uikit

问题 I have a question dealing with UIButton and its hit area. I am using the Info Dark button in interface builder, but I am finding that the hit area is not large enough for some people's fingers. Is there a way to increase the hit area of a button either programmatically or in Interface Builder without changing the size of the InfoButton graphic? 回答1: Since I am using a background image, none of these solutions worked well for me. Here is a solution that does some fun objective-c magic and

问题 I followed this UIPopoverPresentationController on iPhone doesn't produce popover but doesn't produce popover on iphone. Here is the code of viewcontroller class ViewController:UIViewController,UIPopoverPresentationControllerDelegate{ override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. } override func prepare(for segue: UIStoryboardSegue, sender: Any?) { if segue.identifier == "second"{ let secondVC = segue.destination let controller :

问题 I am adding a simple UIView to my app. This works fine, until I use the 'transform' property to rotate it: myView = [[UIView alloc] initWithFrame:CGRectMake(50, 50, 100, 100)]; myView.backgroundColor = [UIColor whiteColor]; myView.transform = CGAffineTransformMakeRotation(-0.2); [self.view addSubview:myView]; //self.view is just another generic UIView The added view is rotated, but has jagged edges - i.e. the edges have not been anti-aliased. Here's an example of what I mean: aliased vs. anti

问题 I'm calling the following code from drawRect - (void) drawPartial:(UIImage *)img colour:(UIColor *)colour { CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSaveGState(context); CGContextTranslateCTM(context, 0.0, self.bounds.size.height); CGContextScaleCTM(context, 1.0, -1.0); CGContextDrawImage(context, self.frame, img.CGImage); if (colour!=nil) { CGContextSetBlendMode (context, kCGBlendModeColor ); CGContextClipToMask(context, self.bounds, img.CGImage); CGContextSetFillColor

问题 I'm calling the following code from drawRect - (void) drawPartial:(UIImage *)img colour:(UIColor *)colour { CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSaveGState(context); CGContextTranslateCTM(context, 0.0, self.bounds.size.height); CGContextScaleCTM(context, 1.0, -1.0); CGContextDrawImage(context, self.frame, img.CGImage); if (colour!=nil) { CGContextSetBlendMode (context, kCGBlendModeColor ); CGContextClipToMask(context, self.bounds, img.CGImage); CGContextSetFillColor

问题 I've been working with making a mobile app using Xamarin.Forms. I have everything working on android, but when I try to launch on iOS I get the error: System.Exception: Could not initialize an instance of the type 'UIKit.UIImage': the native 'initWithContentsOfFile:' method returned nil. >It is possible to ignore this condition by setting MonoTouch.ObjCRuntime.Class.ThrowOnInitFailure to false. .... Does anyone know how to solve this? Edit: Here is the code it gives me the error on, but I

问题 I have a full screen UIScrollView to display my image, which employ some codes from PhotoScroller.app from apple sample code. I am little confused on the obtaining of the center point of the imageScrollView's bounds. ImageScrollView.m - (CGPoint)pointToCenterAfterRotation { NSLog(@"imageScrollView frame X and Y are %f and %f ",self.frame.origin.x, self.frame.origin.y); NSLog(@"imageScrollView frame Width and Height are %f and %f ",self.frame.size.width, self.frame.size.height); NSLog(@

问题 I have an NSString like @"Hello World" and want to convert that into an bitmap with exactly 20 pixels height. The width of the bitmap should match the width of the text. I know there are some NSString UIKit additions that can draw text, but I don't know how to draw the text with an bounding box of exactly 20 pixels height (text fits perfectly into this height) into an bitmap that has the perfect size to carry the text? Is there an easy way to do this? This must also work with Chinese,

问题 I have an NSString like @"Hello World" and want to convert that into an bitmap with exactly 20 pixels height. The width of the bitmap should match the width of the text. I know there are some NSString UIKit additions that can draw text, but I don't know how to draw the text with an bounding box of exactly 20 pixels height (text fits perfectly into this height) into an bitmap that has the perfect size to carry the text? Is there an easy way to do this? This must also work with Chinese,

问题 In my app I have a scrollview and when I press a button it is hidden when I press again it shows up. I use scrollview.hidden = YES (or NO) to do it. But I want to do it with an animation. For example, it may disappear from the bottom of the screen by moving and shows up with the same way. How can I do that? edit: [UIView beginAnimations:@"myAnimation" context:nil]; CGRect Frame = bottomScroller.frame; if(Frame.origin.y == 380){ Frame.origin.y = 460; }else{ Frame.origin.y = 380; }