NSFileManager 无法正常工作

Question

我想用 NSFileManager 移动 2 个文件，但它没有移动我的文件：

在 myfolder 有 5 个文本文件，我将删除所有这些文件

我的代码：

BOOL isDir;
if([[NSFileManager defaultManager] fileExistsAtPath:@"/volume/netrt/myfolder/" isDirectory:&isDir]) {
    [[NSFileManager defaultManager] removeItemAtPath:@"/volume/netrt/myfolder/*" error:nil]; // for delete all files
    [[NSFileManager defaultManager] movItemAtPath:@"/rdns/macross/text1.txt" toPath:@"/volume/netrt/myfolder/" error:nil];
    [[NSFileManager defaultManager] movItemAtPath:@"/rdns/macross/text2.txt" toPath:@"/volume/netrt/myfolder/" error:nil];
}

文件夹 myfolder 已经存在。我的错误是什么？

非常感谢

Answer 1

很可能还有其他问题，但对于初学者来说，toPath: 需要一个实际的文件名。

[[NSFileManager defaultManager] movItemAtPath:@"/rdns/macross/text1.txt" toPath:@"/volume/netrt/myfolder/text1.txt" error:nil];

将 "text1.txt" 添加到 toPath: 的末尾。

NSFileManager documentation

Answer 2

您知道，error 参数不是您可以忽略的。您遇到问题但仍然通过 nil？！认真的吗？

如果你已经看过 NSFileManager 告诉你的错误是你就不需要问这个问题了。

Answer 3

下面是演示游乐场的代码，您应该可以使用它来解决您的问题。

// Demo Playground for Whosebug Question
// 

// Shows how to recursively remove all file in a directory by removing the directory and then recreating it.

// Please see the main function first for more explanation


import Cocoa

//Creates Fake Directory with Fake Files
func createFakeDirectoryAtPath(path: String) -> NSError? {

    var isDir = ObjCBool(false)
    if NSFileManager.defaultManager().fileExistsAtPath(path, isDirectory: &isDir) {
        println("INFO> Will not create fake directory, file exists at: \(path).")
        return nil
    }

    var createDirError: NSError?
    NSFileManager.defaultManager().createDirectoryAtPath(path, withIntermediateDirectories: false, attributes: nil, error: &createDirError)

    if let error = createDirError {
        return error
    }
    println("\tINFO> Created Fake Directory Named: \(path.lastPathComponent).")

    for filename in ["one.txt", "two.jpg", "three.png", "four.doc", "five.txt", "six.mp3"] {
        let filepath = path.stringByAppendingPathComponent(filename)
        if NSFileManager.defaultManager().createFileAtPath(filepath, contents: nil, attributes: nil) {
            println("\t\tINFO> Created Fake File Named: \(filename).")
        }
    }


    return nil
}

func createFakeDirectoryStructureAtPath(path: String) -> Bool {

    //Create base directory
    let createDirError = createFakeDirectoryAtPath(path)
    if let error = createDirError {
        println("!ERROR> " + error.localizedDescription)
        return false
    }

    //Creates fake directories
    for dirname in ["one", "two", "three", "four", "five", "six"] {
        let subDirPath = path.stringByAppendingPathComponent(dirname)
        let createSubDirError = createFakeDirectoryAtPath(subDirPath)

        if let error = createSubDirError {
            println("!ERROR> " + error.localizedDescription)
            return false
        }
    }

    return true
}


//Removes a directory at all it's contents
func removeDirectoryAtPath(path: String) {

    var isDir = ObjCBool(false)
    if NSFileManager.defaultManager().fileExistsAtPath(path, isDirectory: &isDir) && isDir {

        var removeDirError: NSError?
        NSFileManager.defaultManager().removeItemAtPath(path, error: &removeDirError)

        if let error = removeDirError {
            println("!ERROR> " + error.localizedDescription)
        }
    }

}


//This is where the demo execution will begin.

// Start by opening the path that will contain the fake directory.
// Then one by one turn use the boolean controls to turn on each step and explore the results of each step.
// Then look at the code to figure out how it's doing what it's doing.

func main() {
    //Controls Location of Fake Directory
    let fakeDirectoryPath = "~/fake-directory".stringByExpandingTildeInPath

    assert(fakeDirectoryPath.lastPathComponent == "fake-directory", "This code will remove the directory and all contents in the directory at path: \(fakeDirectoryPath). If you are ABSOLUTELY sure you want to do this, please update this assertion. Note playground code will automatically execute so you could go up a creek without a paddle if you remove this assertion.")

    println("Open this path: \(    fakeDirectoryPath.stringByDeletingLastPathComponent)\n\n")

    //These Booleans control whether or not execute a step of the demo.

    let setupFakeDirectory = false
    let removeFakeDirectory = false
    let createEmptyDirectory = false
    let removeEmptyDirectory = false


    //Create Fake Directory and Subdirectories with fake files in them.
    if setupFakeDirectory {

        removeDirectoryAtPath(fakeDirectoryPath)

        let success = createFakeDirectoryStructureAtPath(fakeDirectoryPath)
        if success {
            println("Created Fake Directory Structure at Path: \(fakeDirectoryPath)")
        } else {
            println("Didn't Create Fake Directory Structure At Path: \(fakeDirectoryPath)")
        }
    }

    //Removes the fake directory structure
    if removeFakeDirectory {
        removeDirectoryAtPath(fakeDirectoryPath)
    }

    if createEmptyDirectory {
        var createDirError: NSError?
        NSFileManager.defaultManager().createDirectoryAtPath(fakeDirectoryPath, withIntermediateDirectories: false, attributes: nil, error: &createDirError)

        if let error = createDirError {
            println("!ERROR> " + error.localizedDescription)
        }

    }

    if removeEmptyDirectory {
        removeDirectoryAtPath(fakeDirectoryPath)
    }
}

main()

NSFileManager 无法正常工作

NSFileManager does not properly work

objective-c

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