Databases
StackOverflow2013
Postsdbo
POUIButton not setting alpha properly
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POUIButton not setting alpha properly
    primarykey
    data
    text
    <p>This is probably a stupid mistake of mine, but I have 3 UIbuttons, 2 of which are hidden by default, and 1 which is supposed to reveal the 2 others when clicked on. I call this method in my viewDidLoad:</p> <pre><code>-(void) initButtons { self.checkbutton = [[UIButton alloc] initWithFrame:CGRectMake(20, 330, 80, 70)]; self.checkbutton.backgroundColor = [UIColor clearColor]; [self.checkbutton setBackgroundImage:[UIImage imageNamed:@"checkbutton"] forState:UIControlStateNormal]; self.checkbutton.enabled = NO; self.checkbutton.alpha = 0.0; [self.view addSubview:self.checkbutton]; self.xbutton = [[UIButton alloc] initWithFrame:CGRectMake(230, 330, 70, 70)]; self.xbutton.backgroundColor = [UIColor clearColor]; [self.xbutton setBackgroundImage:[UIImage imageNamed:@"X.png"] forState:UIControlStateNormal]; self.xbutton.enabled = NO; self.xbutton.alpha = 0.0; [self.view addSubview:self.xbutton]; } </code></pre> <p>And when my visible button is clicked, this method is called:</p> <pre><code>-(void) showbuttons { self.checkbutton.enabled = YES; [[self checkbutton] setAlpha:1.0]; self.xbutton.enabled = YES; [[self xbutton] setAlpha:1.0]; NSLog(@"xbutton alpha: %f", [[self xbutton] alpha]); NSLog(@"checkbutton alpha: %f", [[self checkbutton] alpha]); } </code></pre> <p>What happens is that when I click the visible button, only 1 button appears. (xbutton) They should be coded in the exact same way, I don't know what's wrong. The NSLogs that I have show that both buttons have an alpha value of 1.0. I'm sure I @propertied and @synthesized checkbutton correctly, it's just like the xbutton.</p> <p>What am I doing wrong?</p> <p>Also, a side question: what's the difference between <code>[checkbutton setAlpha]</code> and <code>[self.checkbutton setAlpha]</code>?</p> <p>Ughh... My fault. My image was named checkmark.png and not checkbutton.png. Thanks to @DanielRHicks for answering my side question though.</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USCole
    1. USCole
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COThe difference between the `self` and non-`self` versions of `@synthesized` properties on REFERENCE is negligible -- the first uses the getter while the second references the instance variable directly. The difference on ASSIGNMENT, of course, is substantial, since the first manages retaining (if defined that way) while the second sets the instance variable without any retain management.
      singulars
      1. POUIButton not setting alpha properly
      1. USHot Licks
    2. CO@Daniel When you say assignment, do you mean any setting of values? (like setAlpha) Or just when you're allocating and initializing it?
      singulars
      1. POUIButton not setting alpha properly
      1. USCole
    3. CO`self.object = someObject;` is equivalent to `setObject(someObject);`. But `object = someObject;` is NOT equivalent to either of the others, and if the property `object` is being retained, that last assignment will fail to retain it (and likewise fail to unretain the previous value in the property), leading to a likely storage bug and crash.
      singulars
      1. POUIButton not setting alpha properly
      1. USHot Licks
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload