[UIImageView alloc] initWithImage:
[UIImage imageNamed:#"test.png"]];
bar.autoresizingMask = foo.autoresizingMask;
[foo addSubview:bar];
[self.view addSubview:foo];
The key here are the foo.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight and the bar.autoresizingMask = foo.autoresizingMask; lines. Forget either of these, and the whole jigmarole will stop working.
Well, if your read the documentation about UIIMage you can notice that is impossible to change any parameter of an UIImage after create it, the solution I've implemented for use high quality images for change some parameter of (for example) the SliderControl as Screw Image, is the next one:
UIImage *tumbImage= [UIImage imageNamed:#"screw.png"];
UIImage *screw = [UIImage imageWithData:UIImagePNGRepresentation(tumbImage) scale:2];
With that, I can to use 100x100 px image in my apps scaled to 50%.
Kind regards.
Try Using a UIScrollView. Add the UIImageView to the UIScrollView in Interface Builder you can then control the position and size of the image as follows:
CGRect rect = [scrollView frame];
rect.origin.x = 50.0f;
rect.origin.y = 0.0f;
rect.size.width = 320.0f;
rect.size.height = 150.0f;
[scrollView setFrame:rect];
If you tried those methods cannot work, the only way to do it is to add the constraint of width and height to the UIImageView.
// Create the constraint in code
NSLayoutConstraint *constraint0 = [NSLayoutConstraint constraintWithItem: myImage attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeWidth multiplier:1.0f constant: yourNewsWidth];
NSLayoutConstraint *constraint1 = [NSLayoutConstraint constraintWithItem: myImage attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant: yourNewsHeight];
[myImage addConstraint:constraint0];
[myImage addConstraint:constraint1];
Use myImageView.frame = myNewPosAndSize; to resize or reposition your image view (as with any other view). It might confuse you that the image view draws its image with its original size, possibly exceeding its own dimensions. To disable this use myImageView.clipsToBounds = NO;
You don't have to write a whole book, you can copy that code.
I believe the UIImageView always draws the image at 0,0 at a 1.0 scale. You'll need to resize the image if you want to continue using the UIImageView.