uikit

问题 I have a UIButton defined within a tableviewCellWithReuseIdentifier. The button works but it's very touchy. If I just tap the button it works. Pressing it any long fails to trigger the action, even though it does flash showing that it knows it was pressed. Why is this happening? More importantly, how can I fix it. Here is the code for the UIButton within the cell. CGRect rect = CGRectMake(190.0, 2.0, 40.0, ROW_HEIGHT); UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];

问题 I have a UIScrollView filled with subviews, all is well when creating it and initially filling it. But when I add a new subview that is positionned outside of the visible screen portion, or when I just resize an existing subview that is also outside of the visible screen portion, there is a subsequent 0.3s-long scroll animation (I can see it happening from my delegate) that seems to match the newly added/resized element. Attempts: pagingEnabled is always NO. Setting scrollEnabled to NO during

问题 I'm currently using a UIDocumentInteractionController for open in functionality. When it opens it shows a list of all apps on the device that can handle that file type. Is there a way to disable my app sending a document to specific apps, even if they support that file type? For example - if I have a PDF file open in my app and iBooks is on the iPad, if I tap the iBooks icon in the UIDocumentInteractionController, I don't want it to send it to the app. Ideally - I see this as building a

问题 I don't want the drop shadow when the UIPopoverController's view appears. Is there a way to remove this drop shadow look? 回答1: Not straight forward, but since iOS 5, you can make your own custom popover background using UIPopoverBackgroundView. See the answer for this question: Using UIPopoverBackgroundView class. It's pointing to a good tuto. Then, in the initWithFrame of your UIPopoverBackgroundView implementation, you can use a clearColor for the drop shadow. Using offset and radius did

问题 I am following this tutorial for my doodle application. http://www.raywenderlich.com/18840/how-to-make-a-simple-drawing-app-with-uikit his erase function is using white color drawing. But I am using image background and when I erase, I really need to erase. I have tried CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeClear); But it's not working. Here is my code: - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { _mouseSwiped = NO; UITouch *touch = [touches

问题 I'm struggling with a pdf export method that's was running just fine until I ported the app to the arm64 achitecture. Bacisally, the method opens an existing PDF, it creates a new pdf file, and draws the content of the first pdf into the newly created one before adding more content pages. When the method tries to create a new pdf page to the document (after the first pdf was integrated to the new pdf) the app crashes with a EXC_BAD_ACCESS warning on UIGraphicsBeginPDFPage(); call . It only

问题 I have path stored in an array of CGPoints which I'd like to move an image along. Here's the general code I have so far: -(void)movePic:(id)sender{ for(int i = 0; i < self.array.count; i++){ CGPoint location = [[self.array objectAtIndex:i] CGPointValue]; [UIView animateWithDuration:0.1 animations:^{ self.imageView.center = location; } completion:^(BOOL finished){ }]; } } The problem is the for loop runs extremely fast, so you only see the animation on the last points. I'm unsure of how to

问题 I've created a custom container view controller using the new UIViewController container view controller methods in iOS 5. Trouble is, even though my container controller's child UIViewController has definesPresentationContext = YES, when it creates and presents another modal view controller, UIKit sets the container (rather than the child) as the presenting controller. For example, in MyChildViewController.m: - (void)showMailComposeView:(id)sender { __block MFMailComposeViewController *vc =

问题 Perhaps one Iphone Guru can enlighten me... I've been going line-by-line and eliminating any threads calls / NSInvocation's that use the UIKit, as a matter of fact, I have made 100% sure that NO UIKit crap gets called from any-where else except the MainThread I.E... if([NSThread isMainThread]) { blah.... Call UIKit Crap here! and blah.... } So far so good, but then after I created a thread to do a http POST (using LibCurl) I started getting this: "void _WebThreadLockFromAnyThread(bool),

问题 Xcode / objective c does not really print a useful stack trace. My app crashes somewhere, and the damn thing gives me only numbers like 45353453, 34524323, 6745345353, 457634524234. Not useful at all. So I want to make a NSLog(); on the beginning of EVERY method I have in my entire app. But maybe there's a simpler way to just find out the real stack trace, humanly readable? Not only on app launch or crash, but all the time, on every activity that happens? Would help debugging a lot. 回答1: