不同iOS設備的圖像大小

Question

我是iOS編程新手。我想問這些關於不同屏幕尺寸的圖像大小的問題

1. 對於所有iOS設備，x，2x和3x圖像大小是否足夠？我的意思是，如果我有一個名爲「background.png」的圖像，background.png，background2x.png和background3x.png是否足以適用於所有iOS設備/屏幕尺寸？
2. 如果不是，不同的iPad型號是否需要其他圖像尺寸（x，2x和3x除外）？ .......一個解釋不同的屏幕尺寸/設備的圖像大小的鏈接將不勝感激。由於

Answer 1

是X，2倍和3個的圖像尺寸是必要的開發應用爲所有iOS設備，但圖像的尺寸可以爲iPad & iPhone設備不同，這取決於iPad的& iPhone應用程序的用戶界面。

爲背景圖片更好的理解，請看看Adaptivity and Layout

一個與您查詢的最佳文章 - Adaptive Layout Tutorial in iOS 9: Getting Started

Answer 2

如果您對@ 1倍，@ 2X形成的圖像，並@ 3倍，名稱他們是這樣的：

• iPhone 3：myImage.png
• iPhone 4，4S：myImage@2x.png
• iPhone 5，5S：myImage-568h@2x.png
• iPhone 6，6S：myImage-667h@2x.png
• iPhone 6P，6PS：myImage-736h@3x.png

然後，你可以調用像吹製法：

UIImage *myImage = [self deviceSizedImageWithName:@"myImage.png"];

#define kScreenHeight [UIScreen mainScreen].bounds.size.height 
#define kScreenWidth [UIScreen mainScreen].bounds.size.width 
#define kScreenSize [UIScreen mainScreen].bounds.size 
#define IS_IPAD (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) 
#define IS_IPHONE (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) 
#define IS_IPHONE_4 (IS_IPHONE && kScreenHeight == 480.0f) 
#define IS_IPHONE_5 (IS_IPHONE && kScreenHeight == 568.0f) 
#define IS_IPHONE_6 (IS_IPHONE && kScreenHeight == 667.0f) 
#define IS_IPHONE_6P (IS_IPHONE && kScreenHeight == 736.0f) 

- (UIImage *)deviceSizedImageWithName:(NSString *)imageNamed 
{ 
    NSString *imgExtension = [imageNamed pathExtension]; 
    NSString *imgName = [imageNamed stringByReplacingOccurrencesOfString:[NSString stringWithFormat:@".%@", imgExtension] withString:@""]; 

    BOOL removedExt = [imgExtension length]; 

    UIImage *image = [UIImage imageNamed:imageNamed]; 
    if (IS_IPHONE_5) { 
     if (removedExt) image = [UIImage imageNamed:[NSString stringWithFormat:@"%@-568h.%@", imgName, imgExtension]]; 
     else image = [UIImage imageNamed:[NSString stringWithFormat:@"%@-568h", imageNamed]]; 

     if (!image) return [UIImage imageNamed:imageNamed]; 

    } else if (IS_IPHONE_6) { 
     if (removedExt) image = [UIImage imageNamed:[NSString stringWithFormat:@"%@-667h.%@", imgName, imgExtension]]; 
     else image = [UIImage imageNamed:[NSString stringWithFormat:@"%@-667h", imageNamed]]; 

     if (!image) return [UIImage imageNamed:imageNamed]; 

    } else if (IS_IPHONE_6P) { 
     if (removedExt) image = [UIImage imageNamed:[NSString stringWithFormat:@"%@-736.%@", imgName, imgExtension]]; 
     else image = [UIImage imageNamed:[NSString stringWithFormat:@"%@-736", imageNamed]]; 

     if (!image) return [UIImage imageNamed:imageNamed]; 

    } 
    return image; 
}