Setting the value of a UITextField in an IBAction

I'm trying to use a UITextField as an output for a simple encryption. The field starts out with a nil string (its default behavior), and I try to update it in the encryptButtonPressed: action. I know I'm getting a good NSString into ciphertext, and I'm getting no errors or warnings or anything that the method doesn't exist, but the field remains blank. Any ideas?

Here's the header:

@interface FirstViewController : UIViewController <UITextFieldDelegate> {


    IBOutlet UITextField *affineKeyField;
    IBOutlet UITextField *shiftKeyField;

    IBOutlet UITextField *messageField;
    IBOutlet UITextField *ciphertextField;

    MAAffineMachine* machine;
}

@property (nonatomic, retain) UITextField *affineKeyField;
@property (nonatomic, retain) UITextField *shiftKeyField;

@property (nonatomic, retain) UITextField *messageField开发者_运维知识库;
@property (nonatomic, retain) UITextField *ciphertextField;


@property (nonatomic, retain) UIButton *encryptButton;
@property (nonatomic, retain) UIButton *clipboardButton;

- (IBAction)encryptButtonPressed:(id)sender;
- (IBAction)clipboardButtonPressed:(id)sender;

@end

And the action, defined in the controller's implementation:

- (IBAction)encryptButtonPressed:(id)sender {
    NSLog(@"Encrypt Button pushed.\n");
    int affine = [[affineKeyField text] intValue];
    int shift = [[shiftKeyField text] intValue];
    NSString* message = [messageField text];
    NSLog(@"%d, %d, %@", affine, shift, message);
    NSString* ciphertext = [machine encryptedStringFromString:message
                                                    ForAffine:affine
                                                        Shift:shift];
    NSLog(@"%@\n", ciphertext);
    [[self ciphertextField] setText: ciphertext];
}

If ciphertext has a proper value, you should check that ciphertextField is linked properly in the interface builder.

Try [[self ciphertextField] setText: ciphertext] -> [ciphertextField setText: ciphertext] or cipherTextField.text = ciphertext;