No access to UILabel - ios

Question

I am setting an UILabel inside of the cellForRowAtIndexPath method and when the user changes the text, the label should change. But even it is not nil, it doesn't change.
#property UILabel *myLabel;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
self.myLabel = [[UILabel alloc] initWithFrame:CGRectMake(5, 0, textView.frame.size.width, 37)];
self.myLabel.text = #"Old Text";
}
- (void)textViewDidChange:(UITextView *)textView {
self.myLabel.textColor = [UIColor redColor];
self.myLabel.text = #"New Text";
}
I found a solution where some people are changing the UILabel in the main thread but that's not working for me.
dispatch_async(dispatch_get_main_queue(), ^{
// Do in main thread
});

Answer 1

If you want to modify the label of a cell that's on-screen "on the fly" then you need a way to reach the label.
What I usually do is to create a template for the cell in IB, define a custom subclass of UITableViewCell, and set the cell's class to that custom subclass. Then I connect outlets between the cell and all the custom fields I've created.
In my cellForRowAtIndexPath method, I dequeue a cell and cast it to my custom type. Then I reference the fields in the cell through the cell, e.g.
cell.myLabel.
If you add a new field to your cell in cellForRowAtIndexPath you have a couple of problems. First, you need to make sure you don't add another copy of that new field when you recycle the cell. Second, you need a way to get to the field if you want to modify it, as in your question. There are ways to deal with these problems, but the approach I outlined above is cleaner.

Answer 2

Duncan, I'm sorry, here is the rest of the cellForRowAtIndexPath. I thought it could not be a problem of reusing the cell as I'm not scrolling so the cell should not be recreated.
#property NSString *textField_1;
#property NSString *textField_2;
// ...
#property UILabel *myLabel;
#end
#implementation TableViewController
- (void)textViewDidChange:(UITextView *)textView
{
self.myLabel.textColor = [UIColor redColor];
self.myLabel.text = #"New Text";
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = #"SimpleTableCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
if(indexPath.section == 0)
{
float displayResolutionWidth = self.view.frame.size.width;
UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, displayResolutionWidth - 165, 50)];
textField.delegate = self;
textField.tag = indexPath.row;
textField.autoresizingMask = UIViewAutoresizingFlexibleWidth;
UITextView *textView = [[UITextView alloc]initWithFrame:CGRectMake(0, 0, displayResolutionWidth - 90, 176)];
textView.delegate = self;
textView.tag = indexPath.row;
textView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
self.myLabel = [[UILabel alloc] initWithFrame:CGRectMake(5, 0, textView.frame.size.width, 37)];
self.myLabel.textColor = [UIColor redColor];
if(indexPath.row == 17)
{
cell.accessoryView = textView;
[textView addSubview:self.myLabel];
}
else if (indexPath.row != 17)
{
cell.accessoryView = textField;
}
if (self.object)
{
if (indexPath.row == 0)
textField.text = self.object.property_1;
if (indexPath.row == 1)
textField.text = self.object.property_2;
}
else if (!self.object)
{
if (indexPath.row == 0)
textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:NSLocalizedString(#"Placeholder_1", #"")
attributes:#{NSForegroundColorAttributeName: [UIColor greenColor]}];
if (indexPath.row == 1)
textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:NSLocalizedString(#"Placeholder_2", #"")
attributes:#{NSForegroundColorAttributeName: [UIColor greenColor]}];
if (indexPath.row == 17)
self.myLabel.text = "Old Text";
}
if (indexPath.row != 17)
{
cell.textLabel.text = [self.arrayWithObjectData objectAtIndex:indexPath.row];
}
else if (indexPath.row == 17)
{
UILabel *mylabel = [[UILabel alloc] initWithFrame:CGRectMake(16, 0, 150, 40)];
mylabel.text = self.arrayWithObjectData[17];
mylabel.textColor = [UIColor COLOR_TEXT];
[cell.contentView addSubview:mylabel];
}
}
return cell;
}
#end