我想你可以做几件事:
NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:aPath];
[fileHandle seekToEndOfFile];
[fileHandle writeData:[textToWrite dataUsingEncoding:NSUTF8StringEncoding]];
[fileHandle closeFile];
请注意,这会将NSData附加到文件中,而不是NSString.请注意,如果使用NSFileHandle,则必须确保该文件已存在.如果路径中不存在文件,fileHandleForWritingAtPath
将返回nil.看NSFileHandle class reference.
或者你可以:
NSString *contents = [NSString stringWithContentsOfFile:filepath];
contents = [contents stringByAppendingString:textToWrite];
[contents writeToFile:filepath atomically:YES encoding: NSUnicodeStringEncoding error:&err];
我相信第一种方法是最有效的,因为第二种方法涉及在将新内容写入文件之前将文件内容读入NSString.但是,如果您不希望文件包含NSData,并且更愿意将其保留为文本,那么第二个选项将更适合您.
[Update]
NSError* error = nil;
NSString* contents = [NSString stringWithContentsOfFile:filepath
encoding:NSUTF8StringEncoding
error:&error];
if(error) { // If error object was instantiated, handle it.
NSLog(@"ERROR while loading from file: %@", error);
// …
}
[contents writeToFile:filepath atomically:YES
encoding:NSUnicodeStringEncoding
error:&err];
See question on stackoverflow