CODEWITHSUNDEEP
iphone
Maulik
Maulik

Reputation: 19418

core graphics in iphone


I m learning core graphics in iphone. I got basics about how to draw. I want to know how can we put any graphics ,say a circle, in a loop so we can move it ? like in JAVA, we use repaint method.

Upvotes: 2

Views: 488

Answers (2)

Sixten Otto
Sixten Otto

Reputation: 14816

Depending on what you're trying to accomplish, another solution might be to make the element that's moving a separate UIView / CALayer, and animate its position using Core Animation (in which case, the looping and tweening are handled by the system). Highly recommend you start with Getting Started with Graphics and Animation.

Upvotes: 3

hotpaw2
hotpaw2

Reputation: 70733

On an iPhone, you repeatedly call a view's setNeedsDisplay method using an NSTimer or CADisplayLink. The OS then calls your view's drawRect method to repaint the circle, and/or redraw any other core graphics drawing needed.

You don't loop in an event driven framework. You tell the OS to repeatedly call you back, and then exit your code and wait.

Upvotes: 2

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