Skip to main content

removeFromSuperview and release memory management



I have a MBProgressHUD that I allocate as follows:







self.progressHUD_ = [[[MBProgressHUD alloc] initWithView:self.view] autorelease];







if I call removeFromSuperview then would I have to call progressHUD release again? Also if I declare a property with something like this:







NSString * title_;



@property (nonatomic, retain) NSString * title_;







then it is guaranteed that in my dealloc I should have a release on title right?


Comments

  1. No, you don't have to release it again. Views retain their subviews and release them again automatically when you call removeFromSuperview. As long as the view has been autoreleased when you attach it to the view, it will be released when it is removed from the view.

    I didn't quite understand your second question, but yes, you have to release any properties of type "retain" or "copy" in your dealloc statement. You have to write those release statements manually, they aren't added automatically (unless you are using ARC of course, which I strongly recommend).

    ReplyDelete
  2. How is your progressHUD_ property defined? (btw, the ivar should have a trailing underscore, but not the property name).

    In case it is defined as (retain, whatever), you will have to release it again:


    When you create it, its retainCount is +1.
    When you assign it to your property, its retainCount will be increased by one.
    When you add it as a subview to the parent view, its retainCount will be increased by one.
    At some point, autorelease will eventually decrease it by 1, but the view and the property still hold on to it.


    So you'll have to either set your property to nil or call release on the ivar in your dealloc method.

    Also, you probably want to use copy instead of retain when defining an NSString property. And yes: you'll have to release it either way.

    ReplyDelete

Post a Comment

Popular posts from this blog

[韓日関係] 首相含む大幅な内閣改造の可能性…早ければ来月10日ごろ=韓国

div not scrolling properly with slimScroll plugin

I am using the slimScroll plugin for jQuery by Piotr Rochala Which is a great plugin for nice scrollbars on most browsers but I am stuck because I am using it for a chat box and whenever the user appends new text to the boxit does scroll using the .scrollTop() method however the plugin's scrollbar doesnt scroll with it and when the user wants to look though the chat history it will start scrolling from near the top. I have made a quick demo of my situation http://jsfiddle.net/DY9CT/2/ Does anyone know how to solve this problem?

Why does this javascript based printing cause Safari to refresh the page?

The page I am working on has a javascript function executed to print parts of the page. For some reason, printing in Safari, causes the window to somehow update. I say somehow, because it does not really refresh as in reload the page, but rather it starts the "rendering" of the page from start, i.e. scroll to top, flash animations start from 0, and so forth. The effect is reproduced by this fiddle: http://jsfiddle.net/fYmnB/ Clicking the print button and finishing or cancelling a print in Safari causes the screen to "go white" for a sec, which in my real website manifests itself as something "like" a reload. While running print button with, let's say, Firefox, just opens and closes the print dialogue without affecting the fiddle page in any way. Is there something with my way of calling the browsers print method that causes this, or how can it be explained - and preferably, avoided? P.S.: On my real site the same occurs with Chrome. In the ex