iOS NSData的相互转换

1、 NSData && NSString

NSData *data = [NSData dataWithContentsOfURL:url];

NSString *str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

NSData *subData = [str dataUsingEncoding:NSUTF8StringEncoding];

2、NSData && UIImage

UIImage *image = [UIImage imageNamed:@"11.png"];

NSData *imageData = UIImageJPEGRepresentation(image, 1);

UIImage *subImage = [UIImage imageWithData:imageData];

3、NSData && NSArray

//利用归档和反归档进行转换

NSArray *array = @[@"1",@"2",@"3"];

NSData *arrayData = [NSKeyedArchiver archivedDataWithRootObject:array];

NSArray *subArray = [NSKeyedUnarchiver unarchiveObjectWithData:arrayData];

4、NSData && NSDictionary

//利用归档和反归档进行转换

NSDictionary *dict = @{@"name":@"zhang",@"age":@"16",@"gender":@"F"};

NSData *dictData = [NSKeyedArchiver archivedDataWithRootObject:dict];

NSDictionary *subDict = [NSKeyedUnarchiver unarchiveObjectWithData:dictData];

5、NSData && NSString && UIImage

//用于存储数据库中的数据

UIImage *image = [UIImage imageNamed:@"11.png"];

NSData *imageData = UIImageJPEGRepresentation(image, 1);

NSString *imageStr = [imageData base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];

NSData *subImageData = [[NSData alloc] initWithBase64EncodedString:imageStr options:NSDataBase64DecodingIgnoreUnknownCharacters];

UIImage *subImage = [UIImage imageWithData:subImageData];