102

我正在使用 Xcode 5 的资产目录，我想使用我LaunchImage的作为我的主视图的背景图像（一种非常常见的做法，可以使从“加载”到“加载”的过渡看起来平滑）。

我想在资产目录中使用相同的条目来节省空间，而不必在两个不同的图像集中复制图像。

但是，调用：

UIImage *image = [UIImage imageNamed:@"LaunchImage"]; //returns nil
4

14 回答 14

83

这是 LaunchImage 的（几乎）完整列表（不包括没有状态栏的 iPad 图像）：

  • LaunchImage-568h@2x.png
  • LaunchImage-700-568h@2x.png
  • LaunchImage-700-Landscape@2x~ipad.png
  • LaunchImage-700-Landscape~ipad.png
  • LaunchImage-700-Portrait@2x~ipad.png
  • LaunchImage-700-Portrait~ipad.png
  • LaunchImage-700@2x.png
  • LaunchImage-Landscape@2x~ipad.png
  • LaunchImage-横向~ipad.png
  • LaunchImage-Portrait@2x~ipad.png
  • LaunchImage-Portrait~ipad.png
  • 启动图像.png
  • LaunchImage@2x.png
  • LaunchImage-800-667h@2x.png (iPhone 6)
  • LaunchImage-800-Portrait-736h@3x.png (iPhone 6 Plus 纵向)
  • LaunchImage-800-Landscape-736h@3x.png（iPhone 6 Plus 横向）
  • LaunchImage-1100-Portrait-2436h@3x.png (iPhone X 纵向)
  • LaunchImage-1100-Landscape-2436h@3x.png（iPhone X 横向）
于 2013-11-18T10:11:27.287 回答
67 
- (NSString *)splashImageNameForOrientation:(UIInterfaceOrientation)orientation {
    CGSize viewSize = self.view.bounds.size;
    NSString* viewOrientation = @"Portrait";
    if (UIDeviceOrientationIsLandscape(orientation)) {
        viewSize = CGSizeMake(viewSize.height, viewSize.width);
        viewOrientation = @"Landscape";
    }

    NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
    for (NSDictionary* dict in imagesDict) {
        CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
        if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
            return dict[@"UILaunchImageName"];
    }
    return nil;
}
于 2015-01-06T11:43:28.790 回答
52

The LaunchImages are special, and aren't actually an asset catalog on the device. If you look using iFunBox/iExplorer/etc (or on the simulator, or in the build directory) you can see the final names, and then write code to use them - eg. for an iOS7-only iPhone-only project, this will set the right launch image:

NSString *launchImage;
if  ((UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) &&
     ([UIScreen mainScreen].bounds.size.height > 480.0f)) {
    launchImage = @"LaunchImage-700-568h";
} else {
    launchImage = @"LaunchImage-700";
}

[self.launchImageView setImage:[UIImage imageNamed:launchImage]];

I put this into viewDidLoad.

This isn't really ideal, it would be great if Apple would give us a nice API to do this.

于 2013-10-09T16:05:15.240 回答
27

我的应用目前仅支持 iOS 7 及更高版本。

这就是我从资产目录中引用启动图像的方式：

NSDictionary *dict = @{@"320x480" : @"LaunchImage-700",
                       @"320x568" : @"LaunchImage-700-568h",
                       @"375x667" : @"LaunchImage-800-667h",
                       @"414x736" : @"LaunchImage-800-Portrait-736h"};
NSString *key = [NSString stringWithFormat:@"%dx%d",
    (int)[UIScreen mainScreen].bounds.size.width,
    (int)[UIScreen mainScreen].bounds.size.height];
UIImage *launchImage = [UIImage imageNamed:dict[key]];

如果你想支持旧的 iOS 版本，你可以添加更多的键值对。

于 2014-09-15T21:05:21.820 回答
10

这是基于上面 Cherpak Evgeny 提供的解决方案的 UIImage 类别。

UIImage+SplashImage.h：

#import <UIKit/UIKit.h>

/**
 * Category on `UIImage` to access the splash image.
 **/
@interface UIImage (SplashImage)

/**
 * Return the name of the splash image for a given orientation.
 * @param orientation The interface orientation.
 * @return The name of the splash image.
 **/
+ (NSString *)si_splashImageNameForOrientation:(UIInterfaceOrientation)orientation;

/**
 * Returns the splash image for a given orientation.
 * @param orientation The interface orientation.
 * @return The splash image.
 **/
+ (UIImage*)si_splashImageForOrientation:(UIInterfaceOrientation)orientation;

@end

UIImage+SplashImage.m：

#import "UIImage+SplashImage.h"

@implementation UIImage (SplashImage)

+ (NSString *)si_splashImageNameForOrientation:(UIInterfaceOrientation)orientation
{
    CGSize viewSize = [UIScreen mainScreen].bounds.size;

    NSString *viewOrientation = @"Portrait";

    if (UIDeviceOrientationIsLandscape(orientation))
    {
        viewSize = CGSizeMake(viewSize.height, viewSize.width);
        viewOrientation = @"Landscape";
    }

    NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];

    for (NSDictionary *dict in imagesDict)
    {
        CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
        if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
            return dict[@"UILaunchImageName"];
    }
    return nil;
}

+ (UIImage*)si_splashImageForOrientation:(UIInterfaceOrientation)orientation
{
    NSString *imageName = [self si_splashImageNameForOrientation:orientation];
    UIImage *image = [UIImage imageNamed:imageName];
    return image;
}

@end
于 2015-01-22T17:16:45.167 回答
9

@codeman 为 Swift 1.2 更新的答案：

func splashImageForOrientation(orientation: UIInterfaceOrientation, size: CGSize) -> String? {
    var viewSize        = size
    var viewOrientation = "Portrait"

    if UIInterfaceOrientationIsLandscape(orientation) {
        viewSize        = CGSizeMake(size.height, size.width)
        viewOrientation = "Landscape"
    }

    if let imagesDict = NSBundle.mainBundle().infoDictionary as? [String: AnyObject] {
        if let imagesArray = imagesDict["UILaunchImages"] as? [[String: String]] {
            for dict in imagesArray {
                if let sizeString = dict["UILaunchImageSize"], let imageOrientation = dict["UILaunchImageOrientation"] {
                    let imageSize = CGSizeFromString(sizeString)
                    if CGSizeEqualToSize(imageSize, viewSize) && viewOrientation == imageOrientation {
                        if let imageName = dict["UILaunchImageName"] {
                            return imageName
                        }
                    }
                }
            }
        }
    }

    return nil

}

调用它并支持 iOS 8 的旋转：

override func viewWillAppear(animated: Bool) {
    if let img = splashImageForOrientation(UIApplication.sharedApplication().statusBarOrientation, size: self.view.bounds.size) {
        backgroundImage.image = UIImage(named: img)
    }
}

override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
    let orientation = size.height > size.width ? UIInterfaceOrientation.Portrait : UIInterfaceOrientation.LandscapeLeft

    if let img = splashImageForOrientation(orientation, size: size) {
        backgroundImage.image = UIImage(named: img)
    }

}

正是我需要的，谢谢！

于 2015-04-22T09:08:26.287 回答
7

我刚刚写了一个通用方法来获取 iPhone 和 iPad 的启动图像名称（横向、纵向），它对我有用，希望它也能帮助你。我在其他 SO 答案的帮助下写了这个，感谢@Pichirichi 的整个列表。

+(NSString*)getLaunchImageName
{

 NSArray* images= @[@"LaunchImage.png", @"LaunchImage@2x.png",@"LaunchImage-700@2x.png",@"LaunchImage-568h@2x.png",@"LaunchImage-700-568h@2x.png",@"LaunchImage-700-Portrait@2x~ipad.png",@"LaunchImage-Portrait@2x~ipad.png",@"LaunchImage-700-Portrait~ipad.png",@"LaunchImage-Portrait~ipad.png",@"LaunchImage-Landscape@2x~ipad.png",@"LaunchImage-700-Landscape@2x~ipad.png",@"LaunchImage-Landscape~ipad.png",@"LaunchImage-700-Landscape~ipad.png"];

UIImage *splashImage;

if ([self isDeviceiPhone])
{
    if ([self isDeviceiPhone4] && [self isDeviceRetina])
    {
        splashImage = [UIImage imageNamed:images[1]];
        if (splashImage.size.width!=0)
            return images[1];
        else
            return images[2];
    }
    else if ([self isDeviceiPhone5])
    {
        splashImage = [UIImage imageNamed:images[1]];
        if (splashImage.size.width!=0)
            return images[3];
        else
            return images[4];
    }
    else
        return images[0]; //Non-retina iPhone
}
else if ([[UIDevice currentDevice] orientation]==UIDeviceOrientationPortrait || [[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown)//iPad Portrait
{
    if ([self isDeviceRetina])
    {
        splashImage = [UIImage imageNamed:images[5]];
        if (splashImage.size.width!=0)
            return images[5];
        else
            return images[6];
    }
    else
    {
        splashImage = [UIImage imageNamed:images[7]];
        if (splashImage.size.width!=0)
            return images[7];
        else
            return images[8];
    }

}
else
{
    if ([self isDeviceRetina])
    {
        splashImage = [UIImage imageNamed:images[9]];
        if (splashImage.size.width!=0)
            return images[9];
        else
            return images[10];
    }
    else
    {
        splashImage = [UIImage imageNamed:images[11]];
        if (splashImage.size.width!=0)
            return images[11];
        else
            return images[12];
    }
 }
}

其他实用方法是

+(BOOL)isDeviceiPhone
{
 if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
 {
     return TRUE;
 }

 return FALSE;
}

+(BOOL)isDeviceiPhone4
{
 if ([[UIScreen mainScreen] bounds].size.height==480)
    return TRUE;

 return FALSE;
}


+(BOOL)isDeviceRetina
{
 if ([[UIScreen mainScreen] respondsToSelector:@selector(displayLinkWithTarget:selector:)] &&
    ([UIScreen mainScreen].scale == 2.0))        // Retina display
 {
    return TRUE;
 } 
 else                                          // non-Retina display
 {
     return FALSE;
 }
}


+(BOOL)isDeviceiPhone5
{
 if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone && [[UIScreen mainScreen] bounds].size.height>480)
 {
    return TRUE;
 }
 return FALSE;
}
于 2014-04-30T06:09:03.737 回答
7

Cherpak Evgeny 回答的 Swift 版本：

    func splashImageForOrientation(orientation: UIInterfaceOrientation) -> String {
        var viewSize = self.view.bounds.size
        var viewOrientation = "Portrait"
        if UIInterfaceOrientationIsLandscape(orientation) {
           viewSize = CGSizeMake(viewSize.height, viewSize.width)
           viewOrientation = "Landscape"
        }
        let imagesDict = NSBundle.mainBundle().infoDictionary as Dictionary<NSObject,AnyObject>!
        let imagesArray = imagesDict["UILaunchImages"] as NSArray
        for dict in imagesArray {
            let dictNSDict = dict as NSDictionary
            let imageSize = CGSizeFromString(dictNSDict["UILaunchImageSize"] as String)
            if CGSizeEqualToSize(imageSize, viewSize) && viewOrientation == (dictNSDict["UILaunchImageOrientation"] as String) {
                return dictNSDict["UILaunchImageName"] as String
            }
        }
        return ""
    }
于 2015-02-19T19:56:36.903 回答
5

在@Pichirich 的回答之后，我在 InterfaceBuilder 中引用了我的启动图像：

“启动图像.png”

...在 Xcode 5.0.2 中，它会自动从资产目录中直接提取适当的图像。

这是我所期望的——除了苹果公司将“Default.png”静默重命名为“LaunchImage.png”的恶毒举动:)

于 2013-11-20T12:40:00.300 回答
3

只需一行代码即可轻松访问 Launch 图像。

 UIImage *myAppsLaunchImage = [UIImage launchImage];

请按照下面给出的步骤来实现上述功能。

步骤 1.UIImage通过创建类别来扩展

+ (UIImage *)launchImage {
    NSDictionary *dOfLaunchImage = [NSDictionary dictionaryWithObjectsAndKeys:
                                    @"LaunchImage-568h@2x.png",@"568,320,2,8,p", // ios 8 - iphone 5 - portrait
                                    @"LaunchImage-568h@2x.png",@"568,320,2,8,l", // ios 8 - iphone 5 - landscape
                                    @"LaunchImage-700-568h@2x.png",@"568,320,2,7,p", // ios 7 - iphone 5 - portrait
                                    @"LaunchImage-700-568h@2x.png",@"568,320,2,7,l", // ios 7 - iphone 5 - landscape
                                    @"LaunchImage-700-Landscape@2x~ipad.png",@"1024,768,2,7,l", // ios 7 - ipad retina - landscape
                                    @"LaunchImage-700-Landscape~ipad.png",@"1024,768,1,7,l", // ios 7 - ipad regular - landscape
                                    @"LaunchImage-700-Portrait@2x~ipad.png",@"1024,768,2,7,p", // ios 7 - ipad retina - portrait
                                    @"LaunchImage-700-Portrait~ipad.png",@"1024,768,1,7,p", // ios 7 - ipad regular - portrait
                                    @"LaunchImage-700@2x.png",@"480,320,2,7,p", // ios 7 - iphone 4/4s retina - portrait
                                    @"LaunchImage-700@2x.png",@"480,320,2,7,l", // ios 7 - iphone 4/4s retina - landscape
                                    @"LaunchImage-Landscape@2x~ipad.png",@"1024,768,2,8,l", // ios 8 - ipad retina - landscape
                                    @"LaunchImage-Landscape~ipad.png",@"1024,768,1,8,l", // ios 8 - ipad regular - landscape
                                    @"LaunchImage-Portrait@2x~ipad.png",@"1024,768,2,8,p", // ios 8 - ipad retina - portrait
                                    @"LaunchImage-Portrait~ipad.png",@"1024,768,1,8,l", // ios 8 - ipad regular - portrait
                                    @"LaunchImage.png",@"480,320,1,7,p", // ios 6 - iphone 3g/3gs - portrait
                                    @"LaunchImage.png",@"480,320,1,7,l", // ios 6 - iphone 3g/3gs - landscape
                                    @"LaunchImage@2x.png",@"480,320,2,8,p", // ios 6,7,8 - iphone 4/4s - portrait
                                    @"LaunchImage@2x.png",@"480,320,2,8,l", // ios 6,7,8 - iphone 4/4s - landscape
                                    @"LaunchImage-800-667h@2x.png",@"667,375,2,8,p", // ios 8 - iphone 6 - portrait
                                    @"LaunchImage-800-667h@2x.png",@"667,375,2,8,l", // ios 8 - iphone 6 - landscape
                                    @"LaunchImage-800-Portrait-736h@3x.png",@"736,414,3,8,p", // ios 8 - iphone 6 plus - portrait
                                    @"LaunchImage-800-Landscape-736h@3x.png",@"736,414,3,8,l", // ios 8 - iphone 6 plus - landscape
                                    nil];
    NSInteger width = ([UIScreen mainScreen].bounds.size.width>[UIScreen mainScreen].bounds.size.height)?[UIScreen mainScreen].bounds.size.width:[UIScreen mainScreen].bounds.size.height;
    NSInteger height = ([UIScreen mainScreen].bounds.size.width>[UIScreen mainScreen].bounds.size.height)?[UIScreen mainScreen].bounds.size.height:[UIScreen mainScreen].bounds.size.width;
    NSInteger os = [[[[[UIDevice currentDevice] systemVersion] componentsSeparatedByString:@"."] objectAtIndex:0] integerValue];
    NSString *strOrientation = UIDeviceOrientationIsLandscape([[UIDevice currentDevice] orientation])?@"l":@"p";
    NSString *strImageName = [NSString stringWithFormat:@"%li,%li,%li,%li,%@",width,height,(NSInteger)[UIScreen mainScreen].scale,os,strOrientation];
    UIImage *imageToReturn = [UIImage imageNamed:[dOfLaunchImage valueForKey:strImageName]];
    if([strOrientation isEqualToString:@"l"] && [strImageName rangeOfString:@"Landscape"].length==0) {
        imageToReturn = [UIImage rotate:imageToReturn orientation:UIImageOrientationRight];
    }
    return imageToReturn;
}

第 2 步。上述方法应该通过将以下代码也添加到同一类别中来工作UIImage

static inline double radians (double degrees) {return degrees * M_PI/180;}

+ (UIImage *)rotate:(UIImage*)src orientation:(UIImageOrientation) orientation {
    UIGraphicsBeginImageContext(src.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    if (orientation == UIImageOrientationRight) {
        CGContextRotateCTM (context, radians(90));
    } else if (orientation == UIImageOrientationLeft) {
        CGContextRotateCTM (context, radians(-90));
    } else if (orientation == UIImageOrientationDown) {
        // NOTHING
    } else if (orientation == UIImageOrientationUp) {
        CGContextRotateCTM (context, radians(90));
    }
    [src drawAtPoint:CGPointMake(0, 0)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}
于 2014-11-21T11:12:19.963 回答
3

在文档中有明确说明：

“资产目录中的每个集合都有一个名称。您可以使用该名称以编程方式加载集合中包含的任何单个图像。要加载图像，请调用UIImage:ImageNamed:方法，传递包含图像的集合的名称。”

使用 Pichirich 的列表有助于解决这种不一致。

于 2014-04-25T18:56:34.800 回答
2

我意识到这不一定是每个人的最佳解决方案，但最简单（且最不容易出错，恕我直言）的方法是在您的 Images.xcassets 目录中创建一个单独的条目。我叫它SplashImage。

当您添加新条目时，请确保不要选择“新启动图像”作为选项。相反，选择通用的“新图像集”。接下来，打开检查器并选择相关选项。如果您只为视网膜设备构建，就像我一样，您可以选择以下内容：

图像检查器

这将为您留下四个条目（iPhone 4S、iPhone 5(s,c)、iPhone 6 和 iPhone 6 Plus）。

图片

图片对应的文件如下：

| Resolution (Xcode entry) | Launch Image name   |   Device         |
|--------------------------|---------------------|------------------|
| 1x                       | Default-750.png     | iPhone 6         |
| 2x                       | Default@2x.png      | iPhone 4S        |
| Retina 4 2x              | Default-568h@2x.png | iPhone 5, 5s, 5c |
| 3x                       | Default-1242.png    | iPhone 6 Plus    |

当然，完成此操作后，您可以简单地使用[UIImage imageNamed:@"SplashImage"]

于 2014-09-11T18:07:10.643 回答
2

在 Pichirich 的回答的帮助下，我实现了以下类别（iOS 7+）： UIImage+AssetLaunchImage

它实际上只是动态生成名称，但可能会有所帮助。

于 2014-11-26T18:59:20.040 回答
0

更新到最新的 Swift 语法 (Swift 5)

   func splashImageForOrientation(orientation: UIInterfaceOrientation) -> String? {

    var viewSize = screenSize
    var viewOrientation = "Portrait"
    if orientation.isLandscape {
        viewSize = CGSize(width: viewSize.height, height: viewSize.width)
        viewOrientation = "Landscape"
    }
    if let infoDict = Bundle.main.infoDictionary, let launchImagesArray = infoDict["UILaunchImages"] as? [Any] {
        for launchImage in launchImagesArray {
            if let launchImage = launchImage as? [String: Any], let nameString = launchImage["UILaunchImageName"] as? String, let sizeString = launchImage["UILaunchImageSize"] as? String, let orientationString = launchImage["UILaunchImageOrientation"] as? String {
                let imageSize = NSCoder.cgSize(for: sizeString)
                if imageSize.equalTo(viewSize) && viewOrientation == orientationString {
                    return nameString
                }
            }
        }
    }
    return nil
}
于 2019-04-15T10:55:57.350 回答