如何检测iPhone / iPad设备上的总可用/可用磁盘空间？

我正在寻找一种更好的方法来以编程方式检测iPhone / iPad设备上的可用/可用磁盘空间。
目前，我正在使用NSFileManager来检测磁盘空间。以下是对我有用的代码片段：

-(unsigned)getFreeDiskspacePrivate {
NSDictionary *atDict = [[NSFileManager defaultManager] attributesOfFileSystemForPath:@"/" error:NULL];
unsigned freeSpace = [[atDict objectForKey:NSFileSystemFreeSize] unsignedIntValue];
NSLog(@"%s - Free Diskspace: %u bytes - %u MiB", __PRETTY_FUNCTION__, freeSpace, (freeSpace/1024)/1024);

return freeSpace;
}

我对以上代码片段正确吗？还是有更好的方法来了解总的可用/可用磁盘空间。
我必须检测总的可用磁盘空间，因为我们必须防止应用程序在磁盘空间不足的情况下执行同步。

更新：由于在此答案之后已经花费了很多时间，并且添加了新的方法/ API，因此请在下面查看Swift等更新的答案；由于我自己没有使用过它们，因此我不能担保它们。

原始答案：我发现以下解决方案对我有用：

-(uint64_t)getFreeDiskspace {
    uint64_t totalSpace = 0;
    uint64_t totalFreeSpace = 0;
    NSError *error = nil;  
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
    NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths lastObject] error: &error];  

    if (dictionary) {  
        NSNumber *fileSystemSizeInBytes = [dictionary objectForKey: NSFileSystemSize];  
        NSNumber *freeFileSystemSizeInBytes = [dictionary objectForKey:NSFileSystemFreeSize];
        totalSpace = [fileSystemSizeInBytes unsignedLongLongValue];
        totalFreeSpace = [freeFileSystemSizeInBytes unsignedLongLongValue];
        NSLog(@"Memory Capacity of %llu MiB with %llu MiB Free memory available.", ((totalSpace/1024ll)/1024ll), ((totalFreeSpace/1024ll)/1024ll));
    } else {  
        NSLog(@"Error Obtaining System Memory Info: Domain = %@, Code = %ld", [error domain], (long)[error code]);
    }  

    return totalFreeSpace;
}

当设备连接到计算机时，它可以准确返回iTunes显示的大小。

使用unsigned long long修改源代码：

- (uint64_t)freeDiskspace
{
    uint64_t totalSpace = 0;
    uint64_t totalFreeSpace = 0;

    __autoreleasing NSError *error = nil;  
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
    NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths lastObject] error: &error];  

    if (dictionary) {  
        NSNumber *fileSystemSizeInBytes = [dictionary objectForKey: NSFileSystemSize];  
        NSNumber *freeFileSystemSizeInBytes = [dictionary objectForKey:NSFileSystemFreeSize];
        totalSpace = [fileSystemSizeInBytes unsignedLongLongValue];
        totalFreeSpace = [freeFileSystemSizeInBytes unsignedLongLongValue];
        NSLog(@"Memory Capacity of %llu MiB with %llu MiB Free memory available.", ((totalSpace/1024ll)/1024ll), ((totalFreeSpace/1024ll)/1024ll));
    } else {  
        NSLog(@"Error Obtaining System Memory Info: Domain = %@, Code = %d", [error domain], [error code]);  
    }  

    return totalFreeSpace;
}

编辑：似乎有人编辑了此代码以使用'uint64_t'而不是'unsigned long long'。虽然在可预见的将来这应该很好，但它们并不相同。'uint64_t'是64位，并且将始终如此。在10年中，“ unsigned long long”可能是128。这是一个小问题，但是为什么我使用unsignedLongLong。

我已经编写了一个类来使用Swift获取可用/已使用的内存。演示位于：https : //github.com/thanhcuong1990/swift-disk-status
Swift 4已更新。

import UIKit

class DiskStatus {

    //MARK: Formatter MB only
    class func MBFormatter(_ bytes: Int64) -> String {
        let formatter = ByteCountFormatter()
        formatter.allowedUnits = ByteCountFormatter.Units.useMB
        formatter.countStyle = ByteCountFormatter.CountStyle.decimal
        formatter.includesUnit = false
        return formatter.string(fromByteCount: bytes) as String
    }


    //MARK: Get String Value
    class var totalDiskSpace:String {
        get {
            return ByteCountFormatter.string(fromByteCount: totalDiskSpaceInBytes, countStyle: ByteCountFormatter.CountStyle.file)
        }
    }

    class var freeDiskSpace:String {
        get {
            return ByteCountFormatter.string(fromByteCount: freeDiskSpaceInBytes, countStyle: ByteCountFormatter.CountStyle.file)
        }
    }

    class var usedDiskSpace:String {
        get {
            return ByteCountFormatter.string(fromByteCount: usedDiskSpaceInBytes, countStyle: ByteCountFormatter.CountStyle.file)
        }
    }


    //MARK: Get raw value
    class var totalDiskSpaceInBytes:Int64 {
        get {
            do {
                let systemAttributes = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory() as String)
                let space = (systemAttributes[FileAttributeKey.systemSize] as? NSNumber)?.int64Value
                return space!
            } catch {
                return 0
            }
        }
    }

    class var freeDiskSpaceInBytes:Int64 {
        get {
            do {
                let systemAttributes = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory() as String)
                let freeSpace = (systemAttributes[FileAttributeKey.systemFreeSize] as? NSNumber)?.int64Value
                return freeSpace!
            } catch {
                return 0
            }
        }
    }

    class var usedDiskSpaceInBytes:Int64 {
        get {
            let usedSpace = totalDiskSpaceInBytes - freeDiskSpaceInBytes
            return usedSpace
        }
    }

}

演示版

如果您需要格式化的字符串和大小，可以在GitHub上查看漂亮的库：

#define MB (1024*1024)
#define GB (MB*1024)

@implementation ALDisk

#pragma mark - Formatter

+ (NSString *)memoryFormatter:(long long)diskSpace {
    NSString *formatted;
    double bytes = 1.0 * diskSpace;
    double megabytes = bytes / MB;
    double gigabytes = bytes / GB;
    if (gigabytes >= 1.0)
        formatted = [NSString stringWithFormat:@"%.2f GB", gigabytes];
    else if (megabytes >= 1.0)
        formatted = [NSString stringWithFormat:@"%.2f MB", megabytes];
    else
        formatted = [NSString stringWithFormat:@"%.2f bytes", bytes];

    return formatted;
}

#pragma mark - Methods

+ (NSString *)totalDiskSpace {
    long long space = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemSize] longLongValue];
    return [self memoryFormatter:space];
}

+ (NSString *)freeDiskSpace {
    long long freeSpace = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemFreeSize] longLongValue];
    return [self memoryFormatter:freeSpace];
}

+ (NSString *)usedDiskSpace {
    return [self memoryFormatter:[self usedDiskSpaceInBytes]];
}

+ (CGFloat)totalDiskSpaceInBytes {
    long long space = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemSize] longLongValue];
    return space;
}

+ (CGFloat)freeDiskSpaceInBytes {
    long long freeSpace = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil] objectForKey:NSFileSystemFreeSize] longLongValue];
    return freeSpace;
}

+ (CGFloat)usedDiskSpaceInBytes {
    long long usedSpace = [self totalDiskSpaceInBytes] - [self freeDiskSpaceInBytes];
    return usedSpace;
}

不要使用“无符号”，只有32位会溢出4GB，这比典型的iPad / iPhone可用空间要少。使用unsigned long long（或uint64_t），并也使用unsignedLongLongValue从NSNumber作为64位int检索值。

如果您希望使用Swift获得剩余的可用空间，则略有不同。您需要使用attributesOfFileSystemForPath（）而不是attributesOfItemAtPath（）：

func deviceRemainingFreeSpaceInBytes() -> Int64? {
    let documentDirectoryPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
    var attributes: [String: AnyObject]
    do {
        attributes = try NSFileManager.defaultManager().attributesOfFileSystemForPath(documentDirectoryPath.last! as String)
        let freeSize = attributes[NSFileSystemFreeSize] as? NSNumber
        if (freeSize != nil) {
            return freeSize?.longLongValue
        } else {
            return nil
        }
    } catch {
        return nil
    }
}

编辑：为Swift 1.0更新。
编辑2：为安全起见，使用Martin R的答案进行了更新。
编辑3：已为Swift 2.0更新（由dgellow）

这是我的答案，为什么会更好。

答案（快速）：

func remainingDiskSpaceOnThisDevice() -> String {
    var remainingSpace = NSLocalizedString("Unknown", comment: "The remaining free disk space on this device is unknown.")
    if let attributes = try? FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory()),
        let freeSpaceSize = attributes[FileAttributeKey.systemFreeSize] as? Int64 {
        remainingSpace = ByteCountFormatter.string(fromByteCount: freeSpaceSize, countStyle: .file)
    }
    return remainingSpace
}

答案（目标C）：

- (NSString *)calculateRemainingDiskSpaceOnThisDevice
{
    NSString *remainingSpace = NSLocalizedString(@"Unknown", @"The remaining free disk space on this device is unknown.");
    NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil];
    if (dictionary) {
        long long freeSpaceSize = [[dictionary objectForKey:NSFileSystemFreeSize] longLongValue];
        remainingSpace = [NSByteCountFormatter stringFromByteCount:freeSpaceSize countStyle:NSByteCountFormatterCountStyleFile];
    }
    return remainingSpace;
}

为什么更好：

• 利用Cocoa的内置库NSByteCountFormatter，这意味着从字节到千兆字节都不会进行疯狂的手动计算。苹果为您做到这一点！
• 轻松翻译：NSByteCountFormatter为您做到这一点。例如，当设备的语言设置为英语时，该字符串将读取248.8 MB，但在设置为法语等其他语言时，该字符串将显示248,8Mo。
• 发生错误时将提供默认值。

重要的说明（至少对我来说）。如果我将iPod连接到Mac，这就是iTunes App显示的信息。

当我使用上面的代码时：

long long freeSpace = [[[[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil]
                            objectForKey:NSFileSystemFreeSize] longLongValue];

NSString *free1 = [NSByteCountFormatter stringFromByteCount:freeSpace countStyle:NSByteCountFormatterCountStyleFile];

[label1 setText:free1];

NSString *free2 = [NSByteCountFormatter stringFromByteCount:freeSpace countStyle:NSByteCountFormatterCountStyleBinary];

[label2 setText:free2];

countStyle NSByteCountFormatterCountStyleFile向我展示：17,41 GB

countStyle NSByteCountFormatterCountStyleBinary向我展示：16,22 GB

16,22 GB（NSByteCountFormatterCountStyleBinary）是EXACTLY是iTunes应用程序告诉我，当我在我的iPod连接到我的Mac数量。

使用新的准确API更新，以获取iOS11中可用磁盘上的可用大小。这是新API资源密钥的描述：

#if os(OSX) || os(iOS)
/// Total available capacity in bytes for "Important" resources, including space expected to be cleared by purging non-essential and cached resources. "Important" means something that the user or application clearly expects to be present on the local system, but is ultimately replaceable. This would include items that the user has explicitly requested via the UI, and resources that an application requires in order to provide functionality.
/// Examples: A video that the user has explicitly requested to watch but has not yet finished watching or an audio file that the user has requested to download.
/// This value should not be used in determining if there is room for an irreplaceable resource. In the case of irreplaceable resources, always attempt to save the resource regardless of available capacity and handle failure as gracefully as possible.
@available(OSX 10.13, iOS 11.0, *) @available(tvOS, unavailable) @available(watchOS, unavailable)
public var volumeAvailableCapacityFor Usage: Int64? { return _get(.volumeAvailableCapacityForImportantUsageKey) }
#endif

我交叉比较了键“ FileAttributeKey.systemFreeSize ”和键“ URLResourceKey.volumeAvailableCapacityForImportantUsageKey ”的结果，发现从“ volumeAvailableCapacityForImportantUsageKey ” 返回的结果与UI上显示的可用存储完全匹配。 这是快速的实现：

class var freeDiskSpaceInBytesImportant:Int64 {
    get {
        do {
            return try URL(fileURLWithPath: NSHomeDirectory() as String).resourceValues(forKeys: [URLResourceKey.volumeAvailableCapacityForImportantUsageKey]).volumeAvailableCapacityForImportantUsage!
        } catch {
            return 0
        }
    }
}

你可以找到与使用另一种解决方案斯威夫特4和extension它给你一个不错的选择。

这是UIDevice扩展名。

extension UIDevice {

    func totalDiskSpaceInBytes() -> Int64 {
        do {
            guard let totalDiskSpaceInBytes = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory())[FileAttributeKey.systemSize] as? Int64 else {
                return 0
            }
            return totalDiskSpaceInBytes
        } catch {
            return 0
        }
    }

    func freeDiskSpaceInBytes() -> Int64 {
        do {
            guard let totalDiskSpaceInBytes = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory())[FileAttributeKey.systemFreeSize] as? Int64 else {
                return 0 
            }
            return totalDiskSpaceInBytes
        } catch {
            return 0
        }
    }

    func usedDiskSpaceInBytes() -> Int64 {
        return totalDiskSpaceInBytes() - freeDiskSpaceInBytes()
    }

    func totalDiskSpace() -> String {
        let diskSpaceInBytes = totalDiskSpaceInBytes()
        if diskSpaceInBytes > 0 {
            return ByteCountFormatter.string(fromByteCount: diskSpaceInBytes, countStyle: ByteCountFormatter.CountStyle.binary)
        }
        return "The total disk space on this device is unknown"
    }

    func freeDiskSpace() -> String {
        let freeSpaceInBytes = freeDiskSpaceInBytes()
        if freeSpaceInBytes > 0 {
            return ByteCountFormatter.string(fromByteCount: freeSpaceInBytes, countStyle: ByteCountFormatter.CountStyle.binary)
        }
        return "The free disk space on this device is unknown"
    }

    func usedDiskSpace() -> String {
        let usedSpaceInBytes = totalDiskSpaceInBytes() - freeDiskSpaceInBytes()
        if usedSpaceInBytes > 0 {
            return ByteCountFormatter.string(fromByteCount: usedSpaceInBytes, countStyle: ByteCountFormatter.CountStyle.binary)
        }
        return "The used disk space on this device is unknown"
    }

}

和示例用法：

UIDevice.current.totalDiskSpaceInBytes()
UIDevice.current.totalDiskSpace()
UIDevice.current.freeDiskSpaceInBytes()
UIDevice.current.freeDiskSpace()
UIDevice.current.usedDiskSpaceInBytes()
UIDevice.current.usedDiskSpace()

对于iOS> = 6.0，可以使用new NSByteCountFormatter。此代码获取保留为格式化字符串的可用字节数。

NSError *error = nil;
NSArray * const paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSDictionary * const pathAttributes = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths firstObject] error:&error];
NSAssert(pathAttributes, @"");
NSNumber * const fileSystemSizeInBytes = [pathAttributes objectForKey: NSFileSystemFreeSize];
const long long numberOfBytesRemaining = [fileSystemSizeInBytes longLongValue];
NSByteCountFormatter *byteCountFormatter = [[NSByteCountFormatter alloc] init];
NSString *formattedNmberOfBytesRemaining = [byteCountFormatter stringFromByteCount:numberOfBytesRemaining];

以下代码是ChrisJF先前提供的答案的Swift 3.0版本实现：

func freeSpaceInBytes() -> NSString {

    var remainingSpace = NSLocalizedString("Unknown", comment: "The remaining free disk space on this device is unknown.")

    do {
        let dictionary =  try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory())
        let freeSpaceSize = ((dictionary[FileAttributeKey.systemFreeSize] as AnyObject).longLongValue)!
        remainingSpace = ByteCountFormatter.string(fromByteCount: freeSpaceSize, countStyle: ByteCountFormatter.CountStyle.file)
    }
    catch let error {
        NSLog(error.localizedDescription)
    }

    return remainingSpace as NSString

}

用于Swift作为UIDevice扩展

extension UIDevice {
    func freeDiskspace() -> NSString {
        let failedResult: String = "Error Obtaining System Memory"
        guard let path = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true).last else {
            return failedResult
        }
        do {
            let dictionary = try NSFileManager.defaultManager().attributesOfFileSystemForPath(path)
            if let fileSystemSizeInBytes = dictionary[NSFileSystemSize] as? UInt,
                let freeFileSystemSizeInBytes =     dictionary[NSFileSystemFreeSize] as? UInt {
                    return "Memory \(freeFileSystemSizeInBytes/1024/1024) of \(fileSystemSizeInBytes/1024/1024) Mb available."
            } else {
                    return failedResult
            }
        } catch {
            return failedResult
        }
    }
}

如何使用：

print("\(UIDevice.currentDevice().freeDiskspace())")

输出将是：

Memory 9656 of 207694 Mb available.

我知道这篇文章有点老了，但是我认为这个答案可以帮助某人。如果您想知道设备上的已用/可用/总磁盘空间，可以使用Luminous。它是用Swift编写的。您只需致电：

Luminous.System.Disk.freeSpace()
Luminous.System.Disk.usedSpace()

要么

Luminous.System.Disk.freeSpaceInBytes()
Luminous.System.Disk.usedSpaceInBytes()

上面代码的Swift实现：

import UIKit

class DiskInformation: NSObject {

    var totalSpaceInBytes: CLongLong = 0; // total disk space
    var totalFreeSpaceInBytes: CLongLong = 0; //total free space in bytes

    func getTotalDiskSpace() -> String { //get total disk space
        do{
        let space: CLongLong = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory())[FileAttributeKey.systemSize] as! CLongLong; //Check for home dirctory and get total system size
            totalSpaceInBytes = space; // set as total space
            return memoryFormatter(space: space); // send the total bytes to formatter method and return the output

        }catch let error{ // Catch error that may be thrown by FileManager
            print("Error is ", error);
        }
        return "Error while getting memory size";
    }

    func getTotalFreeSpace() -> String{ //Get total free space
        do{
            let space: CLongLong = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory())[FileAttributeKey.systemFreeSize] as! CLongLong;
            totalFreeSpaceInBytes = space;
            return memoryFormatter(space: space);

        }catch let error{
            print("Error is ", error);
        }
        return "Error while getting memory size";
    }

    func getTotalUsedSpace() -> String{ //Get total disk usage from above variable
        return memoryFormatter(space: (totalSpaceInBytes - totalFreeSpaceInBytes));
    }

    func memoryFormatter(space : CLongLong) -> String{ //Format the usage to return value with 2 digits after decimal
        var formattedString: String;

        let totalBytes: Double = 1.0 * Double(space);
        let totalMb: Double = totalBytes / (1024 * 1024);
        let totalGb: Double = totalMb / 1024;
        if (totalGb > 1.0){
            formattedString = String(format: "%.2f", totalGb);
        }else if(totalMb >= 1.0){
            formattedString = String(format: "%.2f", totalMb);
        }else{
            formattedString = String(format: "%.2f", totalBytes);
        }
        return formattedString;
    }


}

从其他任何类调用它。

func getDiskInfo(){
        let diskInfo = DiskInformation();
        print("Total disk space is", diskInfo.getTotalDiskSpace(),"Gb");
        print("Total free space is", diskInfo.getTotalFreeSpace(),"Gb");
        print("Total used space is", diskInfo.getTotalUsedSpace(),"Gb");
    }

测试返回值时，它与其他应用程序显示的相同。至少在我的iPhone 6S +中。这只是上面显示的答案的快速实现。对我来说，被接受的答案是行不通的。

Swift 2.1版本中的ChrisJF答案：

func freeSpaceInBytes() -> NSString{

    var remainingSpace = NSLocalizedString("Unknown", comment: "The remaining free disk space on this device is unknown.")

    do {

        let dictionary =  try NSFileManager.defaultManager().attributesOfFileSystemForPath(NSHomeDirectory())
        freeSpaceSize = (dictionary[NSFileSystemFreeSize]?.longLongValue)!
        remainingSpace = NSByteCountFormatter.stringFromByteCount(freeSpaceSize, countStyle: NSByteCountFormatterCountStyle.File)

    }
    catch let error as NSError {

        error.description
        NSLog(error.description)

    }

    return remainingSpace

}

如果您想节省时间，请使用以下CocoaPod库。我没有使用它，但似乎应该可以使用。

https://cocoapods.org/pods/SystemServices

Swift 5扩展，可FileManager进行适当的错误处理，并且不会自动进行字符串转换（可以根据需要将字节数转换为字符串）。也遵循FileManager的命名。

extension FileManager {
    func systemFreeSizeBytes() -> Result<Int64, Error> {
        do {
            let attrs = try attributesOfFileSystem(forPath: NSHomeDirectory())
            guard let freeSize = attrs[.systemFreeSize] as? Int64 else {
                return .failure(NSError(domain: "", code: 0, userInfo: [NSLocalizedDescriptionKey : "Can't retrieve system free size"]))
            }
            return .success(freeSize)
        } catch {
            return .failure(error)
        }
    }

    func systemSizeBytes() -> Result<Int64, Error> {
         do {
             let attrs = try attributesOfFileSystem(forPath: NSHomeDirectory())
             guard let size = attrs[.systemSize] as? Int64 else {
                 return .failure(NSError(domain: "", code: 0, userInfo: [NSLocalizedDescriptionKey : "Can't retrieve system size"]))
             }
             return .success(size)
         } catch {
             return .failure(error)
         }
     }
}

用法示例：

let freeSizeResult = FileManager.default.systemFreeSizeBytes()
switch freeSizeResult {
case .failure(let error):
    print(error)
case .success(let freeSize):
    let freeSizeString = ByteCountFormatter.string(fromByteCount: freeSize, countStyle: .file)
    print("free size: \(freeSizeString)")
}