[Solution] [technology] 22 tips for iOS development

[Solution] [technology] 22 tips for iOS development

1. What should I do if no Cell is displayed in TableView?

Similar to Figure 1, I don't want to display the empty ones below. It's easy to add "self. tableView. tableFooterView = [[UIView alloc] init];". After trying this sentence, it will look like Figure 2.

2. The custom leftBarbuttonItem left slide returned gesture is invalid. What should I do?

 

Self. navigationItem. leftBarButtonItem = [[UIBarButtonItemalloc] initWithImage: img style: Custom target: self action: @ selector (onBack :)]; self. navigationController. login. delegate = (id ) Self;

 

3. Why can't ScrollView be switched to the top of viewController?

 

Self. automaticallyAdjustsScrollViewInsets = NO;

 

4. What should I do if I want to throw my keyboard when writing a keyboard event?

 

• Buy a strong keyboard; Use IQKeyboardManager (search on GitHub). After use, the waist will not hurt, and the legs will not be sour.

   

  5. Why is there a problem with my apps?

  This artifact is called:KMCGeigerCounter, Go to GitHub.

  6. How can I adjust the separaLine position without creating a Cell?

   

  _ MyTableView. separatorInset = UIEdgeInsetsMake (0,100 );

   

  7. How can I click self. view to collapse the keyboard? Do I need to add a tapGestures?

   

  -(Void) touchesBegan :( NSSet *) toucheswithEvent :( UIEvent *) event {[self. viewendEditing: YES];}

   

  8. How to set the Default background image for each ViewController?

  Use the base class.

  9. I want to change the layoutAttributes added in xib in the code, but how can I find it using the code?

  Nslayoutattribute can also be used to pull your constraints like a Button.

  10. How can I hide the navigationbar when sliding like Safari?

   

  NavigationController. hidesBarsOnSwipe = Yes

   

  11. The title of the navigation bar's return key is so annoying. How can I make it disappear?

   

  View plaincopy [[UIBarButtonItemappearance] setBackButtonTitlePositionAdjustment: UIOffsetMake (0,-60) forBarMetrics: UIBarMetricsDefault];

   

  12. CoreData is so annoying to use. What should I do if the syntax is smelly and long?

  MagicRecord

  13. How does CollectionView implement the hovering header of tableview?

  CSStickyHeaderFlowLayout

  14. Can I use only one pan gesture to replace all directions of UISwipegesture?

   

  -(Void) pan :( UIPanGestureRecognizer *) sender {typedefNS_ENUM (NSUInteger, UIPanGestureRecognizerDirection) {average, minimum, minimum, and maximum}; switch (sender. state) {caseUIGestureRecognizerStateBegan: {if (direction = uipangesturerecognizerdiredireundefined) {CGPointvelocity = [sendervelocityInView: recognizer. view]; BOOLisVerticalGesture = fabs (velocity. y)> fabs (velocity. x); if (isVerticalGesture) {if (velocity. y> 0) {direction = UIPanGestureRecognizerDirectionDown;} else {direction = UIPanGestureRecognizerDirectionUp;} else {if (velocity. x> 0) {direction = uipangesturerecognizerdireright;} else {direction = direction ;}} break ;}:{ switch (direction) {direction: {[selfhandleUpwardsGesture: sender]; break;} condition: {[condition: sender]; break;} condition: {[selfhandleLeftGesture: sender]; break;} condition: {[selfhandleRightGesture: sender]; break ;} default: {break ;}} break ;}caseuigesturerecognizerstateended: {direction = uipangesturerecognizerdireundefined; break;} default: break ;}}

   

  15. How can I make the image not deformed when stretching the image?

  Method 1:

   

  UIImage * image = [[UIImageimageNamed: @ "xxx"] stretchableImageWithLeftCapWidth: 10 topCapHeight: 10];

   

  Note: A developer reminds me that this application has been disabled. The current method is resizableImageWithCapInsets.

  Method 2,

  16. Why is there a better library when playing GIF videos?

  FlipBoardFLAnimatedImageThat's perfect for you.

  17. How can I add pull-up refresh in one sentence?

  Use the SVPullToRefresh Library:

   

  [Dependencies: ^ {// prependdatatodataSource, insertcellsattopoftableview // call [tableView. pullToRefreshViewstopAnimating] whendone} position: SVPullToRefreshPositionBottom];

   

  18. How can I change the Cell color in tableview to another color?

   

  _ MTableView. tintColor = [UIColorredColor];

   

  19. Originally, my statusbar was lightcontent. Using UIImagePickerController will make my statusbar style black. What should I do?

   

  -(Void) navigationController :( UINavigationController *) navigationControllerwillShowViewController :( UIViewController *) viewControlleranimated :( BOOL) animated {[[UIApplicationsharedApplication] setStatusBarStyle: Custom];}

   

  20. How can I make my navigationbar transparent instead of blurred?

   

  [Self. navigationBarsetBackgroundImage: [UIImagenew] forBarMetrics: UIBarMetricsDefault]; self. navigationBar. shadowImage = [UIImagenew]; self. navigationBar. translucent = YES;

   

  21. How can I change the color and position of uitextfield placeholder?

  Inherit uitextfield and override this method:

   

  -(Void) Configure :( CGRect) rect {[UIColorblueColor] setFill]; [self. placeholderdrawInRect: rectwithFont: self. fontlineBreakMode: Signature: self. textAlignment];}

   

  22. Why do you know so many strange tricks?

  Click Stack Overflow!