如何将二进制数据转换为NSDATA

Question

我已将UIImageView转换为NSDATA，并将其存储为二进制数据。但是我不知道如何将二进制数据检索到NSDATA并将其转换为uiimageView

我的代码在

下面

图像另存为二进制数据----

-(void) save
{
    UIImage *img = [UIImage imageNamed:@"back2.png"];
    NSData *dataObj =UIImagePNGRepresentation(img);
    NotesDetails *notesDetails = (NotesDetails *) [NSEntityDescription insertNewObjectForEntityForName:@"NotesDetails" inManagedObjectContext:managedObjectContext];
 notesDetails.imageData=dataObj;
    NSLog(@"NotesDetails: %@",notesDetails);
    NSError *error;
    if (![managedObjectContext save:&error])
    {
    }
}

图像重试-------

-(void)viewDidLoad
{
    NSFetchRequest *fectchreq = [[NSFetchRequest alloc] init];
    NSEntityDescription *entitydes = [NSEntityDescription entityForName:@"NotesDetails"
                                                 inManagedObjectContext:self.managedObjectContext];
    [fectchreq setEntity:entitydes];
    NSSortDescriptor *sortdes = [[NSSortDescriptor alloc] initWithKey:@"notesTime" ascending:YES];
    NSArray *sortdesarray = [[NSArray alloc] initWithObjects:sortdes, nil];
    [fectchreq setSortDescriptors:sortdesarray];
    NSError *error;
    NSMutableArray *storeddata = [[self.managedObjectContext executeFetchRequest:fectchreq error:&error] mutableCopy];
    if ([storeddata count] > 0)
    {
        for (NotesDetails *sc in storeddata)
        {
            imgFromDb=[NSData dataWithData:[@"%@",sc.imageData]];
        }
    }
    NSLog(@"Image : %@",imgFromDb);
    UIImageView *dbImage=[[UIImageView alloc]initWithFrame:CGRectMake(80,20,90,90)];
    dbImage.image=[UIImage imageWithData:imgFromDb];
    [NoteDetails addSubview:dbImage];
}

Answer 1

您可以使用nskeyedunarchiver：

imgFromDb= [NSKeyedUnarchiver unarchiveObjectWithData: sc.imageData];

，如果您喜欢nskeyedarachiver，则可以与nskeyedarachiver进行相反的操作（对数据）。例如，还有其他方法可以：

imgFromDb= [UIImage imageWithData: sc.imageData];