ios 使用Swift删除iOS目录中的文件

Delete files in iOS directory using Swift

提问by Fabian Boulegue

I downloaded some PDF files in my app and want to delete these on closing the application.

我在我的应用程序中下载了一些 PDF 文件，并希望在关闭应用程序时删除这些文件。

For some reason it does not work:

由于某种原因，它不起作用：

Creating the file:

创建文件：

let reference = "test.pdf"    
let RequestURL = "http://xx/_PROJEKTE/xx\(self.reference)"
let ChartURL = NSURL(string: RequestURL)

//download file
let documentsUrl =  NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first! as NSURL
let destinationUrl = documentsUrl.URLByAppendingPathComponent(ChartURL!.lastPathComponent!)
if NSFileManager().fileExistsAtPath(destinationUrl.path!) {
    print("The file already exists at path")
} else {
    //  if the file doesn't exist
    //  just download the data from your url
    if let ChartDataFromUrl = NSData(contentsOfURL: ChartURL!){
        // after downloading your data you need to save it to your destination url
        if ChartDataFromUrl.writeToURL(destinationUrl, atomically: true) {
            print("file saved")
            print(destinationUrl)
        } else {
            print("error saving file")
        }
    }
}

Then I want to call the test()function to remove the items, like this:

然后我想调用该test()函数来删除项目，如下所示：

func test(){

    let fileManager = NSFileManager.defaultManager()
    let documentsUrl =  NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first! as NSURL

    do {
        let filePaths = try fileManager.contentsOfDirectoryAtPath("\(documentsUrl)")
        for filePath in filePaths {
            try fileManager.removeItemAtPath(NSTemporaryDirectory() + filePath)
        }
    } catch {
        print("Could not clear temp folder: \(error)")
    }
}

采纳答案by TwoStraws

I believe your problem is on this line:

我相信你的问题是在这条线上：

let filePaths = try fileManager.contentsOfDirectoryAtPath("\(documentsUrl)")

You're using contentsOfDirectoryAtPath()with something that is an NSURL. You choose either path strings or URLs, not try to mix them both. To pre-empty your possible next question, URLs are preferred. Try using contentsOfDirectoryAtURL()and removeItemAtURL().

您正在使用contentsOfDirectoryAtPath()的东西，是一个NSURL。您可以选择路径字符串或 URL，而不是尝试将两者混合使用。为了预先清空您可能的下一个问题，首选 URL。尝试使用contentsOfDirectoryAtURL()和removeItemAtURL()。

Another curious thing you should look at once you resolve the above: why are you using NSTemporaryDirectory()for the file path when you try to delete? You're reading the document directory and should use that.

解决上述问题后，您应该看看另一件奇怪的事情：为什么NSTemporaryDirectory()在尝试删除时使用文件路径？您正在阅读文档目录，应该使用它。

回答by Saleh Masum

This code works for me. I removed all the images that were cached.

这段代码对我有用。我删除了所有缓存的图像。

private func test(){

    let fileManager = NSFileManager.defaultManager()
    let documentsUrl =  NSFileManager.defaultManager().URLsForDirectory(.CachesDirectory, inDomains: .UserDomainMask).first! as NSURL
    let documentsPath = documentsUrl.path

    do {
        if let documentPath = documentsPath
        {
            let fileNames = try fileManager.contentsOfDirectoryAtPath("\(documentPath)")
            print("all files in cache: \(fileNames)")
            for fileName in fileNames {

                if (fileName.hasSuffix(".png"))
                {
                    let filePathName = "\(documentPath)/\(fileName)"
                    try fileManager.removeItemAtPath(filePathName)
                }
            }

            let files = try fileManager.contentsOfDirectoryAtPath("\(documentPath)")
            print("all files in cache after deleting images: \(files)")
        }

    } catch {
        print("Could not clear temp folder: \(error)")
    }
}

**** Update swift 3 ****

**** 更新 swift 3 ****

        let fileManager = FileManager.default
        let documentsUrl =  FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first! as NSURL
        let documentsPath = documentsUrl.path

        do {
            if let documentPath = documentsPath
            {
                let fileNames = try fileManager.contentsOfDirectory(atPath: "\(documentPath)")
                print("all files in cache: \(fileNames)")
                for fileName in fileNames {

                    if (fileName.hasSuffix(".png"))
                    {
                        let filePathName = "\(documentPath)/\(fileName)"
                        try fileManager.removeItem(atPath: filePathName)
                    }
                }

                let files = try fileManager.contentsOfDirectory(atPath: "\(documentPath)")
                print("all files in cache after deleting images: \(files)")
            }

        } catch {
            print("Could not clear temp folder: \(error)")
        }