Bits of knowledge，bitsofknowledge

Bits of knowledge，bitsofknowledge
如何擷取當前裝置的系統版本！！！ 
[[[UIDevice currentDevice] systemVersion] floatValue] 
擷取App版本
NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; 
  // app名稱
    //NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"];
    
    // app build版本
    //NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"];
    
    // app版本
    NSString *app_Version = [infoDictionary objectForKey:@"CFBundleShortVersionString"];

如何更改導航控制器push動畫時間？   
 A控制器push到B控制器,push動畫過渡時間大約為0.3秒。希望改成0.7秒！ pop出來也改成0.7秒！請問該如何?？ 
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (self.viewControllers.count > 0) {

        viewController.hidesBottomBarWhenPushed = YES;
        CATransition *animation = [CATransition animation];
        animation.duration = 0.5f;
        animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
        animation.type = kCATransitionPush;
        animation.subtype = kCATransitionFromRight;
        [self.navigationController.view.layer addAnimation:animation forKey:nil];
        [super pushViewController:viewController animated:NO];
        return;
    }
    [super pushViewController:viewController animated:YES];
}

iOS介面設定豎屏，個別介面強制橫屏   
- (BOOL)shouldAutorotate 當前viewcontroller是否支援轉屏


- (NSUInteger)supportedInterfaceOrientations；當前viewcontroller支援哪些轉屏方向 -(UIInterfaceOrientation)preferredInterfaceOrientationForPresentation當前viewcontroller預設的螢幕方向 

 

#import <UIKit/UIKit.h> @interface CustomNavigationController : UINavigationController @property(nonatomic)NSUInteger orietation;      #import "CustomNavigationController.h" @interface CustomNavigationController () @end @implementation CustomNavigationController - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {     self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];     if (self) {     }     return self; } - (void)viewDidLoad {     [super viewDidLoad];     // Do any additional setup after loading the view. } - (void)didReceiveMemoryWarning {     [super didReceiveMemoryWarning];     // Dispose of any resources that can be recreated. } //當前viewcontroller是否支援轉屏 -(BOOL)shouldAutorotate {     return NO;      } //當前viewcontroller支援哪些轉屏方向 -(NSUInteger)supportedInterfaceOrientations{     //return UIInterfaceOrientationMaskLandscapeRight;     return self.orietation; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {     return (interfaceOrientation != self.orietation); }

 

iOS推崇使用png格式的 說這樣不會失幀
imageWithContentsOfFile這個方法？跟imagewithname的區別嗎
imagewithname會使用系統緩衝，對重複載入的圖片速度會快。效果好 
imageWithContentsOfFile不會緩衝


小圖 用 imageName  大圖 還有 做動畫的圖片 使用imageWithContentsOfFile