Question

I have created UITableCellView class called NoteCell. The header defines the following:

#import <UIKit/UIKit.h> #import 'Note.h'  @interface NoteCell : UITableViewCell {     Note *note;     UILabel *noteTextLabel;   }  @property (nonatomic, retain) UILabel *noteTextLabel;  - (Note *)note; - (void)setNote:(Note *)newNote;   @end 

In the implementation I have the following code for the setNote: method:

- (void)setNote:(Note *)newNote {     note = newNote;     NSLog(@'Text Value of Note = %@', newNote.noteText);     self.noteTextLabel.text = newNote.noteText;     NSLog(@'Text Value of Note Text Label = %@', self.noteTextLabel.text);     [self setNeedsDisplay]; } 

This fails to set the text field of the UILabel and the output of the log messages is:

2008-11-03 18:09:05.611 VisualNotes[5959:20b] Text Value of Note = Test Note 1   2008-11-03 18:09:05.619 VisualNotes[5959:20b] Text Value of Note Text Label = (null) 

I have also tried to set the text field of UILabel using the following syntax:

[self.noteTextLabel setText:newNote.noteText]; 

This does not seem to make a difference.

Any help would be much appreciated.

Answer 1

Have you set up your noteTextLabel anywhere? What this looks like to me is that you’re messaging a nil object. When you cell is created, noteTextLabel is nil. If you never set it up, you’re basically doing the following:

[nil setText: newNote.noteText]; 

And when you later try to access it, you’re doing this:

[nil text]; 

Which will return nil.

In your -initWithFrame:reuseIdentifier: method, you need to explicitly create your noteTextLabel, and add it as a subview to your cell’s content view:

self.noteTextLabel = [[[UILabel alloc] initWithFrame: CGRectMake(0, 0, 200, 20)] autorelease]; [self.contentView addSubview: self.noteTextLabel]; 

Then this should work.

Also, as a stylistic note, I would make the property for noteTextLabel readonly, since you’re only going to want to access it from outside the class, never set it.