blocks|key|926437|text|不要使用'unsigned'，它只有32位，会溢出超过4+4GB，这比典型的iPad/iPhone可用空间要少。使用unsigned+long+long+(或uint64_t)，并使用unsignedLongLongValue从NSNumber中检索64位整数形式的值。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|926438|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Don't use 'unsigned', it is only 32 bits which will overflow past 4GB, which is less than the typical iPad/iPhone free space. Use unsigned long long (or uint64_t), and retrieve the value out of the NSNumber as a 64-bit int too using unsignedLongLongValue.

blocks|key|710319|text|使用unsigned+long+long修改源代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|710320|-+(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+%25llu+MiB+with+%25llu+MiB+Free+memory+available.",+((totalSpace/1024ll)/1024ll),+((totalFreeSpace/1024ll)/1024ll));
++++}+else+{++
++++++++NSLog(@"Error+Obtaining+System+Memory+Info:+Domain+=+%25@,+Code+=+%25d",+[error+domain],+[error+code]);++
++++}++

++++return+totalFreeSpace;
}|code-block|syntax|javascript|710321|编辑:似乎有人将此代码编辑为使用“uint64_t”而不是“unsigned+long+long”。虽然在可预见的未来，这应该是很好的，但它们是不一样的。'uint64_t‘是64位的，并且永远是64位的。10年后，“无符号long+long”可能是128。这是一个小问题，但为什么我使用unsignedLongLong。|710322|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Revised source using unsigned long long:

<pre><code>- (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: &amp;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;
}
</code></pre>

EDIT: it seems someone edited this code to use 'uint64_t' instead of 'unsigned long long'. While in the foreseeable future this should be just fine, they are not the same. 'uint64_t' is 64 bits and will always be that. In 10 years 'unsigned long long' might be 128. its a small point but why I used unsignedLongLong.

blocks|key|710399|text|如果您需要带大小的格式化字符串，可以查看nice+library+on+GitHub|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|710400|#define+MB+(1024*1024)
#define+GB+(MB*1024)

@implementation+ALDisk

#pragma+mark+-+Formatter

%2B+(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:@"%25.2f+GB",+gigabytes];
++++else+if+(megabytes+>=+1.0)
++++++++formatted+=+[NSString+stringWithFormat:@"%25.2f+MB",+megabytes];
++++else
++++++++formatted+=+[NSString+stringWithFormat:@"%25.2f+bytes",+bytes];

++++return+formatted;
}

#pragma+mark+-+Methods

%2B+(NSString+*)totalDiskSpace+{
++++long+long+space+=+[[[[NSFileManager+defaultManager]+attributesOfFileSystemForPath:NSHomeDirectory()+error:nil]+objectForKey:NSFileSystemSize]+longLongValue];
++++return+[self+memoryFormatter:space];
}

%2B+(NSString+*)freeDiskSpace+{
++++long+long+freeSpace+=+[[[[NSFileManager+defaultManager]+attributesOfFileSystemForPath:NSHomeDirectory()+error:nil]+objectForKey:NSFileSystemFreeSize]+longLongValue];
++++return+[self+memoryFormatter:freeSpace];
}

%2B+(NSString+*)usedDiskSpace+{
++++return+[self+memoryFormatter:[self+usedDiskSpaceInBytes]];
}

%2B+(CGFloat)totalDiskSpaceInBytes+{
++++long+long+space+=+[[[[NSFileManager+defaultManager]+attributesOfFileSystemForPath:NSHomeDirectory()+error:nil]+objectForKey:NSFileSystemSize]+longLongValue];
++++return+space;
}

%2B+(CGFloat)freeDiskSpaceInBytes+{
++++long+long+freeSpace+=+[[[[NSFileManager+defaultManager]+attributesOfFileSystemForPath:NSHomeDirectory()+error:nil]+objectForKey:NSFileSystemFreeSize]+longLongValue];
++++return+freeSpace;
}

%2B+(CGFloat)usedDiskSpaceInBytes+{
++++long+long+usedSpace+=+[self+totalDiskSpaceInBytes]+-+[self+freeDiskSpaceInBytes];
++++return+usedSpace;
}|code-block|syntax|javascript|710401|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/andrealufino/ALSystemUtilities/blob/develop/ALSystemUtilities/ALSystemUtilities/ALDisk/ALDisk.m^0|K|M|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

If you need formatted string with size you can take a look at <a href="https://github.com/andrealufino/ALSystemUtilities/blob/develop/ALSystemUtilities/ALSystemUtilities/ALDisk/ALDisk.m">nice library on GitHub</a>:

<pre><code>#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 &gt;= 1.0)
 formatted = [NSString stringWithFormat:@"%.2f GB", gigabytes];
 else if (megabytes &gt;= 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;
}
</code></pre>

blocks|key|926681|text|对于iOS+>=+6.0，您可以使用新的NSByteCountFormatter。此代码以格式化字符串的形式获取剩余的空闲字节数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|926682|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];|code-block|syntax|javascript|926683|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/library/ios/documentation/Foundation/Reference/NSByteCountFormatter_Class/Reference/Reference.html^0|K|K|K|K|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@$9|V|A|W|1|X]]|E|$]]|$1|F|3|G|5|H|7|Y|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

For iOS >= 6.0 you can use the new <a href="https://developer.apple.com/library/ios/documentation/Foundation/Reference/NSByteCountFormatter_Class/Reference/Reference.html" rel="nofollow"><code>NSByteCountFormatter</code></a>. This code gets the number of free bytes remaining as a formatted string. 

<pre><code>NSError *error = nil;
NSArray * const paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSDictionary * const pathAttributes = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths firstObject] error:&amp;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];
</code></pre>

blocks|key|710595|text|如果您希望使用Swift获取剩余可用空间，则略有不同。您需要使用attributesOfFileSystemForPath()而不是attributesOfItemAtPath()：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|710596|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
++++}
}|code-block|syntax|javascript|710597|编辑:针对Swift+1.0更新|710598|编辑2:为安全起见，更新，using+Martin+R's+answer。|offset|length|710599|编辑3:针对Swift+2.0进行了更新(由dgellow提供)|710600|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/26198073/query-available-ios-device-memory-with-swift|1|https://stackoverflow.com/users/709884/dgellow^0|0|0|0|D|N|0|0|M|7|1|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|11|8|@]|9|@$K|12|L|13|1|14]]|A|$]]|$1|M|3|N|5|6|7|15|8|@]|9|@$K|16|L|17|1|18]]|A|$]]|$1|O|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]|W|$5|R|S|T|A|$U|X]]]]

If your looking to get the the remaining free space using Swift it is slightly different. You need to use attributesOfFileSystemForPath() instead of attributesOfItemAtPath():

<pre><code>func deviceRemainingFreeSpaceInBytes() -&gt; 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
 }
}
</code></pre>

Edit: Updated for Swift 1.0 
Edit 2: Updated for safety, <a href="https://stackoverflow.com/questions/26198073/query-available-ios-device-memory-with-swift">using Martin R's answer</a>. 
Edit 3: Updated for Swift 2.0 (by <a href="https://stackoverflow.com/users/709884/dgellow">dgellow</a>)

blocks|key|710695|text|我已经编写了一个使用Swift获取可用/已用内存的类。演示地址：https://github.com/thanhcuong1990/swift-disk-status|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|710696|Swift+4已更新。|710697|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
++++++++}
++++}

}|code-block|syntax|javascript|710698|演示|710699|​|710700|📷|atomic|710701|710702|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/thanhcuong1990/swift-disk-status|1|IMAGE|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/e3e3e2dce219356c3edc355d67354c67.png|imageAlt^0|W|1F|0|0|0|0|0|0|0|1|1|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@$A|17|B|18|1|19]]|C|$]]|$1|D|3|E|5|6|7|1A|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|1B|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|1C|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|1D|8|@]|9|@]|C|$]]|$1|O|3|P|5|Q|7|1E|8|@]|9|@$A|1F|B|1G|1|1H]]|C|$]]|$1|R|3|N|5|6|7|1I|8|@]|9|@]|C|$]]|$1|S|3|-4|5|6|7|1J|8|@]|9|@]|C|$]]]|T|$U|$5|V|W|X|C|$Y|Z]]|10|$5|11|W|12|C|$13|14|15|-4]]]]

I have written a class to get available/used memory using Swift. 
Demo at: <a href="https://github.com/thanhcuong1990/swift-disk-status" rel="noreferrer">https://github.com/thanhcuong1990/swift-disk-status</a> 
Swift 4 updated.

<pre><code>import UIKit

class DiskStatus {

 //MARK: Formatter MB only
 class func MBFormatter(_ bytes: Int64) -&gt; 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
 }
 }

}
</code></pre>

Demo

<img src="https://i.stack.imgur.com/C7gpW.png" alt="get disk space status with Swift">

blocks|key|926989|text|我知道这篇文章有点老了，但我认为这个答案可以帮助一些人。如果您想知道设备上已用/可用/总的磁盘空间，可以使用Luminous。它是用Swift写的。您只需调用：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|926990|Luminous.System.Disk.freeSpace()
Luminous.System.Disk.usedSpace()|code-block|syntax|javascript|926991|或|926992|Luminous.System.Disk.freeSpaceInBytes()
Luminous.System.Disk.usedSpaceInBytes()|926993|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/andrealufino/Luminous^0|1I|8|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

I know this post is a bit old, but I think this answer can help someone. If you want to know the used/free/total disk space on the device you can use <a href="https://github.com/andrealufino/Luminous" rel="nofollow">Luminous</a>. It's written in Swift. You have only to call :

<pre><code>Luminous.System.Disk.freeSpace()
Luminous.System.Disk.usedSpace()
</code></pre>

or

<pre><code>Luminous.System.Disk.freeSpaceInBytes()
Luminous.System.Disk.usedSpaceInBytes()
</code></pre>

blocks|key|710867|text|以下代码是之前由ChrisJF提供的答案的Swift+3.0版本实现：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|710868|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

}|code-block|syntax|javascript|710869|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Following code is Swift 3.0 version implementation of the answer previously provided by ChrisJF:

<pre><code>func freeSpaceInBytes() -&gt; 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

}
</code></pre>

blocks|key|927151|text|上述代码的快速实现：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|927152|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:+"%25.2f",+totalGb);
++++++++}else+if(totalMb+>=+1.0){
++++++++++++formattedString+=+String(format:+"%25.2f",+totalMb);
++++++++}else{
++++++++++++formattedString+=+String(format:+"%25.2f",+totalBytes);
++++++++}
++++++++return+formattedString;
++++}


}|code-block|syntax|javascript|927153|从任何其他类调用它。|927154|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");
++++}|927155|测试返回值时，与其他应用显示相同。至少在我的iPhone+6S%2B里。这只是上面显示的答案的快速实现。对我来说，被接受的答案并不管用。|927156|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Swift implementation of above code:- 

<pre><code>import UIKit

class DiskInformation: NSObject {

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

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

 func memoryFormatter(space : CLongLong) -&gt; 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 &gt; 1.0){
 formattedString = String(format: "%.2f", totalGb);
 }else if(totalMb &gt;= 1.0){
 formattedString = String(format: "%.2f", totalMb);
 }else{
 formattedString = String(format: "%.2f", totalBytes);
 }
 return formattedString;
 }


}
</code></pre>

Call it from any other class.

<pre><code>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");
 }
</code></pre>

While testing the returned value, it's same as shown by other apps. At least in my iPhone 6S+. It's just the swift implementation of the above shown answer. And for me the accepted answer didn't work.

blocks|key|711048|text|如果你想节省时间，可以使用下面的CocoaPod库。我没有使用它，但看起来它应该可以工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|711049|https://cocoapods.org/pods/SystemServices|offset|length|711050|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|15|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

If you want to save time, use the following CocoaPod Library. I didn't used it but seems like it should work.

<a href="https://cocoapods.org/pods/SystemServices" rel="nofollow noreferrer">https://cocoapods.org/pods/SystemServices</a>

blocks|key|711145|text|这是针对FileManager的Swift+5扩展，它具有正确的错误处理，并且没有自动字符串转换(根据您的喜好将字节数转换为字符串)。也遵循FileManager的命名。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|711146|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)
+++++++++}
+++++}
}|code-block|syntax|javascript|711147|示例用法：|711148|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)")
}|711149|entityMap^0|4|B|1Y|B|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

Here is Swift 5 extension for <code>FileManager</code> with proper error handling and no automatic string conversions (convert byte count to string as you prefer). Also follows <code>FileManager</code>'s naming.
<pre><code>extension FileManager {
 func systemFreeSizeBytes() -&gt; Result&lt;Int64, Error&gt; {
 do {
 let attrs = try attributesOfFileSystem(forPath: NSHomeDirectory())
 guard let freeSize = attrs[.systemFreeSize] as? Int64 else {
 return .failure(NSError(domain: &quot;&quot;, code: 0, userInfo: [NSLocalizedDescriptionKey : &quot;Can't retrieve system free size&quot;]))
 }
 return .success(freeSize)
 } catch {
 return .failure(error)
 }
 }

 func systemSizeBytes() -&gt; Result&lt;Int64, Error&gt; {
 do {
 let attrs = try attributesOfFileSystem(forPath: NSHomeDirectory())
 guard let size = attrs[.systemSize] as? Int64 else {
 return .failure(NSError(domain: &quot;&quot;, code: 0, userInfo: [NSLocalizedDescriptionKey : &quot;Can't retrieve system size&quot;]))
 }
 return .success(size)
 } catch {
 return .failure(error)
 }
 }
}
</code></pre>
Example usage:
<pre><code>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(&quot;free size: \(freeSizeString)&quot;)
}
</code></pre>

I'm looking for a better way to detect available/free disk space on the iPhone/iPad device programmatically. 
Currently I'm using the NSFileManager to detect the disk space. Following is the snippet of the code which does the job for me: 

<pre><code>-(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;
}
</code></pre>

 
Am I correct with the above snippet? or is there any better way to know total available/free disk space. 
I've to detect total free disk space, since we've to prevent our application to perform sync in the low disk space scenario.

How to detect total available/free disk space on the iPhone/iPad device?

Swift

我正在寻找一种更好的方法来检测iPhone/iPad设备上的可用/空闲磁盘空间。目前，我正在使用NSFileManager来检测磁盘空间。下面是为我完成这项工作的代码片段：-(unsigned)getFreeDiskspacePrivate {NSDictionary *atDict = [[NSFileManager...

问如何检测iPhone/iPad设备上的总可用/空闲磁盘空间？
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