I have a UIScrollView whose content is UIImageView, I want to show the image 3 times larger when displayed compared to its original size. I set the zoomscale 3. But it doesn't work.
Make sure you set the zoomScale after you set the content of the UIScrollView.
Related
I am attempting to get the auto-layout to work correctly. For some reason, when I change the size of the device, all of the images and buttons are out of place and don't resize at all. This is true for the 3.5 inch screen, as well as the ipad retina. When I run the simulator, the app shows exactly how it shows in storyboard. Auto-layout should be resizing everything so that this does not happen. please help!
The issue is that constraints don't scale. When you set a constraint height to 200 it will always be 200, even if the screen is only 100 high. So what you need to do is try to set constraints that makes the size dynamically rather then set the constraint height/widths yourself.
For instance, on your first label under the UIImageView set the constraints leading and trailing to 20, then set the label constraint to center horizontally on the UIImageView. No other constraints for the label. This will cause the label to shrink in width since its set to be 20 away from each side. The height will not change since there is nothing "pushing" it to shrink since you are missing a few constraints, but basically you need to use the top, bottom, leading, and trailing, constraints to the UIViewController view in order to "scale" the elements.
If you'd like I could try and set the constraints for you if you upload the project and you can then watch how I did.
Edit
It's hard for me to know what kind of behaviour you'd want, but something has to scale or change size in your set up. The easiest would be to resize the UIImageView. It's basically impossible to make it look exactly alike in every screen size, though, so you'll have to play around a bit with constraints until you understand how they work and how to adjust them according to what you want. One way is to create the layout you want and then connect them to code and scale them depending on size of the screen (this is a bit of a pain, I did that in a project recently and it took a bit of time and effort).
The easiest approach is to make the UIImageView to change its size when it needs to, and add extra space in the bottom. Here is a demo project I threw together earlier. Download here
Profile pic
1) first you set the profile pic image center horizontal to the content view
2) set height and width for the profile pic
3)set top space constraints to content view
Change Profile pic label
1)set central horizontal to profile pic
2)set width and height
3)set vertical space between profile pic
Challenges Accepted label
1) set vertical space to profile pic label
2) set Leading space to container
3) set height
and do same for the below two content . i didnt tested. check it and try
After a long night of struggling, I figured out what I needed to do. I was setting the individual view controllers to have a simulated size of 4.7inch. This made it hard for the constraints to scale across all devices since I was setting the constraints for a specific screen size. However, this would be the way to go if using size classes.
I solved my issue by using the standard 600 X 600 canvas that is available before choosing a specific size. This way, I was able to set constraints that scaled down for the smaller screens, and scaled up for the larger/HD screens. This works perfectly with auto-layout. Hope that helps someone!
I added a tableview to a uiview in Storyboard and am having trouble getting the cell to be the right size. It is currently unusually large as a result of my trying to resize the tableview to fit the uiview. Can anyone tell me how to resize the cell (The upper handle is not visible and the dimensions are disabled in size inspector) and also why it the screen has a section in white in the middle...What is the white relative to the grey?
I want to set the content view of a scrollview to whatever the current screen size is, but AutoLayout is doing some funky stuff. This is trivial in code... just create a scrollview with a frame that is the superview's bounds. Then create a content view with the scrollview bounds and populate it and set the alwaysBounces... properties to YES. In interface builder though, this is some kind of sinful thing it seems.
I know Autolayout handles scrollviews totally differently because it wants to infer the content size based on constraints. My approach that failed is setting the scrollview to have 0 distance to its superview (all sides attached). Then, the same with the content view (the single scrollView subview)- attached to all superview edges. Then the precompiler thing complains about not knowing the content size, so I set a width and height constraint at placeholder to be removed at build time. But the result is a (CGRect){0,0,0,0} contentView. The 0 space to trailing edge and bottom of superview are totally ignored.
So how can I make a scrollview with a dynamic content size based on the screen size?
Bonus points if you can explain how you would do the same, but for a content size of 2x screen width.
You can try setting a constraint for the content view's width to equal the scroll view's width (for your bonus question: with a multiplier of 2). Same for height.
Not sure what the point of having a scroll view whose content is always the size of the scroll view is. By definition it wouldn't scroll, right?
At the moment the UIView is set to scale to fit. Is there any way of setting it to fill the whole element and set it to centre?
There is a content scale mode called aspect fill maybe does what you want.
I have an NSImageView that encloses a dynamically generated NSImage. When I change the image displayed, I would like to dynamically resize the NSImageView so that it precisely wraps the new image, and also have the enclosing window resize so that the space between the NSImageView and every other part of the window remains constant. (Note that the image view's scaling is set to none, as I want its image to always be shown at its physical size.) To illustrate, suppose I begin with a small image in my image view. If I replace it with a large image, I wish for both the NSImageView and enclosing window to resize to accommodate it, without affecting the sizing or spacing of any other element.
Currently, I call the following method whenever the magnification level is changed via the stepper or associated text field. Though regenerating the image and loading it into the NSImageView works fine, resizing the NSImageView and enclosing window do not.
- (void) updateMagnification:(NSUInteger)newMagnification {
// Keep values of stepper and associated text field synchronized.
[self.magnificationStepper setIntegerValue:newMagnification];
[self.magnificationTextField setIntegerValue:newMagnification];
// Regenerate image based on newMagnification and display in image view.
[self.qrGenerator generateWithBlockPixelWidth:newMagnification];
self.imageView.image = self.qrGenerator.image;
// Adjust frame size of image view.
NSLog(#"Old size: frame=%# image=%#", NSStringFromSize(self.imageView.frame.size), NSStringFromSize(self.imageView.image.size));
[self.imageView setFrameSize:NSMakeSize(self.imageView.image.size.width, self.imageView.image.size.height )];
NSLog(#"New size: frame=%# image=%#", NSStringFromSize(self.imageView.frame.size), NSStringFromSize(self.imageView.frame.size));
//[self.window setViewsNeedDisplay:YES];
//[self.imageView setNeedsDisplay:YES];
//[self.imageView.superview setNeedsDisplay:YES];
}
Regardless of whether I increase or decrease the magnification value, causing the image to grow smaller or larger, the size of both the NSImageView and window remains constant. The three setNeedsDisplay: calls that are commented out have no effect even if they're uncommented -- they were my attempt to determine if the problem was related to the controls not redrawing once their size was adjusted, but the calls had no effect. Curiously, my NSLog calls indicate that the imageView's frame does indeed take the requested size, for they yield this output:
2012-06-12 11:02:50.651 Presenter[4660:603] Old size: frame={422, 351} image={168, 168}
2012-06-12 11:02:50.651 Presenter[4660:603] New size: frame={168, 168} image={168, 168}
The actual display, of course, does not change.
Interestingly, changing the imageView's frame style to "none," either in Interface Builder or programatically with [self.imageView setImageFrameStyle:NSImageFrameNone], gives me behaviour closer to what I desire. Making the image larger so that it would otherwise be clipped by the image view does indeed result in the image view and window growing larger. From this point, however, making the image smaller does not result in the image view or window resizing accordingly. "None" is the only image frame style that displays this somewhat correct behaviour -- all four of the bordered styles (i.e., bevel [which is the default], button, groove, and photo) show the same entirely incorrect behaviour described above.
I came across someone with a similar problem. Oddly, he only observed the problematic behaviour when his image view's frame style was set to NSImageFrameNone, when this is the only value that gives me somewhat-correct behaviour. I tried modifying the frame style to a non-none value before the resize and to none afterward, as this resolved the other person's problem, but for me, this yielded the same behaviour as when I simply set the frame style to "none" initially.
Any help you provide will be much appreciated. Thanks!