我可以下载的二进制文件保存到自定义名称完全正常的“文档”文件夹。
如果我只是改变的URL，而不是“文档”文件夹中的“应用程序支持”文件夹中，它没有写入该URL说它不存在。
这里的URL结构的代码：
- ( NSURL * ) getSaveFolder
{
NSURL * appSupportDir = nil;
NSURL * appDirectory = nil;
NSArray * possibleURLs = [[NSFileManager defaultManager] URLsForDirectory:NSApplicationSupportDirectory inDomains:NSAllDomainsMask];
if ( [possibleURLs count] >= 1 )
{
appSupportDir = [possibleURLs objectAtIndex:0];
}
if ( appSupportDir != nil)
{
NSString * appBundleID = [[NSBundle mainBundle] bundleIdentifier];
appDirectory = [appSupportDir URLByAppendingPathComponent:appBundleID];
}
return appSupportDir;
}
这里是保存代码：
- ( void ) writeOutDataToFile:( NSData * )data
{
NSURL * finalURL = [self.rootPathURL URLByAppendingPathComponent:self.aFileName];
[data writeToURL:finalURL atomically:YES];
}
如果我改变的NSArray到：
NSArray * possibleURLs = [[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask];
然后将其保存的罚款。
我读过的苹果文档上的文件的东西，无法修复这个 - 我缺少什么？
不同的是Documents目录， Application Support目录不默认情况下应用程序的沙盒存在。 您需要创建它，然后才能使用它。
而一个更简单的方法去的目录一提的是：
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
NSString *appSupportDirectory = paths.firstObject;
如果有人不知如何做rmaddy描述：
NSString *appSupportDir = [NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES) lastObject];
//If there isn't an App Support Directory yet ...
if (![[NSFileManager defaultManager] fileExistsAtPath:appSupportDir isDirectory:NULL]) {
NSError *error = nil;
//Create one
if (![[NSFileManager defaultManager] createDirectoryAtPath:appSupportDir withIntermediateDirectories:YES attributes:nil error:&error]) {
NSLog(@"%@", error.localizedDescription);
}
else {
// *** OPTIONAL *** Mark the directory as excluded from iCloud backups
NSURL *url = [NSURL fileURLWithPath:appSupportDir];
if (![url setResourceValue:@YES
forKey:NSURLIsExcludedFromBackupKey
error:&error])
{
NSLog(@"Error excluding %@ from backup %@", url.lastPathComponent, error.localizedDescription);
}
else {
NSLog(@"Yay");
}
}
}
我碰到了同样的问题，并决定使用一个更简洁的方法：
let fileManager = NSFileManager.defaultManager()
let urls = fileManager.URLsForDirectory(.ApplicationSupportDirectory, inDomains: .UserDomainMask) as! [NSURL]
if let applicationSupportURL = urls.last {
fileManager.createDirectoryAtURL(applicationSupportURL, withIntermediateDirectories: true, attributes: nil, error: nil)
}
这工作，因为createDirectoryAtURL使用withIntermediateDirectories: true如果不存在，只创建文件夹。
这里有一个可以写入二进制数据文件的应用程序支持目录iOS的一些SWIFT CODE。 这部分是由chrysAllwood答案的启发。
/// Method to write a file containing binary data to the "application support" directory.
///
/// - Parameters:
/// - fileName: Name of the file to be written.
/// - dataBytes: File contents as a byte array.
/// - optionalSubfolder: Subfolder to contain the file, in addition to the bundle ID subfolder.
/// If this is omitted no extra subfolder is created/used.
/// - iCloudBackupForFolder: Specify false to opt out from iCloud backup for whole folder or
/// subfolder. This is only relevant if this method call results in
/// creation of the folder or subfolder, otherwise it is ignored.
/// - Returns: Nil if all OK, otherwise text for a couple of non-Error errors.
/// - Throws: Various errors possible, probably of type NSError.
public func writeBytesToApplicationSupportFile(_ fileName : String,
_ dataBytes : [UInt8],
optionalSubfolder : String? = nil,
iCloudBackupForFolder : Bool = true)
throws -> String? {
let fileManager = FileManager.default
// Get iOS directory for "application support" files
let appSupportDirectory =
fileManager.urls(for: .applicationSupportDirectory, in: .userDomainMask).first
if appSupportDirectory == nil {
return "Unable to determine iOS application support directory for this app."
}
// Add "bundle ID" as subfolder. This is recommended by Apple, although it is probably not
// necessary.
if Bundle.main.bundleIdentifier == nil {
return "Unable to determine bundle ID for the app."
}
var mySupportDirectory =
appSupportDirectory!.appendingPathComponent(Bundle.main.bundleIdentifier!)
// Add an additional subfolder if that option was specified
if optionalSubfolder != nil {
mySupportDirectory = appSupportDirectory!.appendingPathComponent(optionalSubfolder!)
}
// Create the folder and subfolder(s) as needed
if !fileManager.fileExists(atPath: mySupportDirectory.path) {
try fileManager.createDirectory(atPath: mySupportDirectory.path,
withIntermediateDirectories: true, attributes: nil)
// Opt out from iCloud backup for this subfolder if requested
if !iCloudBackupForFolder {
var resourceValues : URLResourceValues = URLResourceValues()
resourceValues.isExcludedFromBackup = true
try mySupportDirectory.setResourceValues(resourceValues)
}
}
// Create the file if necessary
let mySupportFile = mySupportDirectory.appendingPathComponent(fileName)
if !fileManager.fileExists(atPath: mySupportFile.path) {
if !fileManager.createFile(atPath: mySupportFile.path, contents: nil, attributes: nil) {
return "File creation failed."
}
}
// Write the file (finally)
let fileHandle = try FileHandle(forWritingTo: mySupportFile)
fileHandle.write(NSData(bytes: UnsafePointer(dataBytes), length: dataBytes.count) as Data)
fileHandle.closeFile()
return nil
}
一个班轮 - 将创建如有必要过于：
[[NSFileManager defaultManager] URLForDirectory:NSApplicationSupportDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:nil]
文章来源: iOS: Can't save file to 'Application Support' folder, but can to 'Documents'
