I want increase the scrolling performance in my table view with images in iphone?

Question

I am new to iphone development.I am parsing a xml and display the title,date,contents and image in the cell,Now the scrolling is not smooth, it struck.How can i increase it.I have already applied lazy loading in another view, i am not able to apply in the new view.So how can i increase the scrolling performance.Can i check for any condition that if image is already loaded in the image view,if so i can stop once again the loading of image view. Please help me out.Thanks.

Answer 1

Hello Warrior,

First of all, check if you're not resizing the images - that takes a lot of computing power, and will slow down the table for sure.

Second of all, check for view hierarchy - complicated view hierarchy means bad performance. Rembemer to use as much opaque views as possible, and when you're using non-opaque views don't make the cells too complex(by complex Apple means three or more custom views). If the views are too complex - use drawRect method for custom drawing of the content.

There's a great example on how to achieve this provided by Apple called AdvancedTableViewCell (here's a link ), and there's a great tutorial by Apple about table view cells (another link ).

I hope this was helpful, Paul

Answer 2

What I do to guarantee fast scrolling in a table is to subclass my own UITableViewCell where I implement all properties that I need.

Whenever that tablecell is initialized I draw the properties of the cell on the cell itself. So when you need an image on there, dont use an UIImageView, but just draw the image on the cell. Also all the text I need I just draw on there.

After a long stuggle finding out how to do all this, I also found a nice blog post about this.

http://blog.atebits.com/2008/12/fast-scrolling-in-tweetie-with-uitableview/