如何从 info.plist 中获取和使用 UIInterfaceOrientation 项目？

Question

我想在 info.plist 中获取支持的界面方向的 item0。

为了得到这样的东西：

- (UIInterfaceOrientationMask)supportedInterfaceOrientations {

     NSArray *supportedOrientations = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"UISupportedInterfaceOrientations"];

     return supportedOrientations[0]; 

}

但是我当然有一个不兼容类型错误： Incompatible pointer to integer conversion returning 'id' from a function with result type

如何解决？

Answer 1

正如@Mats 在他的评论中提到的，信息字典包含支持方向的字符串值。您需要将字符串值转换为所需的UIInterfaceOrientationMask 类型。您可以使用字符串类别来执行此操作。

NSString+UIDeviceOrientation.h

static NSString *kUIInterfaceOrientationPortrait           = @"UIInterfaceOrientationPortrait";
static NSString *kUIInterfaceOrientationLandscapeLeft      = @"UIInterfaceOrientationLandscapeLeft";
static NSString *kUIInterfaceOrientationLandscapeRight     = @"UIInterfaceOrientationLandscapeRight";
static NSString *kUIInterfaceOrientationPortraitUpsideDown = @"UIInterfaceOrientationPortraitUpsideDown";

@interface NSString (UIDeviceOrientation)

- (UIInterfaceOrientationMask)deviceOrientation;

@end

NSString+UIDeviceOrientation.m

@implementation NSString (UIDeviceOrientation)

- (UIInterfaceOrientationMask)deviceOrientation {
    UIInterfaceOrientationMask mask = UIInterfaceOrientationMaskAll;

    if ([self isEqualToString:kUIInterfaceOrientationPortrait]) {
        mask = UIInterfaceOrientationMaskPortrait;
    }
    else if ([self isEqualToString:kUIInterfaceOrientationLandscapeLeft]) {
        mask = UIInterfaceOrientationMaskLandscapeLeft;
    }
    else if ([self isEqualToString:kUIInterfaceOrientationLandscapeRight]) {
        mask = UIInterfaceOrientationMaskLandscapeRight;
    }
    else if ([self isEqualToString:kUIInterfaceOrientationPortraitUpsideDown]) {
        mask = UIInterfaceOrientationMaskPortraitUpsideDown;
    }

    return mask;
}

Swift 版本

extension String {
private var kUIInterfaceOrientationPortrait: String {
    return "UIInterfaceOrientationPortrait"
}

private var kUIInterfaceOrientationLandscapeLeft: String {
    return "UIInterfaceOrientationLandscapeLeft"
}

private var kUIInterfaceOrientationLandscapeRight: String {
    return "UIInterfaceOrientationLandscapeRight"
}

private var kUIInterfaceOrientationPortraitUpsideDown: String {
    return "UIInterfaceOrientationPortraitUpsideDown"
}

public var deviceOrientation: UIInterfaceOrientationMask {

    switch self {
    case kUIInterfaceOrientationPortrait:
        return .portrait

    case kUIInterfaceOrientationLandscapeLeft:
        return .landscapeLeft

    case kUIInterfaceOrientationLandscapeRight:
        return .landscapeRight

    case kUIInterfaceOrientationPortraitUpsideDown:
        return .portraitUpsideDown

    default:
        return .all
    }
}
}