Small and iOS knowledge points in iOS

Small and iOS knowledge points in iOS

1. Hide the scroll bar in tableView

   self.tableView.showsVerticalScrollIndicator = NO;

2. About attributes

Use assign: Use copy for basic data types (NSInteger, CGFloat) and C data types (int, float, double, char, etc.): Use retain (strong) for NSString ): for other NSObject and its subclass 3. register cell

// Register cell [self. tableView registerNib: [UINib nibWithNibName: NSStringFromClass ([DDZRecommendCategoryCell class]) bundle: nil] forCellReuseIdentifier: @ "category"];

 

4. Reuse cell

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"category"];

 

5. Refresh the page

        [self.tableView reloadData];

Generally, the update display function is used after the server data is requested.

 

6. appearance uniformly sets the appearance

// Set NSMutableDictionary * attrs = [NSMutableDictionary dictionary] In appearance; attrs [dictionary] = [UIFont systemFontOfSize: 13]; attrs [interval] = [UIColor grayColor]; // set the appearance of item (condition: UI_APPEARANCE_SELECTOR is followed by the method) UITabBarItem * item = [UITabBarItem appearance]; [item setTitleTextAttributes: attrs forState: UIControlStateNormal]

 

7. Use your custom tabbar

// Change the tabBar (use KVC to directly change the member variable) [self setValue: [[DDZTabBar alloc] init] forKey: @ "tabBar"];

In your tabber class

Use-(void) layoutSubviews to adjust the position of the internal subview

 

8. Make your code called only once

For example, appearance can be set once.

+ (void)initialize

 

9. The first line is selected by default in tableView.

// By default, the first line [self. tableView selectRowAtIndexPath: [NSIndexPath indexPathForRow: 0 inSection: 0] animated: NO scrollPosition: UITableViewScrollPositionTop] is selected.

 

10. Set insert (the displayed content is blocked in the navigation bar of UITbaleView)

// Set insert self. automaticallyAdjustsScrollViewInsets = NO; self. tableView. contentInset = UIEdgeInsetsMake (64, 0, 0, 0 );

 

11. Set the cell height (the default cell height is 44)

self.tableView.rowHeight = 70;