小编nic*_*ice的帖子

例如,我在这里有一个对象

var obj = {a:1,b:2,c:3}

我怎么能得到一个字符串"obj"的obj'name？

我使用imageWithData方法创建一个UIimage：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
UIImage *chosenImage = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data1 = UIImageJPEGRepresentation(chosenImage, 1);
NSData *data2 = UIImageJPEGRepresentation(chosenImage, 0.5);
NSLog(@"data1 = %lu;;;;;;;data2 = %lu",[data1 length],[data2 length]);

UIImage *nimg = [UIImage imageWithData:data2];
NSData *data30 = UIImageJPEGRepresentation(nimg, 1);
NSData *data31 = UIImageJPEGRepresentation(nimg, 0.8);
NSLog(@"data30 = %lu;;;;;;data31 = %lu;;;;;;",[data30 length],[data31 length]);
}

我得到以下输出：

data1 = 1751828;;;;;;;data2 = 254737

data30 = 1368455;;;;;;data31 = 387174;;;;;;

为什么data30比data2大得多？