uikit

问题 Is there a way to adjust the position of a rightView on UITextField? I tried setting the frame on the view (set as rightView) but it didn't change anything. I'd like to avoid making two views, one as the rightView and one as the rightView's subview where I change the subview's position, if possible. 回答1: The right overlay view is placed in the rectangle returned by the rightViewRectForBounds : method of the receiver. So I suggest you subclass UITextField and override this method, something

问题 I'm trying to add circle border to a UIView with green background, I created simple UIView subclass with borderWidth, cornerRadius and borderColor properties and I'm setting it from storyboard. @IBDesignable class RoundedView: UIView { @IBInspectable var cornerRadius: CGFloat { get { return layer.cornerRadius } set { layer.cornerRadius = newValue layer.masksToBounds = newValue > 0 } } @IBInspectable var borderWidth: CGFloat { get { return layer.borderWidth } set { layer.borderWidth = newValue

问题 I'm trying to calculate the height of the text constrained by a UITextView but it doesn't seem to return correct results. Here is my code : - (void)textViewDidChange:(UITextView *)aTextView { CGSize textSize = [aTextView.text sizeWithFont:aTextView.font constrainedToSize:aTextView.frame.size lineBreakMode:UILineBreakModeWordWrap]; counter.text = [NSString stringWithFormat:@"%f", textSize.height]; } You can download the sample project and a short screencast that illustrates the problem (418 KB

问题 I try to change the color from a UIPopoverControler on iOS 5. To do so, I use a subclass of UIPopoverBackgroundView that I assign to my popover like this: self.popover.popoverBackgroundViewClass = [KWPopoverBackgroundView class]; My popover is now black as I defined in my KWPopoverBackgroundView class but I still have a problem with the appearance. The back button (Medals) of the navigationController inside my popover is still blue. I want everything unified in black. How do I get rid of this

问题 I've tried searching for this, but no luck, so hoping there are some guru's who may know the answer. I'm seeing loads of reports in iTunes Connect of my app crashing with a particular stack trace, but the stack trace reveals nothing useful. #0. Crashed: main 0 UIKit 0x1871100c0 __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 324 1 UIKit 0x1871100bc __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 320 2 UIKit 0x1870630c8

问题 such as the code: view.opaque = YES; and view.backgroundColor = [UIColor clearColor]; any one who can explain something about this? EDIT: as the document shows: Declare Views as Opaque Whenever Possible UIKit uses the opaque property of each view to determine whether the view can optimize compositing operations. Setting the value of this property to YES for a custom view tells UIKit that it does not need to render any content behind your view. Less rendering can lead to increased performance

问题 I am unable to change the prompt color on my navigation bar. I've tried the code below in viewDidLoad , but nothing happens. self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.white] Am I missing something? Is the code above wrong? 回答1: It seems like you're right about this one. You need to use UIAppearance to style the prompt text on iOS 11. I've filed radar #34758558 that the titleTextAttributes property just stopped working for

问题 I'm trying to draw image using UIImage 's drawInRect: method. Here is the code: UIImage *image = [UIImage imageNamed:@"OrangeBadge.png"]; UIGraphicsBeginImageContext(image.size); [image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)]; UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); The problem is that the resulting image is blurry. Here is the resulting image (on the right side) compared to the source image (on the left side):

问题 Imagine a UILabel, which is 200 pixels wide and 50 pixels high. The label has text inside, and the label makes the text smaller so that it fits into the label. But now, how would you get the size of that UIFont how it is visible in the label? Lets imagine the font size was given with huge 100, and the label squeezes it down to 15. And then, you want to make some other labels with little text, which has same font size. Is there a way to obtain the UIFont's font size after getting squeezed by

问题 I'm trying to ignore UITapGestureRecognizer taps on a UITableView with the following: - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch { if ([touch.view isKindOfClass:[UITableViewCellContentView class]]) { return NO; // ignore the touch } return YES; // handle the touch } It won't compile: "Use of undeclared identifier 'UITableViewCellContentView' Undocumented class? Need to subclass? Better way to accomplish this? Thanks for any help. 回答1