查找文件大小

发布于 2024-11-02 16:57:23 字数 549 浏览 1 评论 0原文

在我的 iPhone 应用程序中，我使用以下代码来查找文件的大小。即使文件存在，我看到的大小为零。

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *URL = [documentsDirectory stringByAppendingPathComponent:@"XML/Extras/Approval.xml"];

NSLog(@"URL:%@", URL);
NSError *attributesError = nil;
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:URL error:&attributesError];

int fileSize = [fileAttributes fileSize];

原文

In my iPhone app I am using the following code to find a file's size. Even though the file exists, I am seeing zero for the size.

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *URL = [documentsDirectory stringByAppendingPathComponent:@"XML/Extras/Approval.xml"];

NSLog(@"URL:%@", URL);
NSError *attributesError = nil;
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:URL error:&attributesError];

int fileSize = [fileAttributes fileSize];

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骄兵必败 2024-11-09 16:57:23

试试这个；

NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:URL error:&attributesError];

NSNumber *fileSizeNumber = [fileAttributes objectForKey:NSFileSize];
long long fileSize = [fileSizeNumber longLongValue];

请注意，fileSize 不一定适合整数（尤其是带符号的整数），但对于 iOS，您当然可以将其降至 long，因为实际上您永远不会超过该值。该示例使用 long long，因为在我的代码中我必须与具有更大可用存储空间的系统兼容。

Try this;

NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:URL error:&attributesError];

NSNumber *fileSizeNumber = [fileAttributes objectForKey:NSFileSize];
long long fileSize = [fileSizeNumber longLongValue];

Note that the fileSize won't necessarily fit in an integer (especially a signed one) although you could certainly drop to a long for iOS as you'll never exceed that in reality. The example uses long long as in my code I have to be compatible with systems with much larger storage available.

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迷荒 2024-11-09 16:57:23

Swift 中的一个班轮：

let fileSize = try! NSFileManager.defaultManager().attributesOfItemAtPath(fileURL.path!)[NSFileSize]!.longLongValue

One liner in Swift:

let fileSize = try! NSFileManager.defaultManager().attributesOfItemAtPath(fileURL.path!)[NSFileSize]!.longLongValue

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无法言说的痛 2024-11-09 16:57:23

如果您有 URL（NSURL，而不是 String），则无需使用 FileManager 即可获取文件大小:

 let attributes = try? myURL.resourceValues(forKeys: Set([.fileSizeKey]))
 let fileSize = attributes?.fileSize // Int?

If you have a URL (NSURL, not a String), you can get the file size without a FileManager:

 let attributes = try? myURL.resourceValues(forKeys: Set([.fileSizeKey]))
 let fileSize = attributes?.fileSize // Int?

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自由如风 2024-11-09 16:57:23

斯威夫特 4.x

do {
    let fileSize = try (FileManager.default.attributesOfItem(atPath: filePath) as NSDictionary).fileSize()
            print(fileSize)
    } catch let error {
            print(error)
    }

Swift 4.x

do {
    let fileSize = try (FileManager.default.attributesOfItem(atPath: filePath) as NSDictionary).fileSize()
            print(fileSize)
    } catch let error {
            print(error)
    }

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岁月流歌 2024-11-09 16:57:23

获取文件大小（以 MB 为单位）
尝试此代码 swift

func getSizeOfFile(withPath path:String) -> UInt64?
{
    var totalSpace : UInt64?

    var dict : [FileAttributeKey : Any]?

    do {
        dict = try FileManager.default.attributesOfItem(atPath: path)
    } catch let error as NSError {
         print(error.localizedDescription)
    }

    if dict != nil {
        let fileSystemSizeInBytes = dict![FileAttributeKey.systemSize] as! NSNumber

        totalSpace = fileSystemSizeInBytes.uint64Value
        return (totalSpace!/1024)/1024
    }
    return nil
}

Get the file size in MB
Try This code for swift

func getSizeOfFile(withPath path:String) -> UInt64?
{
    var totalSpace : UInt64?

    var dict : [FileAttributeKey : Any]?

    do {
        dict = try FileManager.default.attributesOfItem(atPath: path)
    } catch let error as NSError {
         print(error.localizedDescription)
    }

    if dict != nil {
        let fileSystemSizeInBytes = dict![FileAttributeKey.systemSize] as! NSNumber

        totalSpace = fileSystemSizeInBytes.uint64Value
        return (totalSpace!/1024)/1024
    }
    return nil
}

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橘和柠 2024-11-09 16:57:23

如果您有 NSURL，则无需使用 NSFileManager 即可使用 resourceValuesForKeys:error:：

NSNumber *fileSize = [url resourceValuesForKeys:@[NSURLFileSizeKey] error:nil][NSURLFileSizeKey];
unsigned long long bytes = fileSize.unsignedLongLongValue;

（ObjC 答案灵感来自 kelin 的 Swift 答案）

If you have an NSURL, you can get the file size without an NSFileManager using resourceValuesForKeys:error::

NSNumber *fileSize = [url resourceValuesForKeys:@[NSURLFileSizeKey] error:nil][NSURLFileSizeKey];
unsigned long long bytes = fileSize.unsignedLongLongValue;

(ObjC answer inspired by kelin's Swift answer)

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