iOS 4.1 中的 NSCFNumber 类是什么？
在iOS 4.1上成功从iPhone相机获取图片后，您可以使用该密钥
@"UIImagePickerControllerMediaMetadata"
返回有关图片的信息。该字典中的键之一是
@"Orientation"
根据我的实验，肖像和颠倒分别是 6 和 8，风景是 1 和 3。看看这段代码：
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSDictionary *metaData = [info objectForKey:@"UIImagePickerControllerMediaMetadata"];
id orientation = [metaData objectForKey:@"Orientation"];
NSLog(@"Class: %@",[orientation class]);
NSLog 说“Class：NSCFNumber”
我需要比较这个对象的值以确定如何进行。横向是 1 或 3，纵向是 6 或 8。我不确定要输入什么方向或在其上调用什么。 NSNumber 和 NSInteger 总是告诉我我正在从指针生成整数而不进行强制转换。
感谢您抽出时间！
After successfully acquiring a picture from the iPhone camera on iOS 4.1, you can use the key
@"UIImagePickerControllerMediaMetadata"
to return information about the picture. One of the keys in that dictionary is
@"Orientation"
From my experimentation, Portrait and Upside down are 6 and 8 respectively, and the landscapes are 1 and 3. Look at this code:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NSDictionary *metaData = [info objectForKey:@"UIImagePickerControllerMediaMetadata"];
id orientation = [metaData objectForKey:@"Orientation"];
NSLog(@"Class: %@",[orientation class]);
The NSLog says "Class: NSCFNumber"
I need to compare this object's value to determine how to proceed. Landscape is 1 or 3, portrait is 6 or 8. I'm not sure what to type orientation as or what to call on it. NSNumber and NSInteger always tells me I'm making integers from pointers without casts.
Thanks for your time!
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这告诉您方向是
NSNumber的一个实例。从技术上讲，NSCFNumber是NSNumber的私有子类，但这是您不必担心的实现细节。要获取整数值，您可以调用This is telling you that orientation is a instance of
NSNumber. Technically,NSCFNumberis a private subclass ofNSNumber, but that is an implementation detail which you don't have to worry about. To get the integer value you would callNSNumber是一个类簇。NSCFNumber是该集群中类的具体“私有”实现。只需像使用NSNumber对象一样使用返回值即可。NSNumberis a class cluster.NSCFNumberis a concrete, "private" implementation of a class in that cluster. Just use the returned value like you would anNSNumberobject.如今（2022）该方法已更改名称，您需要将其转换为 NSNumber 才能使用它，如下所示：
如果您想在 OutputConsole 上打印它，则需要使用 %d 而不是 %@，例如:
Nowadays (2022) the method has changed the name, and you needed to cast it to NSNumber before you can use it, like this:
And if you want to print it on OutputConsole, you need to use %d instead of %@, e.g.: