Obj-C，如何使用NSSearchPathForDirectoriesInDomains复制文件？

Question

I want to copy some files as part of a backup routine.

I have the following function which gives the location of my files.

- (NSString *)getLocalDocumentPath:(NSString*)strFile {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, 
           NSUserDomainMask, YES);
    NSString *path = [[paths objectAtIndex:0] 
           stringByAppendingPathComponent:strFile];
    return path;
}

Heres my database

    NSString *filePath = [self getLocalDocumentPath:@"mydatabase.db"];

I want to copy this to a new file called upload.txt

    NSString *filePath = [self getLocalDocumentPath:@"upload.txt"];

Then later on I download a file.

    NSString *filePath = [self getLocalDocumentPath:@"download.txt"];

Which I want to copy on top of my original database file.

    NSString *filePath = [self getLocalDocumentPath:@"mydatabase.db"];

Answer 1

Sounds like you want to get to know NSFileManager very well (documentation is linked for you).

The method you'd most likely be most interested in is:

moveItemAtPath:toPath:error:

Answer 2

one method could be:
you can read the file contents you want to save in NSData then can use:

- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile

in which you can replace the path with one your relative file paths you have mentioned for various files.

Answer 3

NSFileManager *fileManager = [NSFilemanager defaultManager];
[fileManager copyItemAtPath:databasePath toPath:uploadFilePath error:nil];

and if you want to overwrite the database using the download.txt, make an instance of NSData and use - (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile