【转】从bundle中复制文件到Documents目录中的代码

下面的代码段转自这个网站，备用：

 http://umlautllama.com/w2/?action=view&page=iPhone%20Helpful%20Coding%20Tips

16. Copy a file from your app bundle to Documents
You may want to include files with your bundle that get copied into your documents folder in the sandbox. The following code is adapted from the Apple "SQLiteBooks" example:

- (void)makeDocumentSubdir:(NSString *)subdirname
{
    // First, test for existence.
    BOOL success;
    NSFileManager *fileManager = [NSFileManager defaultManager];

    // set up the basic directory path name
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    // create the directory path name for the subdirectory
    NSString *subdirectory = [paths objectAtIndex:0];
    subdirectory = [documentsDirectory stringByAppendingPathComponent:subdirname];
    success = [fileManager createDirectoryAtPath:subdirectory withIntermediateDirectories:YES attributes:nil error:NULL ];
}

- (void)copyFileNamed:(NSString *)filename intoDocumentsSubfolder:(NSString *)dirname
{
    // First, test for existence.
    BOOL success;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSError *error;
    // set up the basic directory path name
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    // set up the directory path name for the subdirectory
    NSString *subdirectory = [documentsDirectory stringByAppendingPathComponent:dirname];

    // set up the full path for the destination file
    NSString *writableFilePath = [subdirectory stringByAppendingPathComponent:filename];
    success = [fileManager fileExistsAtPath:writableFilePath];

    // if the file is already there, just return
    if (success)
            return;
    // The file not exist, so copy it to the documents flder.
    NSString *defaultFilePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:filename];
    success = [fileManager copyItemAtPath:defaultFilePath toPath:writableFilePath error:&error];
    if (!success) {
            //[self alert:@"Failed to copy resource file"];
            NSAssert1(0, @"Failed to copy file to documents with message '%@'.", [error localizedDescription]);
    }
}

- (void)firstRunSetup
{
    [self makeDocumentSubdir:@"FileDir1"];
    [self copyFileNamed:@"FirstFile.sqlite" intoDocumentsSubfolder:@"FileDir1"];
    [self copyFileNamed:@"SecondFile.sqlite" intoDocumentsSubfolder:@"FileDir1"];
}