ios 如何在 Swift 中访问包含在应用程序包中的文件？
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How to access file included in app bundle in Swift?
提问by atirit
I know there are a few questions pertaining to this, but they're in Objective-C.
我知道有一些与此相关的问题，但它们在 Objective-C 中。
How can I access a .txtfile included in my app using Swift on an actual iPhone? I want to be able to read and write from it. Hereare my project files if you want to take a look. I'm happy to add details if necessary.
如何在实际 iPhone 上.txt使用 Swift访问我的应用程序中包含的文件？我希望能够从中读取和写入。如果你想看一看，这是我的项目文件。如有必要，我很乐意添加详细信息。
回答by Karim H
Simply by searching in the app bundle for the resource
只需在应用程序包中搜索资源
var filePath = NSBundle.mainBundle().URLForResource("file", withExtension: "txt")
However you can't write to it because it is in the app resources directory and you have to create it in the document directory to write to it
但是你不能写入它，因为它在应用程序资源目录中，你必须在文档目录中创建它才能写入它
var documentsDirectory: NSURL?
var fileURL: NSURL?
documentsDirectory = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).last!
fileURL = documentsDirectory!.URLByAppendingPathComponent("file.txt")
if (fileURL!.checkResourceIsReachableAndReturnError(nil)) {
print("file exist")
}else{
print("file doesnt exist")
NSData().writeToURL(fileURL!,atomically:true)
}
now you can access it from fileURL
现在您可以从fileURL访问它
EDIT - 28 August 2018
编辑 - 2018 年 8 月 28 日
This is how to do it in Swift 4.2
这是在Swift 4.2 中的方法
var filePath = Bundle.main.url(forResource: "file", withExtension: "txt")
To create it in the document directory
在文档目录中创建它
if let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last {
let fileURL = documentsDirectory.appendingPathComponent("file.txt")
do {
if try fileURL.checkResourceIsReachable() {
print("file exist")
} else {
print("file doesnt exist")
do {
try Data().write(to: fileURL)
} catch {
print("an error happened while creating the file")
}
}
} catch {
print("an error happened while checking for the file")
}
}
回答by Philippe-André Lorin
Swift 3, based on Karim's answer.
Swift 3，基于Karim 的回答。
Reading
读
You can read files included in an app's bundle through the bundle's resource:
您可以通过捆绑包的资源读取应用程序捆绑包中包含的文件：
let fileURL = Bundle.main.url(forResource:"filename", withExtension: "txt")
Writing
写作
However, you can't write there. You will need to create a copy, preferably in the Documents directory:
但是，你不能在那里写。您需要创建一个副本，最好在 Documents 目录中：
func makeWritableCopy(named destFileName: String, ofResourceFile originalFileName: String) throws -> URL {
// Get Documents directory in app bundle
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last else {
fatalError("No document directory found in application bundle.")
}
// Get URL for dest file (in Documents directory)
let writableFileURL = documentsDirectory.appendingPathComponent(destFileName)
// If dest file doesn't exist yet
if (try? writableFileURL.checkResourceIsReachable()) == nil {
// Get original (unwritable) file's URL
guard let originalFileURL = Bundle.main.url(forResource: originalFileName, withExtension: nil) else {
fatalError("Cannot find original file “\(originalFileName)” in application bundle's resources.")
}
// Get original file's contents
let originalContents = try Data(contentsOf: originalFileURL)
// Write original file's contents to dest file
try originalContents.write(to: writableFileURL, options: .atomic)
print("Made a writable copy of file “\(originalFileName)” in “\(documentsDirectory)\\(destFileName)”.")
} else { // Dest file already exists
// Print dest file contents
let contents = try String(contentsOf: writableFileURL, encoding: String.Encoding.utf8)
print("File “\(destFileName)” already exists in “\(documentsDirectory)”.\nContents:\n\(contents)")
}
// Return dest file URL
return writableFileURL
}
Example usage:
用法示例：
let stuffFileURL = try makeWritableCopy(named: "Stuff.txt", ofResourceFile: "Stuff.txt")
try "New contents".write(to: stuffFileURL, atomically: true, encoding: String.Encoding.utf8)
回答by CodeBender
Just a quick update for using this code with Swift 4:
只是在 Swift 4 中使用此代码的快速更新：
Bundle.main.url(forResource:"YourFile", withExtension: "FileExtension")
And the following has been updated to account for writing the file out:
并且已更新以下内容以说明写出文件：
var myData: Data!
func checkFile() {
if let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last {
let fileURL = documentsDirectory.appendingPathComponent("YourFile.extension")
do {
let fileExists = try fileURL.checkResourceIsReachable()
if fileExists {
print("File exists")
} else {
print("File does not exist, create it")
writeFile(fileURL: fileURL)
}
} catch {
print(error.localizedDescription)
}
}
}
func writeFile(fileURL: URL) {
do {
try myData.write(to: fileURL)
} catch {
print(error.localizedDescription)
}
}
This particular example is not the most flexible, but with a little bit of work you can easily pass in your own file names, extensions and data values.
这个特殊的例子并不是最灵活的，但是通过一些工作，您可以轻松地传递您自己的文件名、扩展名和数据值。
回答by MirekE
Bundles are read only. You can use NSBundle.mainBundle().pathForResourceto access the file as read-only, but for read-write access you need to copy your document to Documents folder or tmp folder.
捆绑包是只读的。您可以使用NSBundle.mainBundle().pathForResource以只读方式访问文件，但要进行读写访问，您需要将文档复制到 Documents 文件夹或 tmp 文件夹。
回答by Mithilesh Kuamr
Get File From Bundle in Swift 5.1
在 Swift 5.1 中从包中获取文件
//For Video File
let stringPath = Bundle.main.path(forResource: "(Your video file name)", ofType: "mov")
let urlVideo = Bundle.main.url(forResource: "Your video file name", withExtension: "mov")
回答by T.Nhan
Bundles can be written. You can use Bundle.main.pathto overwrite file by adding it into Copy Bundles Resource.
可以写包。您可以Bundle.main.path通过将文件添加到Copy Bundles Resource.
