ios读写文件NSFileManager

写文件，创建文件写入内容：

NSString *dataString = @"Hello World"; //NSString 和 NSData 都可以写文件

NSData *data = [NSJSONSerializationdataWithJSONObject:dataStringoptions:NSJSONWritingPrettyPrintederror:nil];

NSArrary *arrary = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

NSString *document = [arrary objectAtIndex:0];

NSString *filePath = [document stringByAppendingPathComponent:@"path.js"];//保存文件地址

NSFileManager *fm = [NSFileManager defaultManager];

if(![fmfileExistsAtPath:savePath])

{            

if([fmcreateFileAtPath:savePathcontents:nilattributes:nil])

NSLog(@"create file success"); 
          //创建文件

if([datawriteToFile:savePathatomically:YES])

                NSLog(@"write success");//写入数据
}

读文件：

NSData *data = [NSJSONSerialization dataWithJSONObject:dataString options:NSJSONWritingPrettyPrinted error:nill];

NSArrary *arrary = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *document = [arrary objectAtIndex:0];

NSString *filePath = [document stringByAppendingPathComponent:@"path.js"];//保存文件地址

NSFileManager *fm = [NSFileManager defaultManager];

if([fm fileExistsAtPath:filePath])
{

NSFileHandle *handler = [NSFileHandle
fileHandleForReadingAtPath:filePath];

NSData *readData = [handler readDateToEndOfFile];

        NSString *result = [[NSStringalloc]initWithData:readDataencoding:NSUTF8StringEncoding];

        NSLog(@"data is %@",result);
}

用来做文件持久化的方式。

当然也可以用plist、数据库、等等。