iOS将图像合并到Parse.com

Question

I want to combine two images and send them as one to a Parse database. Only I get no image as result.

This is my code: .h file

#import <UIKit/UIKit.h>
#import <Parse/Parse.h>


@interface mailViewController : UIViewController<UITextFieldDelegate>

@property (weak, nonatomic) IBOutlet UITextField *naamText;
@property (weak, nonatomic) IBOutlet UITextField *emailText;
@property (weak, nonatomic) IBOutlet UIImageView *dankView;
@property (weak, nonatomic) IBOutlet UILabel *label;
@property (weak, nonatomic) IBOutlet UIButton *buttonLogo;
@property (weak, nonatomic) IBOutlet UIImageView *mailImage;
@property (weak, nonatomic) IBOutlet UIImageView *achtergrondImage;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@property (nonatomic, strong) UIImage *coverImage;
@property (nonatomic, strong) UIImage *achtergrond;
//@property (nonatomic, strong) UIImage *finalImage;

 - (IBAction)send:(id)sender;
 - (IBAction)cancel:(id)sender;

 @end

.m file

  #import "mailViewController.h"
  #import "cat01ViewController.h"

@interface mailViewController ()

@property (nonatomic, strong) UIImage *finalImage;

@end

@implementation mailViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

   - (void)viewDidLoad
    {

    self.naamText.delegate = self;
    self.emailText.delegate = self;

    self.mailImage.image = self.coverImage;


    //hide dankwoord
    self.dankView.hidden = YES;
    _label.hidden = YES;
    _buttonLogo.hidden = YES;


    [super viewDidLoad];


}

- (void) viewWillAppear:(BOOL)animated
{
      if (self.coverImage != nil)
        self.mailImage.image = self.coverImage;
}

- (void)addImages{

    UIImage *image1 = self.mailImage.image;
    UIImage *image2 = self.achtergrond;

    CGSize size = CGSizeMake(image1.size.width, image1.size.height + image2.size.height);

    [image1 drawInRect:CGRectMake(0,0,size.width, image1.size.height)];
    [image2 drawInRect:CGRectMake(0,image1.size.height,size.width, image2.size.height)];

    self.finalImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    //Add image to view
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0,               self.finalImage.size.width, self.finalImage.size.height)];
    imageView.image = self.finalImage;
    [self.view addSubview: imageView];

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

    [self.naamText resignFirstResponder];
    [self.emailText resignFirstResponder];
}

-(BOOL)textFieldShouldReturn:(UITextField *)textField{

   if (textField) {
        [textField resignFirstResponder];
    }

    PFObject *emailadres = [PFObject objectWithClassName:@"emailadres"];
    [emailadres setObject:_naamText.text forKey:@"name"];
    [emailadres setObject:_emailText.text forKey:@"email"];
    emailadres[@"iPad_nr"] = @"iPad 2";
    [emailadres saveInBackground];

    self.dankView.hidden = NO;
    _label.hidden = NO;
    _buttonLogo.hidden = NO;


    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 5 * NSEC_PER_SEC),   dispatch_get_main_queue(), ^{
       _label.hidden = YES;
    });

    return NO;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)send:(id)sender {

    [self.naamText resignFirstResponder];
    [self.emailText resignFirstResponder];

    UIImage *image = self.finalImage;

    NSData *imageData = UIImagePNGRepresentation(image);
    PFFile *imageFile = [PFFile fileWithName:@"image.png" data:imageData];

    PFObject *mailPhoto = [PFObject objectWithClassName:@"mailPhoto"];
    mailPhoto[@"imageName"] = @"Ikzieikzie";
    mailPhoto[@"imageFile"] = imageFile;
    [mailPhoto setObject:_naamText.text forKey:@"name"];
    [mailPhoto setObject:_emailText.text forKey:@"email"];
    mailPhoto[@"iPad_nr"] = @"iPad 1";
    [mailPhoto saveInBackground];

    self.dankView.hidden = NO;
    _label.hidden = NO;
    _buttonLogo.hidden = NO;


    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 5 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
        _label.hidden = YES;
    });

}

- (IBAction)cancel:(id)sender {

    [self.naamText resignFirstResponder];
    [self.emailText resignFirstResponder];

    self.dankView.hidden = NO;
    _label.hidden = NO;
    _buttonLogo.hidden = NO;


    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 5 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
        _label.hidden = YES;
    });

}

@end

So, I know how to send the images individual to the Parse database... but I cant understand how to combine them and send them as one.

Answer 1

You set the local variable finalImage in addImages , you never set a class variable self.finalImage to contain the combined image, so this line

UIImage *image = self.finalImage;

probably sets image to nil.

Also, you never add the UIImageView *imageView in addImages as a subview as you've probably intended.

So to fix this code, I'd recommend creating defining finalImage as a class property at the top of the class, ex:

@interface ViewController ()

@property (nonatomic, strong) UIImage *finalImage;

@end

Then in addImages you can change the local variable finalImage to self.finalImage and properly add the UIImageView as a subview, ex:

self.finalImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

//Add image to view
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.finalImage.size.width, self.finalImage.size.height)];
imageView.image = self.finalImage;
[self.view addSubview: imageView];

After making these changes you can still use this line in send: :

UIImage *image = self.finalImage; 

Answer 2

You have misplaced the context, it should be focused to imageview object not to the image object. Try this:

UIImage *image1 = self.mailImage.image;
UIImage *image2 = self.achtergrond;

CGSize size = CGSizeMake(image1.size.width, image1.size.height + image2.size.height);

[image1 drawInRect:CGRectMake(0,0,size.width, image1.size.height)];
[image2 drawInRect:CGRectMake(0,image1.size.height,size.width, image2.size.height)];

UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();

//Add image to view
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, finalImage.size.width, finalImage.size.height)];

UIGraphicsBeginImageContext(size);

imageView.image = finalImage;

UIGraphicsEndImageContext();

Hope this helps.

Answer 3

So, this is the final solution! Thanks for your help!

UIImage *image1 = self.achtergrondImage.image;
UIImage *image2 = self.mailImage.image;

UIGraphicsBeginImageContext(image1.size);
[image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];
[image2 drawInRect:CGRectMake(image1.size.width - image2.size.width, image1.size.height - image2.size.height, image2.size.width, image2.size.height)];

self.finalImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.finalImage.size.width, self.finalImage.size.height)];
imageView.image = self.finalImage;